RT 304 - Pathology: Respiratory System Prefinals

Cystic fibrosis

Genetic defect on chromosome 7; thick mucus blocks airways and glands. Imaging clue: Thick bronchial walls, mucus plugging, hyperinflated “dirty chest.”

Hyaline membrane disease / RDS

Premature infant respiratory distress due to lack of surfactant; affects alveoli. Imaging clue: Diffuse granular/ground-glass lungs with air bronchograms.

Bronchial atresia

Congenital absence of bronchial connection; mucus-filled segment. Imaging clue: Hyperlucent lung segment with central bronchocele.

Pulmonary sequestration

Isolated lung tissue without normal bronchial connection, usually lower lobes. Imaging clue: Homogeneous mass with separate systemic blood supply.

Congenital diaphragmatic hernia

Abdominal contents pass into thorax through diaphragm defect. Imaging clue: Bowel loops in thorax and mediastinal shift.

Croup (laryngotracheobronchitis)

Viral swelling of subglottic airway; parainfluenza listed. Imaging clue: Steeple/hourglass narrowing of airway.

Epiglottitis

Acute bacterial infection; H. influenzae type B listed. Imaging clue: Enlarged “thumb-shaped” epiglottis on lateral neck X-ray.

Lobar (alveolar) pneumonia

Infection fills alveoli with exudate, usually one lobe. Imaging clue: Homogeneous consolidation with air bronchogram.

Bronchopneumonia

Patchy infection spreads from bronchi to adjacent alveoli. Imaging clue: Scattered patchy infiltrates; slides note no air bronchogram.

Interstitial pneumonia

Inflammation of alveolar walls/interstitium; viral or Mycoplasma listed. Imaging clue: Reticular/linear pattern; honeycomb in chronic cases.

Aspiration pneumonia

Inhaled gastric/oral material; associated with anesthesia, coma, swallowing disorder. Imaging clue: Patchy densities in dependent lung segments, often right lower lobe.

Lung abscess

Localized pus-filled cavity; bacterial infection or aspiration. Imaging clue: Thick irregular-walled cavity with air-fluid level.

Primary pulmonary TB

Initial infection due to Mycobacterium tuberculosis. Imaging clue: Upper-lobe consolidation with enlarged lymph nodes (“Ghon complex”).

Secondary/reactivation TB

Dormant TB reactivates, often with low immunity. Imaging clue: Upper-lobe cavitation with thick irregular walls and fibrosis.

Miliary TB

Widespread blood-borne TB. Imaging clue: Numerous fine uniform nodules in both lungs (“millet seed”).

Histoplasmosis

Fungal infection from Histoplasma capsulatum; may resemble TB. Imaging clue: Nodules with target or popcorn calcification.

Coccidioidomycosis

Fungal infection due to Coccidioides immitis. Imaging clue: Small peripheral consolidations and hilar adenopathy.

Sarcoidosis

Multisystem granulomatous disorder; cause unknown in slides. Imaging clue: Bilateral hilar enlargement (“1-3 sign

Chronic bronchitis

Long-term mucus overproduction and bronchial inflammation; smoking/pollution listed. Imaging clue: Increased bronchial markings, “dirty chest,” hyperinflation.

Emphysema

Alveolar wall destruction causes air trapping. Imaging clue: Flattened diaphragm, enlarged retrosternal space, bullae.

Asthma

Reversible airway narrowing from hypersensitivity. Imaging clue: Hyperinflation, increased lung lucency, normal vascular markings.

Bronchiectasis

Permanent bronchial dilatation from chronic/recurrent infection. Imaging clue: Cystic or honeycomb pattern with air-fluid levels.

Silicosis

Fibrotic reaction to inhaled silica; mining/sandblasting listed. Imaging clue: Upper-lobe small nodules and calcified “eggshell” lymph nodes.

Asbestosis

Fibrosis due to asbestos fibers; pleura/lower lobes. Imaging clue: Pleural plaques and calcified diaphragm; “shaggy heart” term in slides.

Anthracosis

Coal dust accumulation in lungs (“black lung”). Imaging clue: Reticular markings and granular nodules.

Solitary pulmonary nodule (SPN)

Single round lung lesion; may be benign or malignant. Imaging clue: Smooth/calcified suggests benign in slides; spiculated/irregular suggests malignant.

Bronchial adenoma

Low-grade malignant tumor in bronchial glands. Imaging clue: Central mass with lobar collapse/atelectasis.

Bronchogenic carcinoma

Primary malignant lung tumor; smoking/carcinogen inhalation listed. Imaging clue: Hilar mass, irregular cavitation, absence of air bronchogram.

Pulmonary metastases

Cancer spreads to lungs from another organ via blood. Imaging clue: Multiple round nodules (“cannonball lesions”).

Pulmonary embolism (PE)

Clot blocks pulmonary artery; DVT listed as cause. Imaging clue: Wedge-shaped opacity (“Hampton’s hump”) or vessel cutoff on CT.

Septic embolism

Bacterial emboli cause lung infection; endocarditis/IV drug use listed. Imaging clue: Multiple ill-defined opacities and cavitations.

Pulmonary arteriovenous fistula

Abnormal artery-vein communication; congenital in slides. Imaging clue: Rounded soft-tissue mass with feeding artery and draining vein.

Atelectasis

Lung collapse due to obstruction or compression. Imaging clue: Increased density; mediastinum shifts toward the collapse.

Adult respiratory distress syndrome (ARDS)

Severe respiratory failure from diffuse alveolar damage. Imaging clue: Patchy bilateral opacities with normal heart size.

Intrabronchial foreign body

Inhaled object obstructs bronchus; right side common in slides. Imaging clue: Complete obstruction: atelectasis. Partial: hyperinflation with mediastinal shift.

Pneumomediastinum

Air leaks into mediastinum. Imaging clue: Air streaks outline heart/vessels (“spinnaker sign”).

Subcutaneous emphysema

Air trapped in chest-wall/neck soft tissues. Imaging clue: Air streaks outline muscle bundles; soft-tissue lucencies.

Pneumothorax

Air in pleural cavity causing lung collapse. Imaging clue: Absent vascular markings, visible pleural line, hyperlucency.

Pleural effusion

Fluid in pleural space; causes listed include CHF, infection, malignancy. Imaging clue: Blunted costophrenic angle and meniscus sign.

Empyema

Pus in pleural cavity, often from pneumonia/abscess. Imaging clue: Loculated opacity; possible air-fluid level.

Mediastinal masses

Tumor or cyst in anterior, middle, or posterior mediastinum. Imaging clue: Soft-tissue mass and displacement of structures; CT helps define cystic vs solid.

Diaphragmatic paralysis

Loss of movement due to phrenic nerve injury. Imaging clue: Elevated dome; paradoxical movement on sniff test.

Eventration of diaphragm

Congenital diaphragm weakness, often left-sided. Imaging clue: Smooth elevated contour with normal bowel below.

Secondary elevation of diaphragm

Apparent high diaphragm; causes listed include ascites, obesity, pregnancy, abscess. Imaging clue: Diffuse elevation of hemidiaphragm and reduced motion.