Curriculum Lungs Diseases | The Common Vein

III Inflammation – Immune

Disease / Diagnosis (Standard Link)	Grouped Category	Alternative Names	Definition & Comment	Imaging Features	Structure	Category	Faces & Cases	Art & Music
Acute Interstitial Pneumonia (AIP)	Diffuse alveolar damage	Hamman-Rich Syndrome	Definition: Idiopathic, rapidly progressive interstitial pneumonia (DAD). Comment: Requires exclusion of known causes of DAD.	• Diffuse Ground-Glass Opacity (GGO) • Dependent consolidation • Traction bronchiectasis (late)	Alveoli / Interstitium	Inflammation	Songs Lungs Diseases	Song
Acute Respiratory Distress Syndrome (ARDS)	Diffuse alveolar damage	Non-cardiogenic pulmonary edema; Shock lung	Definition: Acute diffuse inflammatory lung injury leading to increased vascular permeability. Comment: Berlin Criteria: Acute onset, bilateral opacities, not explained by heart failure.	• Diffuse bilateral GGO & consolidation • Anterior-posterior density gradient • “Crazy paving” (subacute) • Traction bronchiectasis (late)	Alveoli / Interstitium	Inflammation	Faces of ARDS	Song
Allergic Bronchopulmonary Aspergillosis (ABPA)	Hypersensitivity airway	ABPA	Definition: Hypersensitivity reaction to Aspergillus colonization in Asthma/CF. Comment: Causes eosinophilia and central airway damage.	• Central bronchiectasis • Finger-in-glove mucoid impaction • High-attenuation mucus	Central Bronchi	Inflammation	Faces of ABPA Cases of ABPA	Song
ANCA-Associated Vasculitis	Small-vessel vasculitis	GPA (Wegener’s); MPA	Definition: Autoimmune vasculitis affecting lung capillaries and kidneys. Comment: Can cause life-threatening Diffuse Alveolar Hemorrhage.	• Patchy or diffuse GGO (Hemorrhage) • Cavitating nodules (GPA) • Septal thickening	Parenchyma / Vessels	Inflammation	Faces of Wegener’s Case 214Lu	Song
Asbestos-Related Pleural Disease	Pleural Disease	Pleural Plaques; BAPE	Definition: Non-malignant pleural manifestations of asbestos exposure. Comment: Plaques are the hallmark of exposure; BAPE is benign effusions.	• Calcified pleural plaques (Hallmark) • Diffuse pleural thickening • Round atelectasis (Comet tail)	Pleura	Inflammation	Faces of Plaques	Song
Asbestosis	Pneumoconiosis	Asbestos Pneumoconiosis	Definition: Chronic progressive interstitial fibrosis caused by heavy asbestos inhalation. Comment: Histology shows ferruginous bodies; Pattern mimics UIP.	• Basal predominant fibrosis (UIP pattern) • Subpleural curvilinear lines • Parenchymal bands	Interstitium (Parenchyma)	Inflammation	Faces of Asbestosis	Song
Aspiration Pneumonitis	Chemical lung injury	Mendelson’s Syndrome	Definition: Acute sterile injury from aspiration of acidic gastric contents. Comment: Occurs immediately post-event. No initial infection.	• Dependent GGO (Rapid onset) • Distribution: Posterior upper / Superior lower lobes • No cavitation	Dependent Alveoli	Inflammation	Faces of Aspiration	Song
Asthma	Obstructive Airway Disease	Reactive Airway Disease	Definition: Chronic inflammatory disorder of the airways characterized by reversible airflow obstruction and bronchial hyperresponsiveness. Comment: Imaging is often normal; CT is used to rule out mimics (e.g., tumor, ABPA) or complications.	• Normal (most common) • Bronchial wall thickening • Mosaic attenuation (air trapping on expiration)	Small Airways	Inflammation	Faces of Asthma Cases of Asthma	Song
Bronchiolitis (See Bronchiioltis Family Below)	Small Airway Inflammation	–	Definition: Inflammation of the bronchioles Comment: Please see the dedicated Bronchiiolitis Family table below for subtypes.	• Variable (See below)	Bronchi	Inflammation	Faces of Bronchiolitis Cases of Bronchiolitis
Bronchocentric Granulomatosis (BCG)	Granulomatous / Hypersensitivity	BCG	Definition: A necrotizing granulomatous inflammation centered on bronchi and bronchioles. Comment: ~50% associated with Asthma/ABPA; others associated with RA, Wegener’s, or idiopathic.	• Nodules/Masses: Spiculated, often upper lobe • Airway: Mucoid impaction / Atelectasis distal to lesion • Cavitation: Rare but possible	Bronchi / Bronchioles	Inflammation	Cases of Bronchocentric Granulomatosis	Song
Caplan Syndrome	Rheumatoid Lung	RA Pneumoconiosis	Definition: Pulmonary nodules in patients with RA and silica/coal exposure. Comment: Combined autoimmune and occupational pathology.	• Multiple rounded peripheral nodules • Background pneumoconiosis • May cavitate	Parenchymal nodules	Inflammation		Song
Cryptogenic Organizing Pneumonia (COP)	Organizing pneumonia	BOOP (historical)	Definition: Idiopathic inflammation with granulation tissue plugs in airways/alveoli. Comment: Classic presentation is flu-like illness with consolidation that improves with steroids.	• Patchy peripheral consolidation • Migratory opacities • Reverse Halo (Atoll) Sign	Alveoli / Small airways	Inflammation	Faces of Organizing Pneumonia Case 005Lu	Song look for AD art on OP
Desquamative Interstitial Pneumonia (DIP)	Smoking-related ILD	DIP	Definition: Smoking-related ILD with intra-alveolar macrophage accumulation. Comment: Good prognosis with smoking cessation.	• Diffuse GGO • Lower lobe predominance • Tiny cysts in GGO areas	Alveoli	Inflammation	Faces of DIP Case 252Lu	Song
Eosinophilic Pneumonia, Acute	Eosinophilic lung disease	Acute Eosinophilic Pneumonia (AEP)	Definition: Acute febrile illness with diffuse eosinophilic infiltration of the lungs, often in young adults with new smoking or inhalational exposure. Comment: Rapid onset hypoxemic respiratory failure; BAL eosinophilia is typical.	• Diffuse or patchy bilateral GGO • Smooth interlobular septal thickening • Pleural effusions common • Can mimic ARDS	Alveoli / Interstitium	Inflammation	Case 137Lu (AEP)	Song
Eosinophilic Pneumonia, Chronic	Eosinophilic lung disease	Chronic Eosinophilic Pneumonia (CEP)	Definition: Subacute to chronic eosinophilic infiltration of lung parenchyma, classically in middle-aged women with asthma. Comment: Relapsing course; excellent steroid response.	• Peripheral, upper-lobe predominant consolidation • “Photographic negative of pulmonary edema” pattern • GGO and band-like opacities • May be migratory	Alveoli / Interstitium			Song
Goodpasture Syndrome	Anti-GBM Disease	Anti-GBM	Definition: Autoantibodies against alveolar and glomerular basement membrane. Comment: Causes Diffuse Alveolar Hemorrhage (DAH) + rapidly progressive glomerulonephritis.	• Diffuse GGO (Hemorrhage) • Septal thickening • Rapid clearing (2–3 days)	Alveoli	Inflammation	Faces of DAH	Song
Hypersensitivity Pneumonitis (HP)	Inhalational Lung Disease	Extrinsic Allergic Alveolitis	Definition: Abrupt immune reaction hours after heavy antigen exposure. Comment: Presents as flu-like illness. Centrilobular GGO nodules.	• Centrilobular ground-glass nodules • Mosaic attenuation (Air trapping) • Headcheese sign (Chronic)	Secondary Lobule	Inflammation	Faces of HP Case 137Lu (AEP)	Art of HP Song
Hypersensitivity Pneumonitis, Acute	Inhalational Lung Disease	Acute Extrinsic Allergic Alveolitis	Definition: Acute flu-like illness occurring 4–12 hours after heavy antigen exposure. Comment: High reversibility with antigen avoidance.	• Diffuse or patchy GGO • Centrilobular nodules (soft/fluffy) • Mosaic attenuation (Air trapping)	Secondary Lobule	Inflammation		Song
Hypersensitivity Pneumonitis, Chronic	Inhalational Lung Disease	Fibrotic HP	Definition: Insidious onset of fibrosis due to prolonged low-level exposure. Comment: Poor prognosis if fibrosis is advanced; can mimic IPF.	• Headcheese Sign (Mixed density) • Reticulation & Fibrosis • Traction bronchiectasis • Spares costophrenic angles	Secondary Lobule / Interstitium	Inflammation / Fibrosis		Song neeed to clean up lyrics and add radiology
Langerhans Cell Histiocytosis (PLCH)	Smoking-related ILD	Histiocytosis X	Definition: Smoking-related cystic lung disease caused by proliferation of Langerhans cells. Comment: Cysts are often bizarrely shaped and spare the costophrenic angles.	• Bizarre shaped cysts (Upper lobe) • Nodules (early phase) • Spares costophrenic angles	Parenchyma	Inflammation	Faces of LCH Case 015Lu	Art of LCH Song
Lymphoid Interstitial Pneumonia (LIP)	Lymphoproliferative	LIP	Definition: Diffuse polyclonal lymphoid infiltration of the interstitium. Comment: Associated with Sjögren’s and HIV. Can progress to MALT Lymphoma.	• Thin-walled cysts (random) • Diffuse GGO • Centrilobular/Subpleural nodules	Interstitium	Inflammation	Faces of LIP Case 017Lu (HIV)	Art of LIP Song
NSIP (Nonspecific Interstitial Pneumonia)	CTD-ILD	NSIP	Definition: Chronic ILD with homogeneous inflammation/fibrosis. Comment: Common pattern in Scleroderma. Better prognosis than UIP.	• GGO + Reticulation • Subpleural sparing (Classic sign) • Lower lobe predominance	Interstitium	Inflammation	Faces of NSIP Case 110Lu (Scleroderma)	Art of NSIP Song
Organizing Pneumonia (OP)	Organizing pneumonia	Secondary OP	Definition: Histologic pattern of intra-alveolar granulation tissue (Masson bodies). Comment: Can be idiopathic (COP) or secondary to drugs, infection, or collagen vascular disease.	• Multifocal consolidation (Peribronchial/Subpleural) • Atoll sign (Reverse Halo) • Migratory opacities	Alveoli / Bronchioles	Inflammation	Faces of OP	Song see findings
Rheumatoid Lung Disease	CTD-ILD	RA-ILD	Definition: Pulmonary manifestations of Rheumatoid Arthritis. Comment: Can present as ILD (UIP/NSIP), nodules, or bronchiolitis.	• Pattern: UIP or NSIP • Nodules: Necrobiotic nodules • Airway: Bronchiolitis	Parenchyma / Pleura	Inflammation	Case 132Lu	Song
Sarcoidosis	Granulomatous	Sarcoid	Definition: Multisystem non-caseating granulomatous disorder. Comment: 90% have thoracic involvement.	• Perilymphatic nodules • Bilateral Hilar Adenopathy (Stage I) • Upper lobe fibrosis (Stage IV)	Interstitium / Nodes	Inflammation	Faces of Sarcoidosis Case 023Lu	Art of Sarcoidosis Song
Systemic Sclerosis (SSc-ILD)	CTD-ILD	Scleroderma Lung	Definition: Autoimmune fibrosis of skin and internal organs. Comment: Lung fibrosis is the leading cause of death. NSIP pattern most common.	• Basal-predominant GGO and reticulation • Esophageal dilation • Pulmonary Hypertension	Interstitium	Inflammation	Faces of Scleroderma Case 050Lu (NSIP)

Bronchiolitis Family Combination – Findings Inflamatory and Infectious Bronchiolitis

Disease / Diagnosis (Standard Link)	Grouped Category	Alternative Names	Definition & Comment	Imaging Features	Structure	Category	Faces & Cases	Case / Game Image
Bronchiolitis (General Pattern)	Overview	Small Airway Disease	Definition: Inflammation of the bronchioles (<2mm diameter) lacking cartilage. Comment: The pattern (cellular vs. constrictive) narrows the differential significantly.	• Direct: Centrilobular nodules, Tree-in-bud, Wall thickening • Indirect: Mosaic attenuation, Air trapping	Bronchioles	Inflammation	Faces of Bronchiolitis Cases of Bronchiolitis Cases of Bronchiolitis (Follicular) Obliterans
Bronchiolitis, Acute Infectious	Infection (Viral/Bacterial)	Infectious Bronchiolitis	Definition: Acute inflammation of bronchioles usually due to viral infection (RSV, Adenovirus, Influenza) or Mycoplasma. Comment: Common in children; in adults, implies aspiration or atypical infection.	• Tree-in-bud nodules (Impacted secretions) • Centrilobular soft tissue nodules • Air trapping	Bronchioles	Infection	Faces of Bronchiolitis Faces of Tree-in-Bud	Case 133Lu
Bronchiolitis, Constrictive	Fibrotic / Obstruction	Obliterative Bronchiolitis (OB); Bronchiolitis Obliterans	Definition: Submucosal fibrosis resulting in concentric narrowing and obliteration of the bronchiolar lumen. Comment: irreversible. Causes: Transplant (BOS), Toxic fumes (Popcorn lung), Post-viral, RA.	• Mosaic Attenuation (Hallmark) • Air trapping on expiratory CT • Normal or attenuated vessels in lucent lung	Bronchioles	Fibrosis	Faces of Bronchiolitis Cases of Bronchiolitis (Follicular) Obliterans
Diffuse Panbronchiolitis (DPB)	Idiopathic / Genetic	DPB	Definition: Idiopathic inflammatory disease of respiratory bronchioles predominantly affecting East Asians. Comment: Associated with HLA-B54 and chronic sinusitis. Responds to Macrolides.	• Diffuse centrilobular nodules • Bronchiectasis and Bronchiolectasis • Air trapping	Bronchioles	Inflammation	Faces of Bronchiolitis
Bronchiolitis, Follicular	Lymphoid Hyperplasia	BALT Hyperplasia	Definition: Hyperplasia of Bronchus-Associated Lymphoid Tissue (BALT) along the airways. Comment: Strongly associated with Collagen Vascular Diseases (RA, Sjögren’s) and Immunodeficiency.	• Small centrilobular nodules • Peribronchial nodules • Ground-glass attenuation	Bronchioles	Inflammation	Faces of Bronchiolitis
Bronchiolitis, Respiratory (RB-ILD)	Smoking-Related	Smoker’s Bronchiolitis	Definition: Accumulation of pigmented macrophages in respiratory bronchioles due to chronic smoking. Comment: The most common ILD in smokers. Usually asymptomatic or mild.	• Centrilobular micronodules (Upper lobe predominant) • Patchy Ground-Glass Opacity • Bronchial wall thickening	Bronchioles	Inflammation	Faces of Bronchiolitis

III Inflammation – Infection – Interface

Pneumonia Family

Disease / Diagnosis (Standard Link)	Grouped Category	Alternative Names	Definition & Comment	Imaging Features	Structure	Category	Faces & Cases	Art & Music	Case / Game Image
I. Infectious Pneumonias (Bacterial, Viral, Fungal)
Acute Bacterial Bronchopneumonia	Bacterial	Lobular Pneumonia	Definition: Infection centered on bronchioles spreading to adjacent alveoli (Staph, Strep, Haemophilus). Comment: Patchy distribution; common hospital-acquired pattern.	• Patchy, multifocal consolidation • Peribronchial nodules • Lower-lobe predominance	Bronchioles / Alveoli	Infection	Faces of Pneumonia
Acute Lobar Pneumonia	Bacterial	Pneumococcal Pneumonia	Definition: Rapid exudative edema of an entire lobe (Strep pneumoniae). Comment: The classic form of community-acquired pneumonia.	• Homogeneous lobar consolidation • Air bronchograms • Sharp fissural boundaries	Lobe	Infection	Faces of Pneumonia		RUL Consolidation (CT)
Aspiration Pneumonia	Bacterial (Anaerobic)	–	Definition: Infection following aspiration of oropharyngeal bacteria. Comment: Dependent distribution; risk of abscess.	• Dependent consolidation • Tree-in-bud nodules • Cavitation (late)	Dependent Lung	Infection	Faces of Aspiration		Case 136038
COVID-19 Pneumonia	Viral	SARS-CoV-2	Definition: Acute viral pneumonia causing diffuse alveolar damage. Comment: Peripheral GGO is the hallmark.	• Bilateral peripheral GGO • Crazy paving • Vascular dilation	Alveoli	Infection			Case 135L
Influenza Pneumonia	Viral	Flu	Definition: Seasonal viral infection. Comment: Risk of secondary bacterial superinfection.	• Poorly defined GGO • Peribronchovascular distribution • Patchy consolidation	Interstitium / Alveoli	Infection
Klebsiella Pneumonia	Bacterial (Necrotizing)	Friedländer Pneumonia	Definition: Severe necrotizing lobar pneumonia (alcoholics/diabetics). Comment: Heavy mucoid secretions cause volume expansion.	• Dense lobar consolidation • Bulging fissure sign • Abscess formation	Lobe	Infection	Faces of Pneumonia
Pneumocystis Pneumonia (PJP)	Fungal (Opportunistic)	PCP	Definition: Fungal infection in immunocompromised (HIV/Transplant). Comment: CD4 < 200.	• Diffuse/Perihilar GGO • Pneumatoceles (cysts) • Subpleural sparing	Interstitium	Infection			Case 163L
Staphylococcal Pneumonia	Bacterial (Necrotizing)	MRSA Pneumonia	Definition: Rapidly progressive necrotizing pneumonia. Comment: Common post-influenza; causes pneumatoceles in kids.	• Multifocal consolidation • Pneumatoceles (Cysts) • Cavitation	Parenchyma	Infection	Faces of Cavitating Pneumonia		Staph Case
Varicella Pneumonia	Viral	Chickenpox Lung	Definition: Pulmonary varicella infection (adults). Comment: Heals with calcifications.	• Multiple ill-defined nodules • Healed: Diffuse punctate calcifications	Parenchyma	Infection
II. Idiopathic Interstitial Pneumonias (Inflammatory / Fibrotic)
Acute Interstitial Pneumonia (AIP)	Diffuse Alveolar Damage	Hamman-Rich Syndrome	Definition: Rapidly progressive idiopathic DAD. Comment: Essentially “Idiopathic ARDS.”	• Diffuse GGO • Dependent consolidation • Traction bronchiectasis (late)	Alveoli / Interstitium	Inflammation
Cryptogenic Organizing Pneumonia (COP)	Organizing Pneumonia	BOOP (Historical)	Definition: Intra-alveolar granulation tissue plugs. Comment: Responds to steroids.	• Patchy peripheral consolidation • Reverse Halo (Atoll) Sign • Migratory opacities	Alveoli / Bronchioles	Inflammation	Faces of Organizing Pneumonia Case 005Lu
Desquamative Interstitial Pneumonia (DIP)	Smoking-Related	DIP	Definition: Intra-alveolar macrophage accumulation. Comment: Almost exclusive to smokers.	• Diffuse Ground-Glass Opacity • Lower lobe predominance • Tiny cysts within GGO	Alveoli	Inflammation	Faces of DIP Case 252Lu
Lymphoid Interstitial Pneumonia (LIP)	Lymphoproliferative	LIP	Definition: Polyclonal lymphoid infiltration. Comment: Associated with Sjögren’s and HIV.	• Thin-walled cysts (random) • Diffuse GGO • Centrilobular nodules	Interstitium	Inflammation	Faces of LIP Case 017Lu	Art of LIP
Nonspecific Interstitial Pneumonia (NSIP)	CTD-ILD	NSIP	Definition: Homogeneous inflammation/fibrosis. Comment: Common in Scleroderma/CTD.	• GGO + Reticulation • Subpleural sparing • Lower lobe predominance	Interstitium	Inflammation	Faces of NSIP Case 110Lu	Art of NSIP
UIP (Idiopathic Pulmonary Fibrosis)	Fibrotic	IPF / CFA	Definition: Progressive fibrosing pneumonia. Comment: UIP is the pattern; IPF is the disease.	• Honeycombing • Traction Bronchiectasis • Basal/Peripheral predominance	Interstitium	Fibrosis	Faces of UIP Case 083Lu	Art of Lobule
III. Eosinophilic Pneumonias
Acute Eosinophilic Pneumonia (AEP)	Eosinophilic	AEP	Definition: Acute febrile hypersensitivity reaction. Comment: Triggered by new smoking or dusts. Mimics ARDS/Pneumonia.	• Diffuse GGO • Smooth septal thickening • Pleural effusions	Alveoli / Interstitium	Inflammation	Case 137Lu
Chronic Eosinophilic Pneumonia (CEP)	Eosinophilic	CEP	Definition: Subacute eosinophilic infiltration. Comment: Middle-aged women with asthma.	• Peripheral consolidation • “Photographic negative of pulmonary edema” • Upper lobe predominance	Alveoli	Inflammation
IV. Aspiration / Chemical
Aspiration Pneumonitis	Chemical Injury	Mendelson’s Syndrome	Definition: Acute sterile chemical injury from acid aspiration. Comment: Immediate onset; no initial infection.	• Dependent GGO (rapid onset) • Posterior upper / Superior lower lobes	Alveoli	Injury	Faces of Aspiration
Lipoid Pneumonia	Exogenous Lipid	–	Definition: Chronic inflammation from aspiration of mineral oil/lipids. Comment: Chronic use of laxatives/lip balm.	• Low attenuation consolidation (Fat density -30 to -100 HU) • “Crazy paving” within consolidation	Alveoli	Foreign Body

III Infection – Bacterial

Disease / Diagnosis (Standard Link)	Grouped Category	Alternative Names	Definition & Comment	Imaging Features	Structure	Category	Faces & Cases	Case / Game Image
Acute Bacterial Bronchopneumonia	Typical bacterial pneumonia	Bronchopneumonia; Lobular pneumonia	Definition: Acute infection centered on bronchioles with spread to adjacent alveoli, often due to Staph/Strep. Comment: Common hospital-acquired pattern and post-viral superinfection.	• Patchy, multifocal peribronchial consolidation • Ill-defined nodular opacities • Lower-lobe / dependent predominance	Bronchioles	Infection (Bacterial)	1. Faces of Pneumonia
Acute Lobar Pneumonia (Pneumococcal)	Typical bacterial pneumonia	Pneumococcal pneumonia	Definition: Classically due to Streptococcus pneumoniae with abrupt onset of fever, cough, and pleuritic pain. Comment: Prototype of “classic” lobar pneumonia.	• Homogeneous lobar or segmental consolidation • Air bronchograms • Sharp fissural boundaries	Lobe / Segment	Infection (Bacterial)	1. Faces of Pneumonia	RUL Consolidation (CT)
Anaerobic Aspiration Pneumonia	Dependent aspiration pneumonia	Aspiration pneumonitis	Definition: Aspiration of oropharyngeal contents containing anaerobic bacteria in patients with impaired airway protection. Comment: Often subacute with foul sputum; high risk of cavitation and abscess.	• Dependent consolidation (posterior upper / superior lower lobes) • Tree-in-bud and centrilobular nodules • Cavitation and abscess formation (late)	Dependent lung	Infection (Bacterial)	1. Faces of Aspiration	136038 Aspiration (CT IF)
Anthrax (Inhalational)	Severe inhalational bacterial disease	Bacillus anthracis	Definition: Inhalation of anthrax spores causing hemorrhagic mediastinitis and sepsis. Comment: High-mortality, high-consequence infection (bioterrorism concern).	• Mediastinal widening from hemorrhagic lymphadenitis • Large pleural effusions • Parenchymal opacities often late	Mediastinum / Pleura	Infection (Bacterial)	1. Faces of Infection
Bacterial Lung Abscess	Suppurative cavitary pneumonia	Pulmonary abscess	Definition: Localized necrosis of lung parenchyma with cavity formation due to bacterial infection (often anaerobes, Staph). Comment: Frequently related to aspiration or post-obstructive infection.	• Thick-walled cavity with air–fluid level • Surrounding consolidation • Usually single lesion in dependent segments	Parenchyma	Infection (Bacterial)	Faces of Abscess Cases of Abscess
Bronchitis Acute	Large Airway Infection	Chest Cold	Definition: Self-limited inflammation of the large airways. Comment: Mostly viral (>90%), but can be bacterial (Mycoplasma, Bordetella). Main role of imaging is to exclude pneumonia.	• Normal CXR (Hallmark feature) • Bronchial wall thickening (Cuffing) • Absence of consolidation	Bronchi	Infection (Bacterial/Viral)	Faces of Bronchitis Cases of Bronchitis
Empyema	Complicated pleural bacterial infection	Suppurative pleuritis; Pyothorax	Definition: Purulent fluid collection in the pleural space, usually secondary to bacterial pneumonia or surgery. Comment: Represents the “complicated” end of parapneumonic effusions.	• Lenticular pleural collection • Split-pleura sign on contrast CT • Loculations and septations • Compressive atelectasis of adjacent lung	Pleural space	Infection (Bacterial)	1. Faces of Empyema	CT Empyema
Klebsiella Pneumonia	Severe necrotizing bacterial pneumonia	Friedländer pneumonia	Definition: Necrotizing lobar pneumonia, classically in alcoholics and diabetics, caused by Klebsiella pneumoniae. Comment: Characteristic “currant jelly” sputum and high risk for abscess.	• Dense lobar consolidation (often upper lobe) • Bulging fissure sign from volume expansion • Early cavitation and abscess formation	Upper lobe alveoli	Infection (Bacterial)	1. Faces of Pneumonia
Septic Pulmonary Emboli	Hematogenous septic embolic disease	Septic emboli	Definition: Embolization of infected thrombi to the pulmonary arteries (e.g., right-sided endocarditis, IV drug use). Comment: Often multifocal and cavitating; look for cardiac or catheter source.	• Multiple peripheral nodules, often wedge-shaped • Cavitation common • Feeding vessel sign (vessel leading to nodule)	Peripheral parenchyma	Infection (Bacterial)	1. Faces of Infection
Staphylococcal Pneumonia (Necrotizing)	Necrotizing bacterial pneumonia	Staphylococcus aureus pneumonia (often MRSA)	Definition: Severe, rapidly progressive pneumonia, often post-influenza, due to toxin-producing Staph aureus. Comment: High risk of respiratory failure and pneumatoceles in children.	• Multiple cavitating abscesses and pneumatoceles • Patchy or confluent consolidation • Surrounding ground-glass opacity	Parenchyma	Infection (Bacterial)	1. Faces of Cavitating Pneumonia	Staph Cavitating Pneumonia

Dedicated Mycobacterial

Disease / Diagnosis (Standard)	Grouped Category	Alternative Names	Definition & Comment	Imaging Features	Structure	Category	Faces & Cases (Links 2 & 3)
TB – Primary	Initial Infection	Childhood TB	Initial infection with M. tuberculosis. Often asymptomatic or mild flu-like illness.	• Consolidation: Middle/Lower lobe (Ghon focus) • Nodes: Hilar/Mediastinal adenopathy • Combination: Ranke Complex (calcified node + scar)	Parenchyma / Nodes	Infection	1. Primary TB
TB – Reactivation	Post-Primary	Adult Type TB	Reactivation of latent infection due to waning immunity. Highly contagious.	• Cavity: Thick-walled, upper-lobe predominant • Spread: Endobronchial “Tree-in-bud” • Nodule: Tuberculoma formation	Upper Lobes	Infection	1. Reactivation TB
TB – Cavitary	Morphologic Type	Open TB	High bacterial burden infection resulting in parenchymal necrosis and expulsion of material.	• Shape: Thick-walled cavity • Position: Apical / Posterior segments • Complication: Rasmussen Aneurysm / Fungus ball	Upper Lobes	Infection	1. Cavitary Lung Disease
TB – Endobronchial	Airway TB	Bronchial TB	Specific infection of the tracheobronchial mucosa causing stenosis or obstruction.	• Airway: Irregular narrowing / Stenosis • Distal: Lobar collapse or hyperinflation (ball-valve) • Sign: Tree-in-bud	Bronchi	Infection	1. Tuberculosis (Overview)
TB – Miliary	Disseminated	Hematogenous TB	Hematogenous spread causing severe systemic illness. “Millet seed” appearance.	• Size: Countless 1–3 mm nodules • Distribution: Random (diffuse) • Organs: Hepatosplenomegaly	Parenchyma	Infection	1. Miliary TB
TB – Pleural Effusion	Extrapulmonary	TB Pleuritis	Lymphocyte-predominant exudate caused by hypersensitivity to antigens.	• Fluid: Free-flowing or loculated • Pleura: Thickening and enhancement • Late: Fibrothorax (calcification)	Pleura	Infection	1. Pleural Effusion
TB – Pericarditis	Extrapulmonary	Tuberculous Pericarditis	Infection of the pericardial sac. Common cause of constriction in endemic areas.	• Effusion: Serosanguinous fluid • Calcification: Thickened “Armor Heart” • Function: Constrictive physiology	Pericardium	Infection	1. Pericarditis
TB – Lymphadenitis	Extrapulmonary	Scrofula (Neck)	Infection of lymph nodes. Characteristic of Primary TB.	• Enhancement: Peripheral rim-enhancement • Center: Hypodense (Necrotic/Caseous) • Location: Mediastinal / Hilar / Supraclavicular	Mediastinum	Infection	1. Mediastinal Lymphadenopathy
TB – Fibrotic Sequelae	Chronic/Healed	Old TB	Scarring resulting from healed infection. Volume loss and distortion.	• Position: Upper-lobe scarring (“Apical Cap”) • Volume: Retraction of hilum • Airway: Traction bronchiectasis	Upper Lobes	Infection	1. Apical Cap / Scarring
TB – Empyema	Complication	TB Pyothorax	Purulent infection of the pleural space. Risk of Bronchopleural Fistula.	• Pleura: Split pleura sign • Shape: Lenticular loculated fluid • Calcification: Calcified pleural rind (chronic)	Pleura	Infection	1. Empyema
NTM – MAC (Nodular)	Slow Grower	Lady Windermere	Mycobacterium Avium Complex in elderly women who suppress cough.	• Airway: Cylindrical bronchiectasis • Nodule: Tree-in-bud centrilobular nodules • Position: RML and Lingula predominance	RML / Lingula	Infection	1. 247Lu MAC Case
NTM – MAC (Fibrocavitary)	Slow Grower	Classic MAC	MAC infection resembling TB. Seen in older males with COPD.	• Cavity: Thin-walled upper lobe cavities • Pleura: Apical thickening • Note: Less pleural effusion than TB	Upper Lobes	Infection	1. NTM Overview
NTM – M. abscessus	Rapid Grower	M. abscessus	Highly resistant, rapid-growing mycobacterium. Severe disease in CF patients.	• Airway: Severe Bronchiectasis • Pattern: Tree-in-bud and nodules • Cavity: Thick-walled cavities	Bronchi / Bronchioles	Infection	1. NTM Overview
NTM – M. kansasii	Slow Grower	Yellow Bacillus	Clinical presentation very similar to Reactivation TB. Strong COPD association.	• Cavity: Thin-walled upper lobe cavities • Position: Apical/Posterior segments • Effusion: Rare	Upper Lobes	Infection	1. NTM Overview
NTM – M. fortuitum	Rapid Grower	M. fortuitum	Skin/Soft tissue pathogen that can cause pulmonary nodules/abscesses. Post-traumatic.	• Pattern: Patchy consolidation or nodules • History: Post-procedural or aspiration	Parenchyma	Infection
NTM – M. xenopi	Slow Grower	Hot Water Bacillus	Associated with hot water systems. Slow-growing cavitary disease.	• Cavity: Upper-lobe cavities • Nodule: Pulmonary nodules • Time: Indolent course	Upper Lobes	Infection
NTM – M. gordonae	Contaminant	Tap Water Bacillus	Usually a lab contaminant; rarely pathogenic in immunocompetent hosts.	• Imaging: Usually normal or unrelated changes • Diagnosis: Rule out contamination	N/A	Infection

Atypical Infections

Disease / Diagnosis (Standard Link)	Grouped Category	Alternative Names	Definition & Comment	Imaging Features	Structure	Category	Faces & Cases (Links 2 & 3)	Case / Game Image (Link 6)
Atypical Pneumonia (Acute) 1. Atypical Pneumonia Pneumonia Overview	General atypical pneumonia	Walking pneumonia	Definition: Non-specific atypical infection with mild systemic symptoms due to multiple organisms (Mycoplasma, Chlamydia, Viral). Comment: Classic “walking pneumonia” presentation; often subacute and under-recognized.	• Pattern: Ground-glass opacity (GGO) and patchy consolidation • Airway: Peribronchial thickening • Nodules: Scattered centrilobular nodules	Bronchi / Alveoli	Infection (Atypical)
Chlamydia pneumoniae	Atypical bacterial pneumonia	TWAR agent	Definition: Common community-acquired atypical pneumonia due to C. pneumoniae. Comment: Often mild “walking pneumonia” with persistent dry cough.	• Pattern: Patchy GGO and small foci of consolidation • Airway: Bronchial wall thickening • Mimic: Viral pneumonia	Bronchi / Alveoli	Infection (Atypical)	s
Chlamydia psittaci	Exotic atypical pneumonia	Psittacosis; Parrot fever	Definition: Zoonotic infection acquired from birds due to C. psittaci. Comment: More severe systemic illness than typical C. pneumoniae infection.	• Consolidation: Unilateral or bilateral “round pneumonia” opacities • GGO: Peripheral halo or surrounding haziness • Organ: Splenomegaly and hepatomegaly may be present	Alveoli	Infection (Atypical)
Coxiella burnetii (Q Fever)	Atypical zoonotic pneumonia	Q Fever	Definition: Highly infectious zoonosis (cattle, sheep, goats) caused by C. burnetii. Comment: Can cause hepatitis, fever, and atypical pneumonia.	• Opacity: Round or segmental airspace opacities • Pleura: Pleural effusion is uncommon (helps distinguish from typical bacterial pneumonia)	Alveoli	Infection (Atypical)
1. Legionella (Pneumonia)	Severe atypical pneumonia	Legionnaires’ disease	Definition: Waterborne inhalational infection by Legionella species. Comment: Severe, rapidly progressive pneumonia with systemic and GI symptoms, often in outbreaks.	• Consolidation: Multifocal, rapidly progressive airspace disease • GGO: Centrilobular nodules and GGO • Pleura: Pleural effusions common (unlike many other atypicals)	Alveoli	Infection (Atypical)
Mycoplasma pneumoniae 1. Infectious Bronchiolitis	Classic atypical pneumonia	Walking pneumonia	Definition: Common atypical pneumonia in young adults due to M. pneumoniae. Comment: Slow, insidious onset; may have prominent extrapulmonary manifestations.	• Airway: Bronchial wall thickening (“cuffing”) • Pattern: Tree-in-bud and centrilobular nodules • GGO: Patchy air-space opacity	Bronchioles	Infection (Atypical)		1. Bronchopneumonia DDx Game
Mycoplasma (Necrotizing) Necrotizing Pneumonia	Severe atypical pneumonia	Severe Mycoplasma	Definition: Uncommon severe variant of Mycoplasma pneumoniae infection. Comment: Can mimic bacterial necrotizing pneumonia with significant morbidity.	• Consolidation: Lobar or segmental, may be dense • Nodules: Extensive tree-in-bud and centrilobular nodules • Cavity: Rare cavitation possible in severe disease	Alveoli	Infection (Atypical)	1. nia
Ureaplasma Pneumonia	Opportunistic atypical	Ureaplasma	Definition: Opportunistic infection due to Ureaplasma species, particularly in immunosuppressed patients and neonates. Comment: Important cause of severe respiratory failure in premature newborns.	• Pattern: Diffuse or patchy GGO • Interstitium: Interstitial prominence/thickening	Interstitium	Infection (Atypical)	1. Diffuse GGO

Viral Infections

Disease / Diagnosis (Standard Link)	Grouped Category	Alternative Names	Definition & Comment	Imaging Features	Structure	Category	Case / Game Image (Link 6)
Adenovirus Pneumonia	Viral Pneumonia	–	Definition: DNA virus causing severe lower respiratory infection, often in military recruits or immunocompromised. Comment: Can be necrotizing; known to cause significant sequel of Swyer-James syndrome (post-infectious obliterative bronchiolitis).	• Pattern: Patchy consolidation or GGO • Sign: Lobar collapse is common • Chronic: Mosaic attenuation (air trapping)	Bronchi / Alveoli	Infection (Viral)
Bronchitis Acute	Large Airway Infection	Chest Cold	Definition: Self-limited inflammation of the large airways, predominantly caused by viruses (Influenza, Rhinovirus, etc.). Comment: Clinical diagnosis (cough 1-3 weeks); imaging is used primarily to exclude pneumonia.	• Normal CXR (Hallmark feature) • Bronchial wall thickening (Cuffing) • Absence of consolidation	Bronchi	Infection (Viral)
CMV Pneumonia	Opportunistic Viral	Cytomegalovirus	Definition: Serious viral pneumonitis in immunocompromised hosts (Transplant, HIV). Comment: Reactivation of latent virus is common.	• Pattern: Diffuse Ground-Glass Opacity • Nodules: Small centrilobular nodules • Mix: Often co-exists with PJP	Interstitium	Infection (Viral)
COVID-19 Pneumonia (Acute)	Viral Pneumonia	SARS-CoV-2	Definition: Acute phase viral pneumonia characterized by diffuse alveolar damage and microthrombosis. Comment: Peak injury usually occurs 10-12 days after symptom onset.	• Pattern: Peripheral, bilateral GGO • Sign: Crazy paving (GGO + septal thickening) • Vascular: Enlarged subsegmental vessels	Peripheral Alveoli	Infection (Viral)	Case 135L
COVID-19 (Post-Acute / Chronic)	Organizing / Fibrotic	Long COVID Lung	Definition: Persistence of respiratory symptoms and imaging abnormalities >4 weeks after acute infection. Comment: Represents Organizing Pneumonia (OP) or evolving fibrosis.	• Pattern: Perilobular opacities (Arcades) • Fibrosis: Traction bronchiectasis • Sign: Architectural distortion / Bands	Interstitium	Inflammation (Post-Viral)
Hantavirus Pulmonary Syndrome	Zoonotic Viral	Sin Nombre Virus	Definition: Severe, rapid-onset pulmonary edema caused by inhalation of rodent excreta. Comment: Distinct from other viral pneumonias; mimics cardiac edema or ARDS.	• Pattern: Rapidly progressive interstitial edema • Effusion: Pleural effusions (Common, unlike other viruses) • Heart: Normal heart size	Interstitium	Infection (Viral)
Influenza Pneumonia	Viral Pneumonia	Flu	Definition: Seasonal viral lower respiratory tract infection due to influenza A or B. Comment: Predisposes to secondary bacterial pneumonia (especially Staph aureus).	• Pattern: Poorly defined GGO or consolidation • Distribution: Peribronchovascular, patchy • Complication: Necrotizing bacterial superinfection	Bronchi / Alveoli	Infection (Viral)
Measles Pneumonia	Viral Pneumonia	Giant Cell Pneumonia	Definition: Severe pneumonia caused by Rubeola virus, often in unvaccinated or immunocompromised (Hecht’s pneumonia). Comment: Can occur years later as SSPE (CNS), but acute lung involvement is severe.	• Pattern: Diffuse reticulonodular opacities • Nodes: Hilar lymphadenopathy • Complication: Superinfection	Interstitium	Infection (Viral)
RSV Pneumonia / Bronchiolitis	Viral Bronchiolitis	Resp. Syncytial Virus	Definition: Major cause of lower respiratory infection in infants and increasingly recognized in elderly adults. Comment: Predominantly affects small airways (bronchioles) rather than alveoli.	• Airway: Bronchial wall thickening • Pattern: Tree-in-bud nodules • Sign: Air trapping / Hyperinflation	Small Airways	Infection (Viral)
Varicella Pneumonia	Viral Pneumonia	Chickenpox Lung	Definition: Pulmonary involvement of varicella (chickenpox), usually in adults or immunocompromised patients. Comment: Can leave characteristic diffuse calcified nodules as a healed phase.	• Acute: Numerous ill-defined 5–10 mm nodules • Healed: Diffuse punctate calcifications (“microlithiasis” appearance)	Parenchyma	Infection (Viral)

Aspergillus Family

Disease / Diagnosis (Standard Link)	Grouped Category	Alternative Names	Definition & Comment	Imaging Features	Structure	Category	Faces & Cases
Aspergillosis (General)	Fungal Spectrum	Aspergillosis	Definition: A spectrum of fungal diseases caused by Aspergillus species, ranging from allergic reactions to saprophytic colonization and invasive infection. Comment: The specific manifestation depends almost entirely on the patient’s immune status.	• Variable: See specific subtypes below • Key Signs: Finger-in-glove, Air crescent, Halo sign	Airways / Parenchyma	Infection (Fungal)	Faces of Aspergillus Infection
Aspergillosis (Acute Airway Invasive)	Invasive Mold	Aspergillus Bronchopneumonia	Definition: Invasion of airway basement membrane by fungi without vascular invasion. Seen in non-neutropenic hosts (e.g., post-Influenza, steroid use). Comment: Distinct from angioinvasive; resembles bacterial bronchopneumonia.	• Pattern: Centrilobular nodules & Tree-in-bud • Airway: Bronchial wall thickening • Consolidation: Peribronchial patches	Small Airways	Infection (Fungal)	1. Faces of Aspergillus Infection
Aspergillosis (Chronic)	Chronic Mold	CNPA / Semi-invasive	Definition: Subacute tissue invasion in mildly immunocompromised patients (e.g., COPD, Alcoholism, Diabetes). Comment: Progresses over 1-3 months; distinct from the rapid angioinvasive form.	• Consolidation: Slowly progressive consolidation • Cavity: Internal cavitation develops over time • Pleura: Adjacent pleural thickening	Parenchyma	Infection (Fungal)	1. Faces of Aspergillus Infection
Aspergillosis (Chronic Cavitary)	Chronic Mold	CCPA	Definition: Chronic fibrosing cavitary disease lasting >3 months. Usually in immunocompetent patients with prior lung damage (e.g., TB). Comment: Can contain fungus balls; can progress to fibrosis (CFPA).	• Cavity: Multiple thick-walled upper lobe cavities • Contents: May contain mobile debris/fungus balls • Pleura: Significant pleural fibrosis	Upper Lobes	Infection (Fungal)	1. Faces of Aspergillus Infection
ABPA (Allergic Aspergillosis)	Hypersensitivity	ABPA	Definition: Hypersensitivity reaction to Aspergillus in patients with Asthma or Cystic Fibrosis, characterized by elevated IgE and eosinophilia. Comment: Causes recurrent mucus plugging and central airway damage; can progress to bronchiectasis if untreated.	• Airway: Central bronchiectasis • Sign: Finger-in-glove high-density mucus • Pattern: Migratory opacities	Central Bronchi	Infection (Fungal)	Faces of ABPA Cases of ABPA
Aspergillosis (Angioinvasive)	Invasive Mold	IPA	Definition: Invasion of pulmonary blood vessels by Aspergillus in severely immunocompromised, often neutropenic, patients. Comment: High mortality; rapid CT changes can precede clinical deterioration.	• Sign: Halo sign (nodule with surrounding GGO, early phase) • Late: Air crescent sign during recovery/cavitation • Progression: Rapid enlargement, wedge-shaped infarcts	Vessels / Parenchyma	Infection (Fungal)	1. Faces of Aspergillus Infection
Aspergilloma	Saprophytic	Fungus Ball / Mycetoma	Definition: Colonization of a pre-existing pulmonary cavity (e.g., TB, Sarcoid) by Aspergillus without frank tissue invasion. Comment: Classically presents with hemoptysis in patients with chronic cavitary lung disease.	• Sign: Air crescent (Monod) sign • Motion: Fungus ball moves with patient position • Pleura: Adjacent pleural thickening	Cavity	Infection (Fungal)	1. Faces of Aspergillus Infection Cases of Aspergilloma aka Air Crescent Sign

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FFF Fungal Infections

Aspergillus Family

Disease / Diagnosis (Standard Link)	Grouped Category	Alternative Names	Definition & Comment	Imaging Features	Structure	Category	Faces & Cases (Links 2 & 3)
Aspergillosis Aspergillus Infection General	Fungal Spectrum	Aspergillosis	Definition: A spectrum of fungal diseases caused by Aspergillus species, ranging from allergic reactions to saprophytic colonization and invasive infection. Comment: The specific manifestation depends almost entirely on the patient’s immune status.	• Variable: See specific subtypes below • Key Signs: Finger-in-glove, Air crescent, Halo sign	Airways / Parenchyma	Infection (Fungal)	Faces of Aspergillus Infection
Aspergillosis (Acute Airway Invasive)	Invasive Mold	Aspergillus Bronchopneumonia	Definition: Invasion of airway basement membrane by fungi without vascular invasion. Seen in non-neutropenic hosts (e.g., post-Influenza, steroid use). Comment: Distinct from angioinvasive; resembles bacterial bronchopneumonia.	• Pattern: Centrilobular nodules & Tree-in-bud • Airway: Bronchial wall thickening • Consolidation: Peribronchial patches	Small Airways	Infection (Fungal)	1. Faces of Aspergillus Infection
Aspergillosis (Chronic )	Chronic Mold	CNPA / Semi-invasive	Definition: Subacute tissue invasion in mildly immunocompromised patients (e.g., COPD, Alcoholism, Diabetes). Comment: Progresses over 1-3 months; distinct from the rapid angioinvasive form.	• Consolidation: Slowly progressive consolidation • Cavity: Internal cavitation develops over time • Pleura: Adjacent pleural thickening	Parenchyma	Infection (Fungal)	1. Faces of Aspergillus Infection
Aspergillosis (Chronic Cavitary)	Chronic Mold	CCPA	Definition: Chronic fibrosing cavitary disease lasting >3 months. Usually in immunocompetent patients with prior lung damage (e.g., TB). Comment: Can contain fungus balls; can progress to fibrosis (CFPA).	• Cavity: Multiple thick-walled upper lobe cavities • Contents: May contain mobile debris/fungus balls • Pleura: Significant pleural fibrosis	Upper Lobes	Infection (Fungal)	1. Faces of Aspergillus Infection
ABPA (Allergic Aspergillosis)	Hypersensitivity	ABPA	Definition: Hypersensitivity reaction to Aspergillus in patients with Asthma or Cystic Fibrosis, characterized by elevated IgE and eosinophilia. Comment: Causes recurrent mucus plugging and central airway damage; can progress to bronchiectasis if untreated.	• Airway: Central bronchiectasis • Sign: Finger-in-glove high-density mucus • Pattern: Migratory opacities	Central Bronchi	Infection (Fungal)	Faces of ABPA Cases of ABPA
Aspergillosis (Angioinvasive)	Invasive Mold	IPA	Definition: Invasion of pulmonary blood vessels by Aspergillus in severely immunocompromised, often neutropenic, patients. Comment: High mortality; rapid CT changes can precede clinical deterioration.	• Sign: Halo sign (nodule with surrounding GGO, early phase) • Late: Air crescent sign during recovery/cavitation • Progression: Rapid enlargement, wedge-shaped infarcts	Vessels / Parenchyma	Infection (Fungal)	1. Faces of Aspergillus Infection
Aspergilloma	Saprophytic	Fungus Ball / Mycetoma	Definition: Colonization of a pre-existing pulmonary cavity (e.g., TB, Sarcoid) by Aspergillus without frank tissue invasion. Comment: Classically presents with hemoptysis in patients with chronic cavitary lung disease.	• Sign: Air crescent (Monod) sign • Motion: Fungus ball moves with patient position • Pleura: Adjacent pleural thickening	Cavity	Infection (Fungal)	1. Faces of Aspergillus Infection Cases of Aspergilloma aka Air Crescent Sign

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Aspergillus Family

Disease / Diagnosis (Standard Link)	Grouped Category	Alternative Names	Definition & Comment	Imaging Features	Structure	Category	Faces & Cases
Aspergillus Infection (General)	Fungal Spectrum	Aspergillosis	Definition: A spectrum of fungal diseases caused by Aspergillus species, ranging from allergic reactions to saprophytic colonization and invasive infection. Comment: The specific manifestation depends almost entirely on the patient’s immune status.	• Variable: See specific subtypes below • Key Signs: Finger-in-glove, Air crescent, Halo sign	Airways / Parenchyma	Infection (Fungal)	Faces of Aspergillus Infection
ABPA (Allergic Aspergillosis)	Hypersensitivity	ABPA	Definition: Hypersensitivity reaction to Aspergillus in patients with Asthma or Cystic Fibrosis, characterized by elevated IgE and eosinophilia. Comment: Causes recurrent mucus plugging and central airway damage; can progress to bronchiectasis if untreated.	• Airway: Central bronchiectasis • Sign: Finger-in-glove high-density mucus • Pattern: Migratory opacities	Central Bronchi	Infection (Fungal)	1. Faces of ABPA 2. Case 220Lu
Aspergilloma	Saprophytic	Fungus Ball / Mycetoma	Definition: Colonization of a pre-existing pulmonary cavity (e.g., TB, Sarcoid) by Aspergillus without frank tissue invasion. Comment: Classically presents with hemoptysis in patients with chronic cavitary lung disease.	• Sign: Air crescent (Monod) sign • Motion: Fungus ball moves with patient position • Pleura: Adjacent pleural thickening	Cavity	Infection (Fungal)	1. Faces of Aspergillus Infection Cases of Aspergilloma aka Air Crescent Sign
Aspergillosis (Angioinvasive)	Invasive Mold	IPA	Definition: Invasion of pulmonary blood vessels by Aspergillus in severely immunocompromised, often neutropenic, patients. Comment: High mortality; rapid CT changes can precede clinical deterioration.	• Sign: Halo sign (nodule with surrounding GGO, early phase) • Late: Air crescent sign during recovery/cavitation • Progression: Rapid enlargement, wedge-shaped infarcts	Vessels / Parenchyma	Infection (Fungal)	1. Faces of Aspergillus Infection
Aspergillosis (Chronic Cavitary)	Chronic Mold	CCPA	Definition: Slowly progressive cavitary pulmonary aspergillosis in mildly immunocompromised hosts (e.g., COPD, diabetes). Comment: Intermediate between simple aspergilloma and angioinvasive disease.	• Cavity: Multiple thick-walled upper lobe cavities • Time: Symptoms and imaging > 3 months • Pleura: Pleural thickening and fibrosis	Upper Lobes	Infection (Fungal)	1. Faces of Aspergillus Infection

Fungal Infections (Non-Aspergillus)

Disease / Diagnosis (Standard Link)	Grouped Category	Alternative Names	Definition & Comment	Imaging Features	Structure	Category	Case / Game Image (Link 6)
Blastomycosis	Endemic Mycosis	Chicago Disease	Definition: Systemic mycosis due to inhalation of Blastomyces spores in endemic regions (Mississippi/Ohio valleys, Great Lakes). Comment: Can mimic bacterial pneumonia or malignancy; may have skin and bone involvement.	• Mass: Mass-like consolidation (“pseudotumor”) • Pattern: Miliary or larger nodules • Extras: Associated skin/bone lesions	Parenchyma	Infection (Fungal)
Candidiasis	Opportunistic Yeast	Pulmonary Candida	Definition: Hematogenous pulmonary involvement by Candida, usually in the setting of disseminated candidemia and severe sepsis. Comment: True primary Candida pneumonia is rare; imaging findings are often non-specific.	• Pattern: Multiple small nodules • Sign: Possible halo sign from hemorrhage • Context: Indwelling lines, broad-spectrum antibiotics, neutropenia	Diffuse	Infection (Fungal)
Coccidioidomycosis	Endemic Mycosis	Valley Fever	Definition: Pulmonary infection with Coccidioides species, endemic to southwestern U.S. deserts. Comment: Can present as self-limited pneumonia, chronic cavitary disease, or disseminated infection.	• Nodule: Solitary or multiple pulmonary nodules • Cavity: Thin-walled cavities, often upper lobes • Nodes: Hilar/mediastinal adenopathy	Parenchyma / Nodes	Infection (Fungal)
Cryptococcosis	Opportunistic Yeast	Crypto	Definition: Pulmonary and CNS infection due to encapsulated yeast (Cryptococcus neoformans), particularly in HIV or transplant patients. Comment: Lung disease may be asymptomatic or present with nodules/masses.	• Nodules: Solitary or multiple nodules or masses • Cavity: Cavitation common in HIV • Nodes: Mediastinal/hilar lymphadenopathy	Parenchyma	Infection (Fungal)
Histoplasmosis (Acute)	Endemic Mycosis	Ohio Valley Fever	Definition: Acute pulmonary infection from inhalation of Histoplasma capsulatum (bird/bat droppings). Comment: Can mimic TB/rheumatologic disease; may evolve to chronic cavitary disease or leave calcified granulomas.	• Consolidation: Patchy airspace opacities • Nodes: Hilar/mediastinal adenopathy • Healed: “Buckshot” calcifications in lung and spleen	Parenchyma / Nodes	Infection (Fungal)
Mucormycosis	Invasive Mold	Zygomycosis	Definition: Highly aggressive angioinvasive fungal infection seen in diabetic ketoacidosis and profound immunosuppression. Comment: Rapidly progressive; often fatal without urgent treatment.	• Sign: Reverse halo sign (central GGO with peripheral consolidation) • Character: Central necrosis and infarction • Progression: Rapid cavitation and hemorrhage	Parenchyma	Infection (Fungal)
Pneumocystis (PJP)	Opportunistic Fungal	PCP	Definition: Fungal infection seen in AIDS (CD4 < 200), transplant patients, and those on high-dose steroids, causing diffuse alveolar injury. Comment: Classic cause of acute hypoxemic respiratory failure in HIV.	• Pattern: Diffuse or perihilar ground-glass opacity • Cyst: Pneumatoceles, often upper lobe predominant • Sign: Possible subpleural sparing and crazy paving	Interstitium	Infection (Fungal)	Case 163L (PJP CT)

Protozoal & Parasitic Infections

Disease / Diagnosis (Standard Link)	Grouped Category	Alternative Names	Definition & Comment	Imaging Features	Structure	Category
Amebic Lung Abscess	Parasitic Extension	Entamoeba histolytica	Definition: Pulmonary involvement secondary to hepatic amebiasis via transdiaphragmatic spread. Comment: Consider in endemic regions or in patients with known liver abscess and right-sided pleuro-pulmonary findings.	• Cavity: Thick-walled abscess in RLL • Pleura: Associated empyema or pleural reaction • Liver: Contiguous hepatic abscess abutting diaphragm	RLL Parenchyma	Infection (Parasitic)
Ascaris (Loeffler Syndrome)	Eosinophilic Lung	Loeffler’s	Definition: Transient eosinophilic pulmonary reaction to Ascaris larval migration through the lungs. Comment: Self-limited hypersensitivity response with peripheral eosinophilia.	• Opacity: Fleeting, migratory peripheral opacities • Pattern: Patchy ground-glass opacities • Time: Resolves spontaneously over days to weeks	Peripheral Lung	Infection (Parasitic)
Echinococcosis (Simple Cyst)	Cystic Disease	Hydatid Cyst	Definition: Pulmonary hydatid disease representing the larval stage of Echinococcus tapeworm; lung is second most common site after liver. Comment: Often asymptomatic until large; may be solitary or multiple.	• Cyst: Well-circumscribed, water-density mass • Wall: Thin, smooth wall • Location: Lower lobes in ~60% of cases	Parenchyma	Infection (Parasitic)
Echinococcosis (Ruptured)	Complicated Cyst	Ruptured Hydatid	Definition: Rupture of a pulmonary hydatid cyst into bronchial tree or pleural space, with risk of anaphylaxis and secondary infection. Comment: May present with cough of salty fluid, acute chest pain, or hydropneumothorax.	• Sign: Water-lily sign (floating membranes in cyst) • Fluid: Air–fluid level (“meniscus sign”) • Pleura: Possible hydropneumothorax or empyema	Parenchyma / Pleura	Infection (Parasitic)
Malaria (ARDS)	Protozoal ARDS	Falciparum Malaria	Definition: Severe complication of Plasmodium falciparum infection causing non-cardiogenic pulmonary edema and ARDS. Comment: High mortality; imaging overlaps with other causes of ARDS.	• Pattern: Diffuse bilateral ground-glass opacities • Septa: Superimposed interlobular septal thickening • Sign: Possible “white-out” lung in advanced ARDS	Alveoli (Diffuse)	Infection (Protozoal)
Paragonimiasis	Lung Fluke	Paragonimus westermani	Definition: Parasitic infection acquired from undercooked freshwater crab or crayfish; adult flukes reside in lung cysts. Comment: Classically associated with hemoptysis and chronic eosinophilic inflammation.	• Cavity: Thin-walled cavities or cystic lesions • Nodule: Subpleural or subfissural nodules • Pleura: Effusion or spontaneous pneumothorax	Parenchyma	Infection (Parasitic)
Schistosomiasis (PHTN)	Pulmonary Vascular	Schistosoma	Definition: Egg embolization to pulmonary circulation causing granulomatous vasculitis and pulmonary hypertension. Comment: Important cause of pulmonary arterial hypertension in endemic regions.	• Vessels: Enlarged central pulmonary arteries • Heart: Right ventricular hypertrophy and dilation • Pattern: Diffuse micronodules representing granulomas	Pulmonary Artery	Infection (Parasitic)
Strongyloides (Hyperinfection)	Hyperinfection Syndrome	Strongyloides stercoralis	Definition: Massive autoinfection in immunosuppressed patients (steroids, HTLV-1) leading to widespread larval migration and pulmonary involvement. Comment: Frequently associated with diffuse alveolar hemorrhage and septic complications.	• Pattern: Diffuse GGO with or without consolidation • Sign: Crazy paving from hemorrhage and edema • Clue: Larvae identifiable in sputum or BAL	Alveoli	Infection (Parasitic)
Toxocara (Visceral Larva Migrans)	Larval Granuloma	VLM	Definition: Hypersensitivity reaction to migrating dog or cat roundworm larvae with multi-organ involvement. Comment: Typically affects children with pica; pulmonary disease is part of systemic syndrome.	• Nodule: Ill-defined peripheral nodules or opacities • Pattern: Migratory infiltrates over time • Blood: Marked eosinophilia	Peripheral Parenchyma	Infection (Parasitic)
Toxoplasmosis	Opportunistic Protozoa	Toxo Pneumonia	Definition: Pulmonary involvement by Toxoplasma gondii, usually reactivation in advanced HIV or transplant recipients. Comment: CNS disease predominates, but lung findings may mimic PJP.	• Pattern: Bilateral ground-glass opacities • Nodules: Small centrilobular nodules possible • Mimic: Radiographically similar to Pneumocystis pneumonia	Alveoli	Infection (Protozoal)

MMM Malignant Neoplasms

Disease / Diagnosis (Standard Link)	Grouped Category	Alternative Names	Definition & Comment	Imaging Features	Structure	Category	Faces & Cases (Links 2 & 3)	Case / Game Image (Link 6)
Carcinoid, Atypical	Neuroendocrine	Atypical Carcinoid	Definition: Intermediate-grade neuroendocrine tumor with higher mitotic rate and necrosis than typical carcinoid. Comment: Greater propensity for nodal and distant metastases.	• Position: Peripheral > central • Character: Larger, heterogeneous mass • Nodes: Nodal metastases more frequent	Parenchyma	Neoplasm (Malignant)	1. Faces of Carcinoid Tumors
Carcinoid, Typical	Neuroendocrine	Typical Carcinoid	Definition: Low-grade neuroendocrine tumor arising from bronchial Kulchitsky cells. Comment: Generally good prognosis; can cause hemoptysis or obstruction.	• Position: Central endobronchial location • Character: “Iceberg” lesion (small intraluminal component with larger extraluminal mass) • Calcification: Focal or diffuse calcifications common	Bronchi	Neoplasm (Malignant)	1. Faces of Carcinoid Tumors	118L (Typical)
Carcinoma, Adenocarcinoma	Primary Lung Cancer (NSCLC)	Adeno	Definition: Malignant epithelial tumor with glandular differentiation and a peripheral predilection. Comment: Most common subtype of primary lung cancer; often presents as an incidental pulmonary nodule.	• Position: Peripheral mass or nodule • Character: Solid, subsolid, or ground-glass (lepidic growth) • Sign: Pleural retraction or “puckering” toward the lesion	Peripheral Parenchyma	Neoplasm (Malignant)	1. Faces of Adenocarcinoma	136730 Adeno (CT)
Carcinoma, Large Cell	Primary Lung Cancer (NSCLC)	LCC	Definition: Undifferentiated NSCLC lacking glandular or squamous features; diagnosis of exclusion. Comment: Often presents as a large peripheral mass with aggressive behavior.	• Position: Usually peripheral • Size: Often large mass (> 4 cm) • Character: Necrosis and hemorrhage common	Parenchyma	Neoplasm (Malignant)
Carcinoma, Small Cell	Neuroendocrine	SCLC / Oat Cell	Definition: High-grade neuroendocrine malignancy with rapid doubling time and early metastasis, strongly smoking-related. Comment: Frequently presents with bulky mediastinal disease and paraneoplastic syndromes.	• Position: Central / hilar mass • Nodes: Bulky mediastinal and hilar lymphadenopathy • Complication: SVC syndrome and airway compromise	Central Bronchi / Nodes	Neoplasm (Malignant)	1. Faces of Small Cell Carcinoma	48L (Massive Nodes)
Carcinoma, Squamous Cell	Primary Lung Cancer (NSCLC)	SCC	Definition: Malignant tumor arising from bronchial epithelium, strongly associated with cigarette smoking. Comment: Tends to be centrally located and frequently cavitates.	• Position: Central / hilar mass • Character: Cavitation with thick, irregular wall • Complication: Post-obstructive atelectasis (e.g., Golden S sign)	Central Bronchi	Neoplasm (Malignant)	1. Faces of Squamous Cell Carcinoma	124L (Cavitary)
Kaposi Sarcoma	Vascular Malignancy	KS	Definition: HHV-8–associated vascular tumor seen predominantly in AIDS patients. Comment: Often coexists with cutaneous and GI Kaposi lesions.	• Distribution: Peribronchovascular and interlobular septal thickening • Character: Flame-shaped or flame-like perihilar opacities • Nodes: Hemorrhagic lymphadenopathy and possible effusions	Interstitium	Neoplasm (Malignant)
Lymphoma, Primary	Hematologic	MALT Lymphoma	Definition: Rare extranodal lymphoma arising from bronchus-associated lymphoid tissue (BALT). Comment: Indolent course; may be incidentally detected on imaging.	• Pattern: Consolidation, mass-like opacities, or multiple nodules • Sign: Air bronchograms often preserved within consolidation • Course: Slow progression over time	Parenchyma	Neoplasm (Malignant)	1. Faces of Lymphoma
Mesothelioma	Pleural Malignancy	Malignant Mesothelioma	Definition: Malignancy arising from pleural mesothelial cells, strongly associated with asbestos exposure. Comment: Tends to encase the lung and invade chest wall and mediastinum.	• Pleura: Circumferential nodular pleural thickening (rind-like) • Fluid: Unilateral pleural effusion common • Sign: Mediastinal fixation and volume loss of affected hemithorax	Pleura	Neoplasm (Malignant)
Metastasis, Hematogenous	Secondary Tumor	Pulmonary Mets	Definition: Hematogenous spread of extrapulmonary malignancy (e.g., colon, kidney, breast, sarcoma) to the lungs. Comment: Most common malignant pulmonary neoplasm overall.	• Pattern: “Cannonball” large round nodules or innumerable miliary nodules • Distribution: Random, often lower-lobe or peripheral predominance • Vessels: Feeding-vessel sign may be present	Parenchyma	Neoplasm (Malignant)	1. Faces of Metastases	77L (Cannonball)
Metastasis, Lymphangitic	Secondary Tumor	Lymphangitis Carcinomatosa	Definition: Tumor spread via lymphatic channels of the lung (often from breast, stomach, or lung primaries). Comment: Frequently presents with progressive dyspnea and relatively normal radiographs early.	• Septa: Nodular or beaded interlobular septal thickening • Fissures: Thickened, sometimes nodular fissures • Nodes: Hilar and mediastinal lymphadenopathy	Interstitium / Lymphatics	Neoplasm (Malignant)	1. Faces of Lymphangitis Carcinomatosis
Pancoast Tumor	Specific Presentation	Superior Sulcus Tumor	Definition: Lung cancer (usually squamous or adenocarcinoma) arising in the lung apex and invading the thoracic inlet structures. Comment: Classically associated with shoulder pain and Horner syndrome.	• Position: Apical lung mass in superior sulcus • Invasion: Rib destruction, chest wall and brachial plexus involvement • Nerves: Sympathetic chain involvement → Horner’s syndrome	Apical Lung / Chest Wall	Neoplasm (Malignant)

MMM Malignant Cancer Family
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Cancer Family

Disease / Diagnosis (Standard Link)	Grouped Category	Alternative Names	Definition & Comment	Imaging Features	Structure	Category	Faces & Cases	Art & Music
Cancer (General Overview)	Malignancy	Lung Carcinoma	Definition: Malignant neoplasm arising from lung epithelium. Comment: Leading cause of cancer death.	• Nodule (>3cm = Mass) • Spiculated margins • Calcification (eccentric/stippled)	Parenchyma / Airway	Neoplasm	Faces of Cancer Cancer Cases Faces: Consolidation Faces: Cancer & Time Faces: Position Faces: Cystic Lesions	Art of Lung Cancer
Adenocarcinoma	Non-Small Cell (NSCLC)	Adeno	Definition: Malignancy with glandular differentiation. Most common type in non-smokers. Comment: Peripheral location typical.	• Peripheral nodule/mass • Ground-glass (Lepidic) • Spiculation	Parenchyma (Peripheral)	Neoplasm	Faces of Adenocarcinoma Cases: 011Lu Mucinous 77Lu Mucinous (Neg FDG) 80Lu LCH + Adeno 211Lu Huge Necrotic Mass 286Lu Pneumonia/Lymphangitis
Adenocarcinoma (Lepidic Growth)	Non-Small Cell (NSCLC)	BAC (Historical)	Definition: Tumor growth along alveolar walls without invasion (in pure form). Comment: Presents as persistent Ground-Glass Opacity (GGO).	• Persistent GGO • “Fried Egg” appearance (part-solid) • Air bronchograms	Alveoli	Neoplasm	Cases of Lepidic Growth: 081Lu Lepidic 87Lu Lepidic 093Lu + Immunotherapy 139Lu ILD Mimic 230Lu Recurrence
Squamous Cell Carcinoma	Non-Small Cell (NSCLC)	SCC	Definition: Malignancy arising from bronchial epithelium. Strongly smoking-associated. Comment: Central location; tends to cavitate.	• Central hilar mass • Cavitation (thick-walled) • Atelectasis (obstructive)	Central Airways	Neoplasm	Faces of Squamous Cell Cases: 115Lu Central + SVC 152Lu Luftsichel 212Lu Obstructing + Collapse 229Lu Cryoablation 233Lu Pseudocavitation 239Lu + LUL Atelectasis 267Lu ABPA Masquerade 188Lu + SVC Syndrome
Small Cell Carcinoma	Neuroendocrine	SCLC; Oat Cell	Definition: Aggressive neuroendocrine tumor; early metastasis. Comment: Considered systemic at diagnosis. Central location.	• Massive hilar/mediastinal adenopathy • Direct mediastinal invasion • SVC syndrome	Central Airways / Nodes	Neoplasm	Faces of Small Cell Cases: 297Lu Small Cell 298Lu “White Out”
Cystic Lung Cancer	Atypical Presentation	–	Definition: Lung cancers presenting as cystic lesions or developing from bullae. Comment: Often Adenocarcinoma. Can mimic benign cysts or infection.	• Thick or irregular wall • Mural nodule • Septations	Parenchyma	Neoplasm	Faces of Cystic Lesions 109Lu Cystic Adeno 234Lu Cystic + Lepidic
Lymphangitis Carcinomatosa	Metastatic Pattern	–	Definition: Tumor spread through the pulmonary lymphatics. Comment: Adenocarcinoma (Breast, Lung, Stomach) is the most common cause.	• Smooth or nodular septal thickening • Peribronchial cuffing • Normal architecture preserved	Lymphatics / Interstitium	Metastasis	Faces of Lymphangitis Cases: 248Lu NSCLC 158Lu Adeno + Lymphangitis
Carcinoid Tumor	Neuroendocrine	Typical / Atypical Carcinoid	Definition: Low-grade neuroendocrine malignancy. Comment: Typical (indolent) vs. Atypical (aggressive). Often central endobronchial.	• Endobronchial nodule (Iceberg sign) • Intense contrast enhancement • Distal air trapping	Bronchi	Neoplasm	201Lu Carcinoid & Tumorlets
Atypical Adenomatoid Hyperplasia (AAH)	Precursor Lesion	AAH	Definition: Pre-invasive lesion for Adenocarcinoma. Comment: Usually <5mm.	• Small, faint Ground-Glass Nodule • No solid component	Alveoli	Pre-Neoplasm	203Lu AAH
Other / Unknown Type Cases	General	–	Definition: Cases demonstrating specific complications or presentations where cell type is secondary or unknown.	• Variable	Variable	Neoplasm	002Lu Screening 013Lu Rapid H&N Mets 67Lu Pneumonic Infiltrate 104Lu Total Atelectasis 105Lu Post-Bronch 120Lu LUL Collapse (Luftsichel) 127Lu COPD Atypical 155Lu Sarcoid Masquerade 237Lu RUL Bronchus CA

Malignant Neoplasm – Infiltrative Type

Disease / Diagnosis (Standard Link)	Grouped Category	Alternative Names	Definition & Comment	Imaging Features	Structure	Category
Angiosarcoma (Metastatic)	Vascular Malignancy	Metastatic Angiosarcoma	Definition: Highly vascular sarcoma metastasizing to lung. Comment: Often hemorrhagic. Primary sites include heart, breast, or scalp.	• Nodule: Multiple nodules with Halo Sign (Hemorrhage) • Pattern: Diffuse alveolar hemorrhage • Pleura: Hemothorax	Parenchyma	Infiltrative (Malignant)
Kaposi Sarcoma	Vascular Malignancy	KS	Definition: HHV-8 associated vascular tumor in AIDS/Transplant patients. Comment: Involves skin, GI tract, and lungs.	• Distribution: Peribronchovascular thickening • Character: “Flame-shaped” opacities • Nodes: Hemorrhagic adenopathy (Hyperattenuating)	Interstitium	Infiltrative (Malignant)
Leukemia (Infiltrates)	Hematologic Malignancy	Leukostasis	Definition: Infiltration of lung by circulating leukemic blasts. Comment: Seen in acute leukemias with very high WBC counts (Blast crisis).	• Pattern: Diffuse Ground-Glass Opacity • Septa: Smooth septal thickening (mimics edema) • Vessels: Peribronchovascular cuffing	Interstitium	Infiltrative (Malignant)
Lymphangitic Carcinomatosis	Lymphatic Spread	Lymphangitic Spread	Definition: Tumor spread along pulmonary lymphatic vessels. Comment: Common primaries: Breast, Stomach, Pancreas, Lung.	• Septa: Nodular/Beaded interlobular septal thickening • Fissure: Nodular fissural thickening • Symmetry: Often asymmetric/unilateral	Interstitium / Lymphatics	Infiltrative (Malignant)
Lymphoma (Primary MALT)	Hematologic Malignancy	MALT Lymphoma	Definition: Low-grade B-cell lymphoma arising from BALT (Bronchus-Associated Lymphoid Tissue). Comment: Indolent course. Associated with chronic inflammation/Sjögren’s.	• Pattern: Consolidation or Mass • Sign: Air Bronchogram (patent airways) • Distribution: Peribronchial	Parenchyma	Infiltrative (Malignant)
Lymphoma (Secondary)	Hematologic Malignancy	Secondary Lung Lymphoma	Definition: Pulmonary involvement by systemic Hodgkin or Non-Hodgkin Lymphoma. Comment: More common than primary lymphoma.	• Nodules: Multiple masses/nodules • Spread: Lymphangitic pattern • Nodes: Associated mediastinal adenopathy	Parenchyma / Nodes	Infiltrative (Malignant)
Myeloma (Plasmacytoma)	Plasma Cell Neoplasm	Extramedullary Plasmacytoma	Definition: Clonal plasma cell proliferation involving lung or pleura. Comment: Rare. Seen in Multiple Myeloma.	• Mass: Homogeneous mass/nodule • Bone: Associated lytic rib lesions	Parenchyma / Chest Wall	Infiltrative (Malignant)
Tumor Microemboli (PTTM)	Vascular Malignancy	PTTM	Definition: Pulmonary Tumor Thrombotic Microangiopathy—microscopic tumor emboli in small pulmonary arteries/arterioles. Comment: Causes severe pulmonary hypertension and acute cor pulmonale. Gastric and breast carcinomas are common primaries.	• Pattern: Tree-in-bud–like vascular pattern • Signs: Septal thickening and imaging signs of PHTN • Note: No large pulmonary embolus visible	Arterioles	Infiltrative (Malignant)

BBB Benign Neoplasms

Disease / Diagnosis	Grouped Category	Alternative Names	Definition	Imaging Features	Structure	Category	Faces & Case	Case Game Image
Adenoma, Alveolar	Epithelial	Alveolar Adenoma	Rare benign tumor arising from alveolar epithelium. Usually an incidental solitary nodule.	• Shape: Round/ovoid nodule • Position: Peripheral/subpleural • Density: Homogeneous soft tissue	Peripheral Lung	Neoplasm (Benign)
Adenoma, Bronchial Mucous	Epithelial	Mucous Gland Adenoma	Rare benign endobronchial tumor arising from mucous glands. Presents with obstruction or pneumonia.	• Position: Endobronchial polypoid mass • Effect: Distal air trapping or atelectasis • Airway: Air meniscus sign	Central Bronchi	Neoplasm (Benign)
Atypical Adenomatoid Hyperplasia Atypical	Epithelial Proliferation	Atypical Adenomatoid Lesion	Benign proliferative lesion with gland-like structures that may mimic low-grade malignancy.	• Shape: Well-circumscribed nodule • Density: Soft tissue • Behavior: No invasion or aggressive features	Parenchyma	Neoplasm (Benign)	Cases of Atypical Adenomatoid Hyperplasia
Calcified Nodule	Non-Neoplastic	Healed Granuloma	Focal healed inflammation (TB/Fungal). Included in differential of benign nodules.	• Calcification: Central, laminated, or diffuse • Stability: Unchanged over years • Margins: Smooth, sharp	Parenchyma	Neoplasm (Benign)
Hamartoma	Mesenchymal	Chondromatous Hamartoma	Most common benign lung tumor. Disorganized mixture of cartilage, fat, and connective tissue.	• Calcification: “Popcorn” pattern • Density: Intralesional fat • Margins: Smooth, well-circumscribed	Parenchyma	Neoplasm (Benign)		Case 41L (Hamartoma)
Lipoma, Endobronchial	Adipocytic	Bronchial Lipoma	Benign tumor of mature fat arising from submucosa. Causes airway obstruction.	• Density: Fat attenuation (-100 HU) • Position: Central airway mass • Effect: Distal collapse	Central Bronchi	Neoplasm (Benign)
Lipoma, Pleural	Adipocytic	Pleural Lipoma	Benign fatty tumor of parietal or mediastinal pleura.	• Density: Fat attenuation • Shape: Smooth, pleural-based • Angle: Obtuse chest-wall angles	Pleura	Neoplasm (Benign)
Papilloma, Squamous	Epithelial	Endobronchial Papilloma	Benign papillomatous proliferation; HPV-related. May be solitary or multiple.	• Position: Central airway polyp • Multiplicity: Multiple in papillomatosis • Cavity: May cavitate	Bronchi
Sclerosing Pneumocytoma	Epithelial	Sclerosing Hemangioma	Uncommon benign tumor of primitive respiratory epithelium. Female predominance.	• Enhancement: Avid • Shape: Round, well-defined • Sign: Air meniscus	Parenchyma	Neoplasm (Benign)		Case 242L
Solitary Fibrous Tumor (Benign)	Mesenchymal	Benign SFT	Pleural neoplasm attached by a pedicle. Previously called “Benign Mesothelioma.”	• Position: Pleural-based mass • Motion: Moves with position (pedunculated) • Contrast: Heterogeneous enhancement	Pleura

MMM Mechanical Disorders of the Lung

Disease / Diagnosis	Grouped Category	Alternative Names	Definition	Imaging Features	Structure	Category	Faces & Case	Art & Music	Case Game Image
Aspiration	Obstruction	Aspiration Pneumonitis	Definition: Entry of gastric/oral contents into airway. Comment: Chemical pneumonitis or obstruction.	• Dependent segment involvement • Tree-in-bud or consolidation	Dependent Airways	Mechanical			136038 Aspiration
Atelectasis, Band-like	Collapse	Plate Atelectasis	Definition: Thin subsegmental collapse. Comment: Hypoventilation/post-op.	• Linear basal opacity • Parallel to diaphragm	Subsegment	Mechanical			136438 Linear
Atelectasis, Cicatricial	Collapse	Fibrotic Collapse	Definition: Irreversible fibrosis-related volume loss. Comment: TB, sarcoid, radiation.	• Architectural distortion • Traction bronchiectasis • Permanent volume loss	Fibrotic Lung	Mechanical			136598 Cicatricial
Atelectasis, Compressive	Collapse	Passive Atelectasis	Definition: Collapse from external mass/effusion. Comment: Reversible.	• Adjacent to mass/effusion • Patent air bronchograms	Subpleural Lung	Mechanical			315271 Compressive
Atelectasis, Lobar	Collapse	Lobar Collapse	Definition: Collapse of entire lobe due to obstruction. Comment: Golden S sign → central mass.	• Fissure displacement • Hilar shift / elevated diaphragm	Lobe	Mechanical
Atelectasis, Rounded	Collapse	Folded Lung	Definition: Mass-like collapsed lung from pleural disease. Comment: Asbestos classic cause.	• Comet tail sign • Adjacent pleural thickening	Subpleural	Mechanical			118433 Rounded
Atelectasis, Total Lung	Collapse	Lung Collapse	Definition: Complete lung collapse. Comment: Obstruction vs massive effusion.	• Mediastinal shift (to / away) • White-out hemithorax	Entire Lung	Mechanical			118467 Total Lung
Bronchiolectasis (Traction)	Fibrotic Traction	Traction Bronchiolectasis	Definition: Irreversible dilation of bronchioles due to surrounding fibrosis. Comment: Hallmark sign of pulmonary fibrosis (UIP, NSIP).	• Dilated small airways within fibrosis • “Corkscrew” appearance peripherally • Associated with honeycombing/reticulation	Bronchioles	Mechanical (Traction)	Faces of Bronchiolectasis Cases of Bronchiolectasis
Bronchopulmonary Dysplasia (BPD)	Neonatal / Chronic Lung Disease	Chronic Lung Disease of Infancy	Definition: Chronic lung disease in premature infants treated with O2 and mechanical ventilation. Comment: Arrested alveolar development and fibrosis.	• Coarse reticular opacities • Cystic changes / bubbly appearance • Hyperinflation	Alveoli / Interstitium	Mechanical / Developmental	Faces of Bronchopulmonary Dysplasia Cases of Bronchopulmonary Dysplasia		048lu BPD
Bullous Lung Disease	Airspace Enlargement	Bullous Emphysema	Definition: Airspace >1cm in diameter with a thin wall (<1mm). Comment: “Giant Bulla” if >1/3 of hemithorax. Compression of adjacent lung.	• Large thin-walled airspaces • Paucity of vascular markings • Compression of adjacent parenchyma	Parenchyma	Mechanical / Structural	Faces of Bullous Lung Disease Cases of Bullous Lung Disease	Art / Music of Bulla	102lu Bulla (Masquerade)
Foreign Body Aspiration	Obstruction	FB Aspiration	Definition: Endobronchial obstruction from aspirated object. Comment: Ball-valve air trapping.	• Radiopaque FB if metallic • Distal hyperinflation or collapse	Bronchus	Mechanical
Hernia, Bochdalek	Diaphragmatic Defect	Posterolateral Hernia	Definition: Congenital posterolateral defect. Comment: Left > Right.	• Posterior–lateral location • Fat or bowel in thorax	Diaphragm	Mechanical
Hernia, Hiatal	Diaphragmatic Defect	Hiatus Hernia	Definition: Stomach herniation through hiatus. Comment: Retrocardiac mass with air-fluid level.	• Retrocardiac mass • Air–fluid level	Mediastinum	Mechanical			Hiatal Hernia Game
Hernia, Morgagni	Diaphragmatic Defect	Retrosternal Hernia	Definition: Anterior parasternal defect. Comment: Usually right side.	• Right cardiophrenic angle mass • Omentum/colon in hernia	Diaphragm	Mechanical
Hydropneumothorax	Air Leak	Hydro-PTX	Definition: Air + fluid in pleural space. Comment: Trauma, fistula, esophageal rupture.	• Straight air–fluid level • Underlying lung collapse • Visible air–fluid interface	Pleural Space	Mechanical			118467 HydroPTX
Pneumomediastinum	Air Leak	Mediastinal Emphysema	Definition: Free air in mediastinum. Comment: Macklin effect; consider Boerhaave.	• Continuous diaphragm sign • Lucent streaks around heart/vessels • Often extends to neck/subcutaneous emphysema	Mediastinum	Mechanical			Pneumomediastinum Game
Pneumothorax (Simple)	Air Leak	PTX	Definition: Air in pleural space without tension. Comment: Spontaneous or traumatic.	• Visceral pleural line • No lung markings peripherally • No mediastinal shift	Pleural Space	Mechanical
Pneumothorax (Tension)	Air Leak	Tension PTX	Definition: Rising pleural pressure causing hemodynamic instability. Comment: Life-threatening.	• Mediastinal shift away • Flattened / inverted diaphragm • Widened intercostal spaces	Pleural Space	Mechanical
Tracheobronchomalacia	Dynamic Collapse	TBM	Definition: Weak airway wall → expiratory collapse. Comment: Diagnosed on expiratory CT.	• >50% expiratory narrowing • Crescentic “frown” airway shape	Trachea	Mechanical

Aspiration Family

Disease / Diagnosis (Standard Link)	Grouped Category	Alternative Names	Definition & Comment	Imaging Features	Structure	Category	Faces & Cases (Links 2 & 3)	Case / Game Image (Link 6)
Aspiration General	Overview	Aspiration Syndromes	Definition: The inhalation of oropharyngeal or gastric contents into the lower respiratory tract. Manifestations depend on the nature of the material (acid, bacteria, solid) and host defense. Comment: A spectrum of disease ranging from acute chemical injury to chronic infection.	• Pattern: Dependent consolidation or GGO • Location: Posterior upper lobes / Superior lower lobes • Airway: Tree-in-bud (if infectious)	Airways / Alveoli	Injury / Infection	Faces of Aspiration Aspiration Cases
Aspiration Pneumonitis	Chemical Lung Injury	Mendelson’s Syndrome	Definition: Acute sterile inflammatory injury from aspiration of acidic gastric contents. Comment: Rapid onset after event (vomiting, anesthesia). Initially non-infectious.	• Dependent GGO (rapid onset) • Posterior upper / superior lower lobes • No cavitation unless infected	Dependent Alveoli	Inflammation	Faces of Aspiration
Aspiration Pneumonia	Dependent Bacterial	Anaerobic Pneumonia	Definition: Bacterial infection after aspiration of oropharyngeal contents. Comment: Seen in dysphagia, impaired consciousness.	• Dependent consolidation • Tree-in-bud / centrilobular nodules • Right-sided predominance	Dependent Segments	Infection	Faces of Aspiration	Case 136038 Aspiration
Aspiration (Necrotizing)	Necrotizing Bacterial	Necrotizing Pneumonia	Definition: Severe aspiration pneumonia with parenchymal necrosis. Comment: Classically anaerobic; alcoholism and poor dentition are risks.	• Multiple small cavities • Irregular lucencies • May progress to abscess	Alveoli (Necrotic)	Infection
Aspiration (Foreign Body)	Obstruction	FB Aspiration	Definition: Endobronchial obstruction by aspirated object. Comment: “Ball-valve” hyperinflation when partial; collapse when complete.	• Radiopaque FB if metallic • Distal hyperinflation (check-valve) • Collapse if complete obstruction	Bronchus	Mechanical

end

Aspiration Family

Disease / Diagnosis	Grouped Category	Alternative Names	Definition	Imaging Features	Structure	Category	Case Game Image
Aspiration Pneumonitis	Chemical Lung Injury	Mendelson’s Syndrome	Definition: Acute sterile inflammatory injury from aspiration of acidic gastric contents. Comment: Rapid onset after event (vomiting, anesthesia). Initially non-infectious.	• Dependent GGO (rapid onset) • Posterior upper / superior lower lobes • No cavitation unless infected	Dependent Alveoli	Inflammation
Aspiration Pneumonia	Dependent Bacterial	Anaerobic Pneumonia	Definition: Bacterial infection after aspiration of oropharyngeal contents. Comment: Seen in dysphagia, impaired consciousness.	• Dependent consolidation • Tree-in-bud / centrilobular nodules • Right-sided predominance	Dependent Segments	Infection	136038 Aspiration
Aspiration (Necrotizing)	Necrotizing Bacterial	Necrotizing Pneumonia	Definition: Severe aspiration pneumonia with parenchymal necrosis. Comment: Classically anaerobic; alcoholism and poor dentition are risks.	• Multiple small cavities • Irregular lucencies • May progress to abscess	Alveoli (Necrotic)	Infection
Aspiration Foreign Body	Obstruction	FB Aspiration	Definition: Endobronchial obstruction by aspirated object. Comment: “Ball-valve” hyperinflation when partial; collapse when complete.	• Radiopaque FB if metallic • Distal hyperinflation (check-valve) • Collapse if complete obstruction	Bronchus	Mechanical
Lung Abscess (Aspiration)	Suppurative Cavitary	Anaerobic Abscess	Definition: Cavitary infection secondary to severe aspiration. Comment: Polymicrobial; slow resolution typical.	• Thick-walled cavity • Air-fluid level • Surrounding consolidation	Parenchyma (Cavity)	Infection

TTT Trauma

Disease / Diagnosis	Grouped Category	Alternative Names	Definition & Comment	Imaging Features	Structure	Category	Case Game Image
Aortic Transection	Vascular Injury	Traumatic Aortic Injury	Definition: Aortic wall injury from rapid deceleration (blunt trauma). Comment: Classically at aortic isthmus (ligamentum arteriosum). High mortality.	• Direct: Pseudoaneurysm / Intimal flap / Contour abnormality • Indirect: Mediastinal hematoma / Apical cap	Aorta (Isthmus)	Trauma
Lung Contusion	Parenchymal Injury	Pulmonary Contusion	Definition: Alveolar hemorrhage and edema without laceration. Comment: Most common lung injury. Appears within hours, resolves in days.	• Pattern: Patchy, non-segmental consolidation • Location: Adjacent to impact or fracture (coup/contrecoup)	Alveoli	Trauma
Lung Laceration	Parenchymal Injury	Traumatic Pneumatocele	Definition: Traumatic tear of lung parenchyma. Comment: Creates a cavity that fills with air (pneumatocele), blood (hematoma), or both.	• Shape: Round/ovoid cavity • Content: Air-fluid level (hematopneumatocele) • Surround: Contusion	Parenchyma	Trauma
Lung Hematoma	Parenchymal Injury	Intraparenchymal Hematoma	Definition: Localized collection of blood within the lung. Comment: Often results from a laceration filling with blood. Resolves slowly (months).	• Shape: Round, high-density mass • Evolution: Density decreases over time • Mimic: Pulmonary nodule/mass	Parenchyma	Trauma
Pneumothorax (Simple)	Air Leak	Traumatic PTX	Definition: Air in pleural space from trauma. Comment: Caused by rib fracture puncture or alveolar rupture.	• Sign: Visceral pleural line • Supine: Deep sulcus sign	Pleural Space	Trauma
Pneumothorax (Tension)	Air Leak	Tension PTX	Definition: Progressive accumulation of air under pressure. Comment: Hemodynamic collapse due to impaired venous return.	• Shift: Mediastinum away • Diaphragm: Inverted • Ribs: Splayed	Pleural Space	Trauma	118467 Tension
Pneumomediastinum	Air Leak	Mediastinal Emphysema	Definition: Air in mediastinum from airway/esophageal injury or Macklin effect. Comment: Risks: tracheobronchial rupture or esophageal perforation.	• Sign: Continuous diaphragm sign • Air: Streaks around heart/aorta	Mediastinum	Trauma	Pneumomediastinum Game
Hemothorax	Pleural Injury	Pleural Hemorrhage	Definition: Blood in pleural space. Comment: >50% hematocrit of blood. Large volume suggests arterial injury (intercostal/internal mammary).	• Density: High-attenuation fluid (≈60–80 HU) • Sign: Layering hematocrit effect	Pleural Space	Trauma
Flail Chest	Chest Wall Injury	Flail Segment	Definition: Segmental fractures of ≥3 adjacent ribs in ≥2 places. Comment: Causes paradoxical chest wall motion (inward on inspiration).	• Bone: Multiple segmental rib fractures • Lung: Underlying contusion	Chest Wall / Ribs	Trauma
Tracheal/Bronchial Rupture	Airway Injury	Tracheobronchial Injury	Definition: Tear in main airway. Comment: “Fallen lung sign” (lung drops away from hilum); massive air leak.	• Air: Massive pneumomediastinum / PTX • Sign: Fallen lung sign	Trachea / Bronchi	Trauma
Diaphragmatic Rupture	Diaphragm Injury	Traumatic Hernia	Definition: Tear in diaphragm allowing abdominal viscera into chest. Comment: Left > Right (liver protection). “Collar sign” from constricted viscera.	• Sign: Collar sign / Dependent viscera sign • Content: Stomach/bowel in hemithorax	Diaphragm	Trauma

MMM – Metabolic / Endocrine & Biochemical Disorders Affecting the Lung

Disease / Diagnosis	Grouped Category	Alternative Names	Definition & Comment	Imaging Features	Structure	Category	Faces & Case	Case Game Image
Amyloidosis, Diffuse Alveolar	Amyloid Deposition	Diffuse Septal Amyloidosis	Definition: Amyloid deposition in alveolar septa and vessel walls. Comment: Associated with systemic AL amyloidosis; restrictive physiology.	• Smooth septal thickening • Diffuse reticulation / GGO • Pleural effusions common	Interstitium	Metabolic	Faces of Amyloid Cases of Amyloid	Case 70F (Amyloid)
Amyloidosis, Nodular	Amyloid Deposition	Amyloidoma	Definition: Focal amyloid masses in parenchyma. Comment: Very slow-growing; mimics neoplasm.	• Solitary or multiple nodules • Coarse or eggshell calcification	Parenchyma	Metabolic	Faces of Amyloid Cases of Amyloid
Amyloidosis, Tracheobronchial	Amyloid Deposition	Airway Amyloidosis	Definition: Amyloid infiltration of trachea/bronchi. Comment: Spares posterior membrane (key distinguishing feature).	• Nodular airway wall thickening • Airway calcifications • Variable narrowing	Trachea / Bronchi	Metabolic	Faces of Amyloid Cases of Amyloid
Metastatic Calcification	Calcium Deposition	Uremic Pulmonary Calcification	Definition: Calcium deposition in normal lung from hypercalcemia/hyperphosphatemia. Comment: Seen in CKD and hyperparathyroidism.	• Centrilobular GGO nodules • High-attenuation parenchyma • Upper-lobe predominance	Alveoli / Interstitium	Metabolic
Pulmonary Alveolar Microlithiasis	Calcium Deposition	Microlithiasis	Definition: Inherited disorder with intra-alveolar calcium microliths. Comment: “Sandstorm lung.”	• Fine sand-like calcifications • “Black pleura sign” • Calcified crazy paving	Alveoli	Metabolic
Pulmonary Alveolar Proteinosis (PAP)	Surfactant Disorder	PAP	Definition: Surfactant accumulation due to impaired clearance (anti-GM-CSF antibodies). Comment: Classic “Crazy Paving.”	• Crazy Paving • Geographic distribution • Normal lung volumes	Alveoli	Metabolic
Lipoid Pneumonia (Exogenous)	Lipid Aspiration	Mineral Oil Pneumonia	Definition: Aspiration of lipid substances. Comment: Seen in elderly using mineral oil.	• Low-attenuation consolidation (-30 to -100 HU) • Crazy Paving • Dependent distribution	Alveoli	Metabolic
Niemann-Pick Disease	Lysosomal Storage	Foam Cell Lung	Definition: Sphingomyelinase deficiency causing lipid-laden macrophages. Comment: Multisystem storage disorder.	• Diffuse GGO + reticulation • Septal thickening • Hepatosplenomegaly	Interstitium	Metabolic

CCC – Circulatory Disorders Affecting the Chest

Disease / Diagnosis	Grouped Category	Alternative Names	Definition & Comment	Imaging Features	Structure	Category	Faces & Case	Case Game Image
Embolism, Acute PE	Pulmonary Artery Obstruction	Pulmonary Thromboembolism	Definition: Acute thrombotic occlusion of pulmonary arteries. Comment: “Saddle PE” straddles the bifurcation; risk of acute RV strain.	• CT: Central filling defect (“Polo Mint”) • CXR: Hampton’s Hump / Westermark Sign • Heart: RV dilation (RV/LV > 1)	Pulmonary Arteries	Circulatory
Embolism, Chronic	Pulmonary Artery Obstruction	CTEPH	Definition: Organized chronic thrombus causing luminal narrowing. Comment: Leads to Chronic Thromboembolic Pulmonary Hypertension (CTEPH).	• Vessel: Webs, bands, eccentric defects • Pattern: Mosaic perfusion • Heart: RV hypertrophy	Pulmonary Arteries	Circulatory
Embolism, Fat	Non-Thrombotic Embolism	Fat Embolism Syndrome	Definition: Fat droplets entering circulation after long-bone trauma. Comment: Triad: respiratory distress, petechial rash, confusion (24–72h).	• Pattern: Diffuse GGO and centrilobular nodules • Timing: 1–3 days post-injury	Capillaries	Circulatory
Embolism, Septic	Non-Thrombotic Embolism	Septic Emboli	Definition: Embolization of infected thrombi (endocarditis/IVDU). Comment: Frequently produces multiple small lung abscesses.	• Nodule: Multiple peripheral nodules • Cavity: Rapid cavitation • Sign: Feeding vessel sign	Peripheral Lung	Circulatory		Septic Emboli Game
Pulmonary Hypertension (Primary)	Pulmonary Vascular Disease	IPAH	Definition: Elevated PA pressure > 20 mmHg due to arteriolar remodeling. Comment: “Pruning” of peripheral vessels.	• Size: MPA > 29 mm • Heart: RV hypertrophy and dilation • Lung: Clear parenchyma	Pulmonary Artery	Circulatory
Pulmonary Venous Hypertension	Venous Disease	Post-Capillary PH	Definition: Elevated pulmonary venous pressure from left heart disease. Comment: Most common cause of pulmonary hypertension.	• Sign: Cephalization (upper-lobe diversion) • Septa: Kerley B lines • Pleura: Effusions	Pulmonary Veins	Circulatory
AVM (Arteriovenous Malformation)	Vascular Anomaly	PAVM	Definition: Direct communication between PA and PV without capillary bed. Comment: Associated with HHT; risk of paradoxical emboli (stroke/abscess).	• Nodule: Well-defined nodule • Vessels: Feeding artery and draining vein visible	Vessels	Circulatory	Faces of AVMs Cases of AVM’s	AVM Game
Vasculitis (ANCA)	Small Vessel Vasculitis	GPA / MPA	Definition: Autoimmune small vessel vasculitis of pulmonary capillaries. Comment: Important cause of diffuse alveolar hemorrhage.	• Pattern: Diffuse or patchy GGO (hemorrhage) • Nodule: Cavitating nodules (GPA/Wegener’s)	Capillaries	Circulatory
Pulmonary Edema (Cardiogenic)	Hydrostatic Edema	CHF	Definition: Fluid transudation into interstitium/alveoli from elevated LAP. Comment: Classic “Batwing” perihilar edema.	• Pattern: Perihilar GGO / consolidation • Septa: Smooth septal thickening • Heart: Cardiomegaly	Interstitium / Alveoli	Circulatory

III – Infiltrative Storage / Metabolic Diseases of the Lung

Disease / Diagnosis	Grouped Category	Alternative Names	Definition	Imaging Features	Structure	Category	Case Game Image
Amyloidosis, Diffuse Septal	Amyloidosis	Diffuse Alveolar Amyloidosis	Widespread amyloid deposition in alveolar septa. Associated with systemic AL amyloidosis.	• Pattern: Smooth interlobular septal thickening • Nodes: Calcified lymph nodes • Pleura: Effusions	Interstitium / Septa	Metabolic	Case 70F (Amyloid CT)
Amyloidosis, Nodular	Amyloidosis	Amyloidoma	Localized amyloid deposition forming a mass. Often incidental.	• Nodule: Solitary or multiple • Calcification: Central or diffuse	Parenchyma	Metabolic
Erdheim-Chester Disease	Histiocytosis	ECD	Non-Langerhans cell histiocytosis with multisystem involvement (Bone, Kidneys, Heart).	• Septa: Smooth or nodular septal thickening • Pleura: Pleural thickening • Bone: Bilateral osteosclerosis (long bones)	Interstitium	Metabolic
Gaucher Disease	Lysosomal Storage	Gaucher Lung	Glucocerebroside accumulation causing ILD and sometimes pulmonary hypertension.	• Pattern: Reticulonodular • Bone: Erlenmeyer flask deformity • Organ: Hepatosplenomegaly	Interstitium	Metabolic
Hermansky-Pudlak Syndrome	Lysosomal Storage	HPS Fibrosis	Albinism + bleeding diathesis + pulmonary fibrosis. Seen especially in Puerto Rico.	• Pattern: UIP-like with honeycombing • Distribution: Basal predominant	Interstitium	Metabolic
Lipoid Pneumonia (Exogenous)	Lipoid Accumulation	Mineral Oil Pneumonia	Aspiration of oily substances (mineral oil, lip balm). Chronic process.	• Density: Low attenuation (-30 to -100 HU) • Pattern: Crazy Paving • Location: Dependent	Alveoli	Metabolic
Niemann-Pick Disease	Lysosomal Storage	NPD Lung	Sphingomyelin storage disease with “foam cell” infiltration of lung.	• Pattern: Diffuse GGO / Reticulation • Septa: Septal thickening • Organ: Hepatosplenomegaly	Interstitium	Metabolic
Pulmonary Alveolar Microlithiasis	Calcific Deposition	PAM	Inherited disorder with widespread intra-alveolar calcium-phosphate microliths.	• Pattern: Sand-like calcifications • Sign: Black pleura sign • Sign: Calcified crazy paving	Alveoli	Metabolic
Pulmonary Alveolar Proteinosis (PAP)	Surfactant Disorder	PAP	Accumulation of surfactant in alveoli due to impaired macrophage clearance (anti-GM-CSF).	• Pattern: Crazy Paving • Distribution: Geographic / Map-like	Alveoli	Metabolic	Case 159L (PAP CT)
Pulmonary Hemosiderosis	Iron Storage	IPH	Recurrent diffuse alveolar hemorrhage leading to iron deposition in lung tissue.	• Acute: Diffuse GGO • Chronic: Fibrosis / Reticulation • MRI: Low signal (iron)	Alveoli / Interstitium	Metabolic

III Inherited Disorders Affecting the Lung

Disease / Diagnosis	Grouped Category	Alternative Names	Definition & Comment	Imaging Features	Structure	Category	Faces & Case	Case Game Image
Alpha-1 Antitrypsin Deficiency	Enzyme Deficiency	A1AT	Definition: Deficiency of protease inhibitor causing unopposed elastase injury. Comment: Causes early-onset panacinar emphysema.	• Pattern: Panacinar emphysema • Distribution: Basal predominance	Secondary Lobule	Inherited	Cases of
Birt Hogg Dube	Cystic Lung Disease	BHD Syndrome	Definition: AD disorder (FLCN mutation) with cysts, renal tumors, fibrofolliculomas. Comment: High pneumothorax risk.	• Cyst: Multiple thin-walled cysts • Location: Basal/Medial • Shape: Lentiform/irregular	Parenchyma	Inherited	Cases of Birt Hogg Dube
Cystic Fibrosis	CFTR Channelopathy	Mucoviscidosis	Definition: AR disease causing thick secretions & chronic infection. Comment: Most common lethal genetic disease in Caucasians.	• Airway: Upper-lobe bronchiectasis • Sign: Finger-in-glove mucus • Pattern: Tree-in-bud / Air trapping	Bronchi	Inherited
Hermansky-Pudlak	Lysosomal Storage	HPS Fibrosis	Definition: Albinism + bleeding + pulmonary fibrosis. Comment: Common in Puerto Rico.	• Pattern: UIP-like honeycombing • Distribution: Peripheral / Basal	Interstitium	Inherited	HPS Fibrosis
Primary Ciliary Dyskinesia	Ciliopathy	Kartagener Syndrome	Definition: Defective ciliary structure/function causing impaired clearance. Comment: Kartagener triad = Situs inversus + Bronchiectasis + Sinusitis.	• Airway: Diffuse bronchiectasis • Position: Situs inversus • Sign: Tree-in-bud	Bronchi	Inherited
Pulmonary Alveolar Microlithiasis	Calcific Deposition	PAM	Definition: SLC34A2 mutation causing intra-alveolar microliths. Comment: “Sandstorm lung.”	• Pattern: Diffuse calcified micronodules • Sign: Black Pleura Sign	Alveoli	Inherited
Sickle Cell (Acute Chest)	Hemoglobinopathy	ACS	Definition: Vaso-occlusive crisis in pulmonary vasculature. Comment: Leading cause of death in SCD.	• Pattern: New consolidation • Bone: H-shaped vertebrae • Pleura: Effusion	Vessels / Alveoli	Inherited
Tuberous Sclerosis Complex	Phakomatosis	TSC	Definition: AD disorder with widespread hamartomas. Comment: Lung: LAM cysts + MMPH micronodules.	• Lung: Cysts + micronodules • Kidney: AMLs • Brain: Cortical tubers	Systemic	Inherited
Lymphangioleiomyomatosis (LAM)	Cystic Lung Disease	LAM	Definition: Proliferation of LAM cells leading to cystic lung destruction. Comment: Sporadic or TSC-associated.	• Cysts: Diffuse, uniform, round • Volume: Hyperinflated lungs • Complications: PTX, Chylothorax	Parenchyma	Inherited		Case 92L (PTX in LAM)

CCC Congenital Disorders of the Lung

Disease / Diagnosis	Grouped Category	Alternative Names	Definition & Comment	Imaging Features	Structure	Category	Case Game Image
Agenesis / Hypoplasia	Developmental Failure	Lung Aplasia	Definition: Complete absence (Agenesis) or incomplete development (Hypoplasia) of lung tissue/vessels. Comment: “White-out” hemithorax with volume loss.	• Shift: Extreme mediastinal shift toward affected side • Opacity: Complete opacification • Ribs: Crowding	Lung / Bronchus	Congenital
Bronchogenic Cyst	Foregut Duplication	Mediastinal Cyst	Definition: Benign cyst formed from abnormal budding of ventral foregut. Comment: Lined by respiratory epithelium. Usually incidental unless infected.	• Position: Middle mediastinum (Subcarinal) • Density: Water (0–20 HU) or higher (protein) • Enhancement: None	Mediastinum	Congenital
CPAM / CCAM	Hamartomatous Lesion	Congenital Pulmonary Airway Malformation	Definition: Multicystic mass of pulmonary tissue with bronchial proliferation. Comment: Communicates with tracheobronchial tree (unlike sequestration).	• Type I: Large cysts (>2cm) • Type II: Sponge-like small cysts • Content: Air-fluid levels common	Parenchyma	Congenital
Diaphragmatic Hernia	Migration Defect	CDH	Definition: Defect in diaphragm allowing abdominal viscera into chest. Comment: Bochdalek (Posterior/Left) is most common. Causes pulmonary hypoplasia.	• Content: Bowel/Stomach in chest • Position: Posterior (Bochdalek) vs Anterior (Morgagni) • Lung: Compressed/Hypoplastic	Diaphragm	Congenital
Lobar Overinflation	Airway Obstruction	Congenital Lobar Emphysema (CLE)	Definition: Progressive overdistension of a lobe due to “ball-valve” obstruction. Comment: Not true emphysema (no destruction). LUL is most common site.	• Lucency: Hyperlucent, expanded lobe • Mass Effect: Mediastinal shift away • Vessels: Attenuated/Spaced out	Lobe (LUL)	Congenital
Scimitar Syndrome	Venous Anomaly	Hypogenetic Lung Syndrome	Definition: Partial anomalous pulmonary venous return from Right Lung to IVC. Comment: Associated with Right Lung Hypoplasia.	• Shape: Curved “Scimitar” vein along right heart border • Size: Small right lung • Heart: Dextroposition	Pulmonary Vein	Congenital	Case 153L
Sequestration	Vascular Anomaly	Bronchopulmonary Sequestration	Definition: Non-functioning lung tissue lacking bronchial connection. Connections: Arterial: Systemic supply from Aorta (Key finding).	• Vessel: Feeder artery from Aorta • Type: Intralobar (drain to PV) vs Extralobar (drain to Systemic) • Location: LLL (Posterior)	Lung / Vascular	Congenital
Tracheal Bronchus	Airway Anomaly	Pig Bronchus	Definition: Aberrant bronchus arising directly from trachea above carina. Comment: Usually on Right. Risk of intubation of only that segment.	• Anatomy: Bronchus from right tracheal wall • Risk: Atelectasis if blocked by ET tube	Trachea	Congenital

III Iatrogenic Disorders of the Lung

Disease / Diagnosis	Grouped Category	Alternative Names	Definition & Comment	Imaging Features	Structure	Category	Faces & Case	Case Game Image
Amiodarone Toxicity	Drug Toxicity	Amiodarone Lung	Definition: Lung injury from phospholipid accumulation due to chronic amiodarone use. Comment: High-attenuation lung and liver are distinctive.	• Density: Hyperdense consolidation • Pattern: Asymmetric septal thickening • Clue: Hyperdense liver	Interstitium	Iatrogenic	Faces of Amiodarone Toxicity Cases of Amiodarone Toxicity	Case 178L
Bleomycin Toxicity	Drug Toxicity	Chemo Lung	Definition: Chemotherapy-induced lung injury with endothelial damage. Comment: Worse with high FiO2.	• Early: Subpleural GGO • Late: Fibrosis (NSIP/UIP) • Distribution: Basal	Interstitium	Iatrogenic
Checkpoint Inhibitor Pneumonitis	Immunotherapy Complication	ICI Pneumonitis	Definition: Immune-mediated pneumonitis from PD-1/PD-L1/CTLA-4 inhibitors. Comment: Diagnosis of exclusion in oncology patients.	• Pattern: Organizing Pneumonia (OP) • Features: Peribronchial GGO • Clue: Non-infectious distribution	Interstitium	Iatrogenic
Radiation Fibrosis	Radiation Injury (Chronic)	Post-Radiation Scarring	Definition: Chronic lung scarring 6–12+ months after RT. Comment: Sharp geometric margins conform to radiation port.	• Shape: Straight-edged geometric opacity • Margins: Sharp • Volume: Loss with traction bronchiectasis	Interstitium	Iatrogenic
Radiation Pneumonitis	Radiation Injury (Acute)	Acute Radiation Injury	Definition: Acute inflammatory response 4–12 weeks after RT. Comment: Often steroid responsive.	• Texture: Hazy GGO • Location: Confined to radiation field • Sign: Does not respect fissures	Alveoli	Iatrogenic
Mendelson’s Syndrome	Anesthesia Complication	Chemical Pneumonitis	Definition: Aspiration of acidic gastric contents during anesthesia. Comment: Rapid-onset chemical burn reaction.	• Distribution: Gravity-dependent • Pattern: Consolidation / edema • Timing: Within hours	Alveoli	Iatrogenic
TRALI	Transfusion Reaction	Transfusion-Related Acute Lung Injury	Definition: Non-cardiogenic edema after transfusion. Comment: Leading cause of transfusion-related death.	• Pattern: Bilateral infiltrates • Heart: Normal size • Timing: Within 6 hours of transfusion	Capillaries	Iatrogenic
Ventilator-Induced Injury	Mechanical Ventilation	Barotrauma / VILI	Definition: Injury from high airway pressures or volumes. Comment: Occurs commonly in ARDS.	• Air: Pneumothorax / Pneumomediastinum • Tissue: Subcutaneous emphysema • Cysts: Pneumatoceles	Pleura / Interstitium	Iatrogenic

III Idiopathic Disorders of the Lung

Disease / Diagnosis	Grouped Category	Alternative Names	Definition	Imaging Features	Structure	Category
Acute Interstitial Pneumonia (AIP)	Acute / DAD Pattern	Hamman–Rich Syndrome	Rare, fulminant idiopathic lung injury characterized by Diffuse Alveolar Damage (DAD), leading to rapid respiratory failure.	• Pattern: Diffuse GGO • Late: Traction bronchiectasis • Sign: Crazy paving	Alveoli / Interstitium	Idiopathic
Cryptogenic Organizing Pneumonia (COP)	Organizing Pneumonia	BOOP (Historic)	Idiopathic inflammation with intraluminal granulation tissue (Masson bodies). Steroid responsive.	• Pattern: Patchy migratory opacities • Distribution: Peribronchial / Subpleural • Sign: Reverse Halo (Atoll)	Small Airways / Alveoli	Idiopathic
Desquamative Interstitial Pneumonia (DIP)	Smoking-Related	DIP	Smoking-related accumulation of pigmented macrophages in alveoli.	• Pattern: Diffuse GGO • Distribution: Lower lobes • Cysts: Tiny cysts within GGO	Alveoli	Idiopathic
Idiopathic Pulmonary Fibrosis (IPF)	Fibrosing (Chronic)	Cryptogenic Fibrosing Alveolitis	Chronic progressive fibrosing interstitial pneumonia; the most common idiopathic interstitial pneumonia.	• Pattern: UIP • Sign: Honeycombing • Distribution: Basal / Subpleural • Volume: Loss	Interstitium	Idiopathic
Lymphoid Interstitial Pneumonia (LIP)	Lymphoproliferative	LIP	Benign polyclonal lymphoid infiltration; associated with Sjögren’s and HIV, sometimes idiopathic.	• Cysts: Thin-walled perivascular cysts • Pattern: Diffuse GGO • Nodules: Centrilobular/Subpleural	Interstitium	Idiopathic
Nonspecific Interstitial Pneumonia (NSIP)	Fibrosing (Chronic)	NSIP	Inflammatory/fibrosing IIP with more uniform involvement and better prognosis than IPF.	• Pattern: GGO + Reticulation • Sign: Subpleural sparing • Note: Honeycombing uncommon	Interstitium	Idiopathic
Pleuroparenchymal Fibroelastosis (PPFE)	Fibrosing (Rare)	PPFE	Rare fibrosing disorder affecting pleura and subpleural lung, especially upper lobes.	• Distribution: Apical / Upper lobe • Sign: Platythorax • Pleura: Dense thickening	Pleura / Apices	Idiopathic
Respiratory Bronchiolitis–ILD (RB-ILD)	Smoking-Related	RB-ILD	Mildest smoking-related ILD; inflammation of respiratory bronchioles.	• Nodules: Centrilobular GGO nodules • Airway: Bronchial wall thickening • Distribution: Upper lobes	Bronchioles	Idiopathic

ER – Trauma Disorders of the Chest

Disease / Diagnosis	Grouped Category	Alternative Names	Definition & Comment	Imaging Features	Structure	Category
Air Embolism (Traumatic)	Embolism	Air Embolus	Definition: Air entering venous or arterial system after trauma. Comment: Can cause stroke if systemic.	• Vessel: Air in PA or Right Heart • Systemic: Air in Left Heart (critical)	Pulmonary Artery / Heart	Trauma
Aortic Pseudoaneurysm (Traumatic)	Vascular Injury	Chronic Traumatic Aneurysm	Definition: Contained rupture of aortic wall. Comment: Subacute/chronic; may present late.	• Shape: Saccular outpouching • Neck: Narrow • Finding: Mural thrombus	Aorta	Trauma
Aortic Transection / Injury	Vascular Injury	Traumatic Aortic Rupture	Definition: Full-thickness or partial tear from rapid deceleration. Comment: Classically at isthmus.	• Direct: Intimal flap / Pseudoaneurysm • Indirect: Mediastinal hematoma / Apical cap	Aorta (Isthmus)	Trauma
Cardiac Contusion	Cardiac Injury	Myocardial Contusion	Definition: Myocardial bruising from blunt trauma. Comment: RV most commonly injured.	• MRI: Focal edema (T2 high) / LGE • Echo: Wall motion abnormality	Myocardium	Trauma
Diaphragmatic Rupture	Diaphragm Injury	Traumatic Hernia	Definition: Tear allows abdominal organs into chest. Comment: Left > Right.	• Content: Stomach/bowel in chest • Sign: Collar sign	Diaphragm	Trauma
Embolism, Fat	Embolism	Fat Embolism Syndrome	Definition: Fat droplets enter circulation after long bone trauma. Comment: 24–72h delay; petechial rash.	• Pattern: Diffuse GGO • Nodules: Centrilobular nodules	Capillaries	Trauma
Flail Chest	Chest Wall Injury	Flail Segment	Definition: ≥3 adjacent ribs fractured in ≥2 places. Comment: Paradoxical motion.	• Bone: Multiple segmental fractures • Lung: Underlying contusion	Ribs	Trauma
Lung Contusion	Parenchymal Injury	Pulmonary Contusion	Definition: Alveolar hemorrhage/edema without laceration. Comment: Resolves in days.	• Pattern: Patchy GGO / Consolidation • Location: Adjacent to trauma	Alveoli	Trauma
Lung Laceration	Parenchymal Injury	Traumatic Pneumatocele	Definition: Parenchymal tear forming cavity. Comment: Often with surrounding contusion.	• Shape: Round cavity • Content: Air-fluid level	Parenchyma	Trauma
Pericardial Tamponade (Traumatic)	Cardiac Injury	Hemopericardium	Definition: Blood compresses heart causing obstructive shock.	• Fluid: High attenuation blood • Heart: RA/RV diastolic collapse	Pericardium	Trauma
Pneumomediastinum	Air Leak	Mediastinal Emphysema	Definition: Air in mediastinum (Macklin effect or airway injury).	• Sign: Streaky gas around heart • Extension: Neck/subcutaneous	Mediastinum	Trauma
Pneumothorax (Traumatic)	Air Leak	Simple PTX	Definition: Traumatic pleural air, often from rib fracture.	• Sign: Visceral pleural line • Supine: Deep Sulcus Sign	Pleural Space	Trauma

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III Inflammation – Immune

III Inflammation – Immune

Bronchiolitis Family Combination – Findings Inflamatory and Infectious Bronchiolitis

III Inflammation – Infection – Interface

Pneumonia Family

III Infection – Bacterial

Dedicated Mycobacterial

Atypical Infections

Viral Infections

Aspergillus Family

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Aspergillus Family

Aspergillus Family

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Cancer Family

Malignant Neoplasm – Infiltrative Type

BBB Benign Neoplasms

MMM Mechanical Disorders of the Lung

Aspiration Family

Aspiration Family

TTT Trauma

MMM – Metabolic / Endocrine & Biochemical Disorders Affecting the Lung

CCC – Circulatory Disorders Affecting the Chest

III – Infiltrative Storage / Metabolic Diseases of the Lung

III Inherited Disorders Affecting the Lung

CCC Congenital Disorders of the Lung

III Iatrogenic Disorders of the Lung

III Idiopathic Disorders of the Lung

ER – Trauma Disorders of the Chest

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