Lungs

 HIV  Fournier Gangrene
8 days after admission

2. Findings and Diagnosis

• Differential Diagnosis Table (TCV Disease Categories)

  TCV Category	Possible Diagnoses
  Infection	Severe pneumonia (e.g., bacterial, COVID-19, influenza)
  Inflammatory/Immune	Acute interstitial pneumonia (AIP), connective tissue disease-related lung injury
  Mechanical	Aspiration pneumonia (especially if gravity-dependent)
  Trauma	Pulmonary contusion post blunt chest trauma
  Metabolic	Uremic pneumonitis, pancreatitis-induced lung injury
  Iatrogenic	Drug-induced pneumonitis, post-transfusion acute lung injury (TRALI)
  Circulatory	Cardiogenic pulmonary edema (if overlapping with interstitial changes)
  Idiopathic	ARDS (when no clear etiology is identified, e.g., idiopathic AIP)

  Key Points & Pearls – Page 2

  • ARDS presents radiographically as bilateral, often patchy, airspace disease with GGO, consolidation, or both.

  • Differential is broad: includes infection, aspiration, inflammatory lung diseases, trauma, and cardiogenic edema.

  • Distribution helps refine diagnosis: dependent GGO/consolidation supports ARDS.

  • Pulmonary edema from heart failure may mimic ARDS, but cardiomegaly or pleural effusions help distinguish.

  • Ground-glass opacity without architectural distortion is typical in early ARDS — CT is more sensitive than CXR.

3. Clinical

PAGE 4 – INFO: Broader Clinical and Radiologic Context

Table 1 – Broad Disease Context

Category	Details
Definition	ARDS (Acute Respiratory Distress Syndrome) is a rapidly developing non-cardiogenic pulmonary edema due to diffuse alveolar damage.
Etiology	Sepsis (most common), aspiration, trauma, transfusion, pancreatitis, pneumonia, drug overdose, inhalation injury
Resulting Pathology	Inflammatory injury to the alveolar-capillary membrane causing increased permeability and flooding of alveoli with proteinaceous fluid
Structural Changes	Bilateral, diffuse alveolar infiltrates; hyaline membrane formation; alveolar collapse; interstitial edema
Functional Changes	Impaired gas exchange, hypoxemia refractory to oxygen, decreased lung compliance, increased work of breathing
Clinical Diagnosis	Based on Berlin criteria: acute onset, bilateral infiltrates, PaO₂/FiO₂ ratio < 300, absence of cardiogenic cause
Imaging Diagnosis	Chest X-ray: bilateral opacities without cardiomegaly. CT: dependent consolidation, ground-glass opacity, air bronchograms. On supine films, expect increased density in posterior and lower lung zones due to gravity-dependent settling of mucinous exudate.
Laboratory Workup	ABG (low PaO₂), elevated inflammatory markers (CRP, IL-6), normal BNP, normal cardiac enzymes, rule out infections
Treatment Strategies	Supportive care (low tidal volume ventilation, prone positioning), treat underlying cause, ECMO in severe cases, fluid management

Table 2 – Radiology Subtypes and Complications

Subtype/Complication	Relevance to ARDS
Lobar Pneumonia	Can mimic early ARDS radiographically; usually focal and unilateral
Bronchopneumonia	May precede or coexist with ARDS; patchy consolidation more likely to involve airways
Atypical Pneumonia	Overlaps with ARDS patterns; ground-glass predominance but usually less severe and more localized
Aspiration Pneumonia	Important cause of ARDS, especially in ICU; may show lower lobe or posterior consolidations
Pulmonary Abscess	Rare complication of infection in ARDS patients; look for cavitation within consolidations
Empyema	Secondary to pneumonia; look for loculated pleural collections—usually not a primary feature of ARDS
Necrotizing Pneumonia	Severe bacterial pneumonia may lead to necrosis and ARDS; differentiated by cavitation and clinical deterioration
Fibrosis (Chronic ARDS)	Late-stage complication; CT shows architectural distortion, traction bronchiectasis, and volume loss

Key Points and Pearls Table

Insight	Explanation
Bilateral Symmetric Opacities	Hallmark of ARDS; helps distinguish from lobar or segmental pneumonia
Heart Size Matters	A normal-sized heart argues against cardiogenic pulmonary edema
CT for Clarification	Helpful in equivocal cases or when pneumonia, hemorrhage, or embolism are in the differential
Early Diagnosis Saves Lungs	Timely recognition and low tidal volume ventilation reduce progression to fibrosis
Follow-Up Imaging	Needed to track progression or response to treatment, particularly in ventilated patients
Pattern Evolution	Expect evolution from ground-glass → consolidation → possible fibrosis in chronic ARDS
Posterior-Dependent Opacities in Supine Position	Heavy mucinous exudate in ARDS settles posteriorly in supine patients, creating gravity-dependent opacities most visible in lower and posterior zones on portable AP chest X-rays.

 

4. Historical and Cultural

• PAGE 5 – OTHER: Historical and Cultural Dimensions

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  Table 1 – Cultural Reflections on Radiologic Units and Diagnosis

  Radiologic Term	Etymology / Cultural or Metaphoric Reflection
  Ground-Glass Opacity	Named for translucent, frosted glass—suggests partial visual obscuration. Reflects partial alveolar filling, and evokes fragility and ambiguity.
  Consolidation	Derived from Latin consolidare (to make firm/solid). Implies transformation of normally airy lung tissue into a dense, non-aerated state.
  Air Bronchogram	Radiologic sign resembling tree branches silhouetted in fog—symbolic of life amid chaos in a flooded lung.
  Silhouette Sign	“Silhouette” comes from art, indicating contour visibility. Loss of this sign on X-ray suggests adjacent density obscuring anatomic boundaries.

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  Table 2 – Medical History Related to Disease

  Topic	Historical Significance and Relevance to ARDS
  Berlin Definition (2012)	Provided modern diagnostic framework for ARDS with severity stratification based on PaO₂/FiO₂ ratio and imaging criteria.
  ARDS First Described (1967)	Ashbaugh et al. published the first case series identifying ARDS as a clinical-radiologic syndrome of hypoxia and diffuse lung injury.
  Ventilation Strategy Evolution	Introduction of low tidal volume ventilation by the ARDSNet trial (2000) became the gold standard, significantly reducing mortality.
  COVID-19 Pandemic (2020+)	Global surge of viral pneumonia-induced ARDS re-emphasized importance of imaging, ventilator management, and ICU triage.

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  Table 3 – Arts and Humanities (Alphabetical)

  Discipline	Reflection of ARDS and Respiratory Illness
  Dance	Depicts the body’s limits—choreography that focuses on breathlessness mirrors ARDS patients’ physical and emotional struggle.
  Literature	Works like The Plague by Camus and The Diving Bell and the Butterfly reflect confinement, as experienced in severe respiratory illness.
  Music	Pieces evoking breath or its absence (e.g., Adagio for Strings) have been used to memorialize ARDS victims in pandemic memorials.
  Painting	Expressionist art such as Edvard Munch’s The Scream symbolizes silent air hunger, mirroring dyspnea in ARDS.
  Sculpture	Compressed or fragmented forms can represent alveolar collapse and distortion in the fibrotic stages of ARDS.

5. MCQs

PAGE 6 – MULTIPLE CHOICE QUESTIONS (MCQs)

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Basic Science

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Clinical

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Radiology

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6. Memory Image

Memory Images
The Lungs get heavy with fluid

which sinks to the dependent portions of the lungs
and in the ICU setting with the
patient in supine position
will sink posteriorly

Anteroposterior Density Gradient

Memory Image Idea

Title: “The Drowning Lungs”

• Visual metaphor: Lungs as translucent sea creatures submerged in misty blue fluid, with branching bronchial trees resembling coral struggling to breathe.

• Style: Surrealist, soft pastel or digital watercolor