50 Nodular/Reticulonodular Opacities on High-Resolution Computed Tomography

CLINICAL IMAGAGINGAN ATLAS OF DIFFERENTIAL DAIGNOSIS

EISENBERG

DR. Muhammad Bin Zulfiqar PGR-FCPS III SIMS/SHL

• Fig C 50-1 Pulmonary lymphangitic carcinomatosis. Nodular thickening of the interlobular septa (curved arrows) and interlobar fissure (straight arrows).88

• Fig C 50-2 Hematogenous metastases. Sharply defined nodules. Although some nodules (arrow) appear to be related to small vascular branches, most nodules lack a specific relationship to lobular structures and appear to be random in distribution. Note the subpleural nodules and lack of septal thickening.88

• Fig C 50-3 Bronchioloaloveolar carcinoma. (A) Areas of consolidation in the right lower lobes, ill-defined nodules (some of which appear to be centrilobular), and multiple small, well-defined nodules. (B) Targeted view of the left lung shows numerous small nodules, at least some of which show a random distribution similar to hematogenous metastases. Note the presence of subpleural nodules.88

• Fig C 50-4 Kaposi's sarcoma. (A, B) Ill-defined nodules (arrows) in the parahilar and peribronchovascular regions.88

• Fig C 50-5 Sarcoidosis. “Perilymphatic” distribution of numerous small nodules in relation to the parahilar, bronchovascular interstitium. The bronchial walls appear irregularly thickened. Subpleural nodules (small arrows) are seen bordering the costal pleural surfaces and right major fissure. This appearance is virtually diagnostic of sarcoidosis. Clusters of subpleural granulomas (large arrows) have been termed pseudoplaques.88

• Fig C 50-6 Silicosis. (A) Conventional CT scan shows numerous lung nodules bilaterally, with relative sparing of the lung periphery. (B) HRCT at the same level more clearly defines the presence of subpleural nodules (small arrows). The nodules are smoothly marginated and sharply defined. The profusion of nodules is more easily evaluated on the conventional CT.88

• Fig C 50-7 Tuberculosis (endobronchial spread in reactivation disease). Typical appearance of numerous, diffuse, poorly defined nodules, some of which are perivascular and centrilobular.88

• Fig C 50-8 Tuberculosis (miliary). Numerous well-defined 1-2-mm nodules diffusely distributed through the right lower lobe. Some nodules appear septal (arrows) or subpleural, whereas others appear to be associated with small feeding vessels, suggesting a hematogenous origin.88

• Fig C 50-9 Mycobacterium avium-intracellulare complex (MAC) infection. Characteristic findings of bronchiectasis and small nodules and clusters of nodules in the peripheral lung.54

• Fig C 50-10 Invasive pulmonary aspergillosis. Multiple pulmonary nodules are associated with the halo sign.88

• Fig C 50-11 Septic pulmonary emboli. (A, B) Scattered, mostly peripheral, poorly defined foci of air-space consolidation, many of which contain varying degrees of cavitation. Note that a number of these appear to be associated with “feeding” vessels (arrows), suggesting a hematogenous origin.88