Paul S. Wheeler

Radiologic-pathologic correlation of the CT halo sign in invasive pulmonary aspergillosis

Invasive pulmonary aspergillosis in the immunocompromised host is difficult to diagnose. Early therapy with amphotericin B improves survival. We correlated early pathologic findings with high-resolution CT of a fixed-inflated air-dried lung obtained from an autopsied patient with invasive pulmonary aspergillosis. Two distinct types of lesions were found radiologically. A large zone of air space consolidation was shown to be a confluent bronchopneumonia, and small halo-like lesions were shown to correspond to a central fungal nodule surrounded by a rim of coagulative necrosis. The halo lesion may represent an early specific sign by which invasive pulmonary aspergillosis can be diagnosed.

Computed tomography of inflation-fixed lungs: the beaded septum sign of pulmonary metastases.

Radiographic identification of pulmonary metastases has proved to be a challenging problem. We applied high resolution CT (HRCT) to 180 postmortem lung specimens prepared by a method that allows for direct one-to-one pathologic-radiologic correlation. Of the 180 lungs, 32 had pulmonary metastases. The location, number, size, and interstitial changes were evaluated in 32 cases with pulmonary metastases. The pulmonary metastases were peripheral lesions in 94% of these 32 patients, and multiple tumors were found in 91% of these cases. The metastases were <1 cm in diameter in 78%. Twenty-two of the 32 cases (69%) had obvious interstitial changes. In 19 of these 22 cases the interstitial change was characterized by the appearance of a “beaded septum” on HRCT. This beaded septal change corresponded directly to tumor growth in pulmonary capillaries and lymphatics and the septal interstitium. This sign was not noted in any of the specimens with pulmonary edema or fibrosis or in normal lungs. We believe that detection of the beaded septum sign on HRCT is highly suggestive of pulmonary metastases.

CT of inflation-fixed lungs: Wedge-shaped density and vascular sign in the diagnosis of infarction

To evaluate the role of high resolution CT (HRCT) in the diagnosis of pulmonary infarcts, we selected 83 postmortem lung specimens with subpleural densities from a collection of 180 lungs that had been prepared by a method which allows for a direct radiologic-pathologic correlation. Twelve of the lungs had pulmonary infarcts and 71 lungs had other disorders that had produced a subpleural shadow on HRCT. Lungs were evaluated for the presence of wedge-shaped pleural-based densities and for the presence of an associated vascular sign. There was no significant difference in the incidence of wedge-shaped densities on HRCT between lungs with pulmonary infarcts and lungs with pulmonary hemorrhage, pneumonia, tumor, or edema (p greater than 0.05). A vascular sign associated with a subpleural density was, however, more common (p less than 0.01) in lungs with pulmonary infarcts. We suggest that the vascular sign associated with a wedge-shaped density may be of importance in diagnosing pulmonary infarcts by HRCT.

Jugular venous thrombosis: Diagnosis by computed tomography

Thrombosis of the internal jugular vein (TIJV) was diagnosed by CT in five patients. Clinical presentations included unexplained fever (four patients), swollen neck (three patients), and mediastinal widening (one patient). Factors contributing to TIJV included placement of a central venous catheter (three patients) and neck surgery (two patients). In two patients left TIJV occurred after right sided venous catheterization. The CT findings consisted of enlargement of the thrombosed vein, a nonenhancing filling defect in the lumen of the affected vessel, an enhancing vessel wall, and opacification of collateral venous channels.

CT-pathology correlation of amiodarone lung

Eleven isolated lungs from patients who had received amiodarone therapy and 22 other lungs from age-race-sex-matched controls autopsied at The Johns Hopkins Hospital were inflation fixed, air dried, and examined by high resolution CT (HRCT). The HRCT findings were directly correlated with gross and histologic changes in these lungs. Intralobular septal thickening and visceral pleural thickening on postmortem HRCT were significantly more severe in the lungs from patients who had received amiodarone than in the controls (p < 0.05). These HRCT findings were directly associated with the presence of mural foam cells and intraalveolar foam cells. These results suggest that amiodarone therapy may lead to the accumulation of mural and intraalveolar foam cells, and the accumulation of these foam cells may account for the changes seen on HRCT.

Illustrative cases in pericardial effusion misdetection: correlation of echocardiography and CT.

Eight equivocal two-dimensional echocardiograms with concurrent CT scans were evaluated to identify potential pitfalls in pericardial effusion detection. By echocardiography, two pleural effusions were felt to be pericardial, two hemopericardiums were interpreted as normal myocardium, three loculated pericardial effusions were not seen or were misinterpreted as other mediastinal collections, and one epicardial lipoma was called a pericardial effusion. When the clinical suspicion for pericardial effusion does not correlate with echocardiographic findings, CT scanning may be the definitive arbiter of pericardial disease.

The lucent cleft, a new radiographic sign of cervical disc injury or disease

Moderately severe neck injury or disease may be associated with negative routine radiographs. Three cases are presented which show small, smooth, lucent clefts adjacent to the vertebral body end-plate anteriorly, seen only on the extension lateral view. This was the only radiographic sign of cervical injury or disease. An explanation of the finding is given and it is distinguished from the well known vacuum phenomena of disc degeneration.

Inflation-fixed lungs: pathologic-radiologic (CT) correlation of lung transplantation.

Pulmonary infections and lung rejection are the two major complications of lung transplantation. Although the therapies for these two processes differ greatly, they often cannot be differentiated using standard radiography. We applied high resolution CT (HRCT) to seven lung specimens that were obtained from patients who had received a heart-lung transplant. The lungs were fixed by a method that allows for direct one-to-one pathologic-radiologic correlation. We found: (a) that in contrast to the extensive changes present microscopically, acute lung allograft rejection was characterized by only minor changes on HRCT; (b) that bronchiolitis obliterans, the hallmark of chronic lung allograft rejection, was not reliably identifiable on HRCT; (c) that bronchiectasis with associated peribronchial inflammation and fibrosis, a common finding in lung allograft rejection, was identifiable on HRCT, but that the HRCT appearance of this lesion was not specific for rejection; and (d) that pulmonary infections were often identifiable as a mixed airway-interstitial process on HRCT.

Computed tomography of rounded atelectasis

High resolution CT of a fixed-inflated air-dried lung was obtained from a patient with rounded atelectasis. The dense periphery of the mass was shown to correspond to an invagination of the pleura, and the central lucency to slightly aerated atelectatic lung parenchyma.