Lungs Fx 1 Consolidation Inferior Lingular 2 Air Bronchogram Dx Pneumonia CT (axial) 52M cough and fever

Lungs

2. Findings and Diagnosis

Lingular Pneumonia
52 year old male presents with a cough and fever
CT scan in the axial plane shows a lingular consolidation with air bronchograms and a positive silhouette sign. Both the superior and inferior lingular segments are involved
Ashley Davidoff MD TheCommonVein.net

Table 1 – Observations and Definitions

Observation	Definition
Fx 1 – Consolidation of Inferior Lingula	Homogeneous increase in pulmonary attenuation due to alveolar filling, typically with exudate or inflammatory cells.
Fx 2 – Air bronchogram	Air-filled bronchi that remain visible within consolidated lung tissue, indicating patent airways amidst alveolar filling.

Table 2 – Explanation of Radiological Findings

Finding	Definition	Mechanism	Clinical Value
Consolidation	Opacification of lung parenchyma due to alveolar exudate	Alveoli are filled with fluid, pus, or cells	Strongly suggests infectious process like pneumonia
Air bronchogram	Lucent airways seen within opacified lung	Bronchi remain aerated while alveoli are fluid-filled	Confirms alveolar rather than interstitial pattern
Lingular opacity	Density in left upper lobe’s lingular segment	Often affected in aspiration or dependent infections	Explains silhouette sign (loss of left heart border)
No cavitation	Absence of gas-filled necrotic area	Early or non-necrotizing infection	Rules out abscess or necrotizing pneumonia

Table 3 – Associated Findings

Associated Finding	Relevance to Diagnosis
Acute fever and cough	Classic symptoms of pneumonia
Segmental distribution	Favors bronchopneumonia or lobar pneumonia pattern
Absence of cavitation or mass effect	Supports diagnosis of uncomplicated infection
No mediastinal lymphadenopathy	Makes TB or malignancy less likely in this context

Table 4 – Classification of the Primary Finding (Consolidation)

Type of Consolidation
Lobar
Segmental
Patchy
Interstitial
Round (more common in children)
Organizing (seen in subacute or resolving stages)

Table 5a – Differential Diagnosis: Most Likely

Disease Category	Specific Diagnosis
Infectious – Bacterial	*Lobar pneumonia (Streptococcus pneumoniae)*
Infectious – Atypical	Mycoplasma pneumonia, Chlamydia pneumonia
Infectious – Aspiration	Anaerobic infection affecting dependent segments (e.g., lingula)

Table 5b – Differential Diagnosis: Other Possibilities

Disease Category	Specific Diagnosis
Infection – Viral	Influenza, SARS-CoV-2
Inflammatory	Cryptogenic organizing pneumonia (COP)
Neoplasm – Malignant	Bronchoalveolar carcinoma (non-resolving consolidation)
Infiltrative	Sarcoidosis with alveolar pattern
Iatrogenic	Drug-induced lung disease (e.g., amiodarone toxicity)
Idiopathic	NSIP, UIP if chronic features evolve
Trauma	Pulmonary contusion (if trauma history present)

Table 6 – Radiologic Diagnosis Strategy & References

Aspect	Details
Modality of Choice	CT chest (non-contrast often sufficient)
Imaging Role	Identifies lobar or segmental consolidation, assesses extent and complications
Best Sequences/Views	Axial lung windows; coronal reformats for segmental anatomy
Recommended Guidelines	ACR Appropriateness Criteria – Acute Respiratory Illness in Immunocompetent Patient (https://www.acr.org/Clinical-Resources/ACR-Appropriateness-Criteria)

Table 7 – Pearls (Imaging & Pattern Recognition)

Pearl
Air bronchograms are reliable markers of alveolar consolidation, not present in atelectasis with complete airway obstruction.
Lingular consolidation abuts the heart border—can mimic middle lobe disease on frontal CXR.
Lack of volume loss differentiates consolidation from atelectasis.
Chronic consolidation requires follow-up imaging to exclude neoplasm or organizing pneumonia.

3. Clinical

🔵 Page 3 – Diagnosis and Clinical Context (Updated)

Dx Focus:
In this patient, the diagnosis was pneumonia, with imaging showing consolidation in the lingula and clinical symptoms of fever and cough. While this case represents a classic community-acquired infectious pneumonia, the term “pneumonia” is used more broadly in pulmonary medicine, encompassing a wide range of infectious and non-infectious conditions.

Table 1 – Clinical Perspective

Element	Detail
Definition	Pneumonia is inflammation of the lung parenchyma, typically infectious, but may also be immune-mediated or idiopathic.
Caused by	Microbial agents (bacteria, viruses, fungi); or non-infectious causes like autoimmune, hypersensitivity, or idiopathic mechanisms.
Pathophysiology and Pathogenesis	Alveolar infection or inflammatory infiltration leads to exudation, fibrosis, and disrupted gas exchange.
Structural Changes	Consolidation, ground-glass opacities, reticulation, traction bronchiectasis depending on type.
Functional Impact	Impaired oxygenation; may progress to fibrosis in interstitial pneumonias.
Clinical Presentation	Acute (infectious) or chronic (interstitial); varies from fever and cough to dyspnea and fatigue.
Labs	Microbial cultures, autoimmune serologies, eosinophil counts, bronchoalveolar lavage in ILD.
Treatment	Infectious: antibiotics; Interstitial: corticosteroids, immunosuppressants, antifibrotics.
Prognosis	Acute forms treatable; chronic interstitial pneumonias often progressive, may require lung transplant.

Table 2 – Classification of Pneumonia (Expanded)

Type	Description
By Acquisition	Community-Acquired (CAP), Hospital-Acquired (HAP), Ventilator-Associated (VAP), Healthcare-Associated (HCAP)
By Pathogen	Bacterial (typical/atypical), Viral, Fungal, Parasitic
By Anatomic Pattern	Lobar, Segmental (bronchopneumonia), Interstitial, Round
By Host Immune Status	Immunocompetent vs Immunocompromised
By Mechanism	Aspiration, Hematogenous, Direct invasion
By Clinical Course	Acute, Chronic, Recurrent
By Pathology (Non-Infectious Interstitial Pneumonias)	– UIP: Patchy fibrosis, honeycombing, poor prognosis – NSIP: Uniform GGO and fibrosis, better prognosis – Eosinophilic Pneumonia: Infiltration with eosinophils, often steroid-responsive – COP (Organizing Pneumonia): Plugging of airways with granulation tissue, subacute course

Table 3 – Pearls (Clinical Focus, Expanded)

Clinical Insight
The term pneumonia is not limited to infection—used for a range of interstitial lung diseases (e.g., NSIP, UIP, eosinophilic pneumonia).
Classic pneumonia shows lobar consolidation and air bronchograms, while interstitial types show reticular patterns, GGO, and chronic progression.
Eosinophilic pneumonia may mimic infection but shows peripheral infiltrates and eosinophilia.
UIP and NSIP often show lower lobe and subpleural predominance—important to distinguish from atypical or unresolved pneumonia.
Always integrate clinical duration and systemic features—acute vs subacute vs chronic—when evaluating opacities labeled “pneumonia.”
Editorial: “Pneumonia” in radiology is often a pattern descriptor; confirmation requires clinical and sometimes histologic correlation.

4. Historical and Cultural

Page 4 – History, Culture, and Art

Category	Unit	Detail
Etymology	Pneumonia	From Greek pneumon (lung) + -ia (condition), meaning “inflammation of the lungs.”
History in Medicine	Early Recognition	Hippocrates described pneumonia as a disease with fever and cough in his treatises.
	Anatomical Insight	In the 19th century, Laënnec used the stethoscope to correlate auscultation findings with lung pathology like consolidation.
	Diagnostic Evolution	The discovery of X-rays in 1895 by Wilhelm Roentgen enabled visualization of pulmonary consolidation.
	Treatment Milestone	The advent of penicillin in the 1940s revolutionized pneumonia treatment, reducing mortality dramatically.
Culture and Art	Cultural Insights	Historically feared due to its rapid course and mortality; dubbed “the old man’s friend” because of its relatively painless death in the elderly.
	Metaphorical Imagery	Lungs clouded with infection resemble fogged windows—obscuring clarity, life, and breath.
	Sociomedical Beliefs	Pneumonia was once considered a result of “bad air” or miasma before germ theory.
	Artistic References	Thomas Mann’s The Magic Mountain captures the sanatorium culture for chronic pulmonary infections including pneumonia and tuberculosis.
	Literature	Shakespeare referred to lung illness obliquely in works like Othello, where Desdemona’s symptoms suggest respiratory disease.
	Notable Figures	Sir William Osler called pneumonia the “captain of the men of death,” recognizing its prevalence and lethality.
	Historical Patients	U.S. President William Henry Harrison died of pneumonia just 31 days after taking office in 1841.
	Quotes	“Pneumonia may well be called the friend of the aged” – Sir William Osler

5. MCQs

Page 5 – MCQs (7 Total)

Basic Science (2)

Q1. Which of the following best describes the pathophysiology of lobar pneumonia?
A. Immune complex deposition in alveolar septa
B. Alveolar filling with fibrin-rich exudate and neutrophils
C. Peribronchial lymphoid hyperplasia
D. Bronchiolar smooth muscle hypertrophy