Faculty Bibliography

CT was compared to fiberoptic bronchoscopy in a large series of patients to study the value of CT for visualizing bronchial disease. CT scans were available for review in 64 cases in which focal airway disease was identified with fiberoptic bronchoscopy and in 38 patients in whom the airways appeared normal at bronchoscopy. CT was positive in 59 of 64 cases in which lesions were detected endoscopically. If the results are analyzed according to the extent of involvement of individual bronchi, CT successfully identified 88 (90%) of 98 lesions. CT correctly excluded disease in 35 (92%) of 38 cases that were subsequently verified to be normal by fiberoptic bronchoscopy. In no case was the diagnosis of malignancy missed by CT. While extremely accurate in detecting focal lesions, CT was inaccurate in predicting whether a given abnormality was endobronchial, submucosal, or extrinsic (peribronchial). In three cases CT failed to detect submucosal extension into the left mainstream bronchus, which has important implications concerning the value of CT in staging bronchial malignancy. It is concluded that CT is helpful when bronchoscopy is contraindicated or refused. CT may also be used in selected cases when there is low clinical suspicion of endobronchial disease and as a complementary procedure to fiberoptic bronchoscopy for outlining the exact location of major mediastinal and hilar vessels, lymph nodes, and tumor in relation to adjacent airways

The CT findings of 38 consecutive patients with acute appendicitis are analyzed, described, and illustrated. CT showed intraabdominal disease in 92% of patients and made a specific diagnosis of appendicitis in 79% of cases. The most common CT findings were pericecal inflammation (68%), abscess (55%), calcified appendicolith (23%), and an abnormal appendix (18%). CT had a sensitivity similar to that of contrast enema examinations, but it correlated much better with the surgical findings in detecting the precise nature, extent, and location of the disease process. Normal CT does not exclude appendicitis, since mild forms without periappendiceal disease may escape detection

To evaluate the role of computed tomography (CT) in the investigation of pulmonary nodules, a special reference phantom that enabled CT densitometric measurements independent of variations between scanners and patients was used in ten institutions. A total of 384 nodules not considered calcified by conventional methods were examined; 118 (31%) proved to be benign, and in 65 of these (55%), unsuspected calcification was demonstrated. In 28 of the 65, definite calcification could be identified on thin-section CT scans by simple inspection of the scans at narrow windows. In the remaining 37, presence of calcification could not be clearly established without comparison with the reference CT number from the calibration phantom. CT was most effective in establishing the benignancy of nodules 3 cm or less in diameter and those with discrete or smooth margins. CT rarely yields a confident diagnosis of benign disease in larger nodules and in those with irregular or spiculated borders. After review of prior spot radiographs, low kilovolt peak spot radiographs, and conventional tomograms, the authors conclude that thin-section CT aided by a reference phantom in equivocal cases should be an integral part of the diagnostic approach to the pulmonary nodule.

We present the radiologic features of four patients proven to have Hermansky-Pudlak syndrome. All four patients had evidence of pulmonary involvement characterized by a progressive, diffuse, bilateral interstitial fibrosis. Extensive bullous changes were seen in one patient. Two patients with evidence of diffuse colitis exhibited an asymmetrical pattern of focal, superficial, and deep ulcerations similar to that of Crohn's disease. The association of these radiographic abnormalities with albinism, ocular abnormalities, bleeding diathesis, and Puerto Rican ancestry establishes the diagnosis

Because of greatly enhanced contrast resolution and the advantages of cross-sectional visualization of lung anatomy, computed tomography (CT) has the potential to add significantly to the conceptualization of parenchymal lung disease. Although the value of CT has been well documented in the detection and characterization of lung nodules, the role of CT has been less clearly defined for other types of lung disease. This report describes the CT appearance of distal air-space disease. As demonstrated by the use of inflated and contrast-injected lungs obtained at autopsy, air-space disease is definable by the following: poorly marginated nodules ranging up to 1 cm in size; coalescence of nodules; air-bronchograms and air-alveolograms; ground-glass opacification; and distinct zonal patterns of distribution, including central and peripheral configurations. These patterns of air-space abnormalities are further refined by review of case material, including examples of air-space disease secondary to aspiration and primary intraalveolar disease, evaluated by the authors over a five-year period.

A series of patients with documented predominantly interstitial pulmonary disease was examined by routine and high-resolution computed tomography (CT) and compared to a series of twenty-one normals. Inspiratory-expiratory lung density measurements were also obtained at predetermined levels. Several basic CT signs of interstitial disease were identified: finely irregular and thickened pleural surfaces; irregular vascular shadows; thickened and irregular bronchial walls making bronchi visible over a longer portion of their course in the lungs; reticular network of lines with three patterns easily distinguishable by the size of their reticular element; hazy patches of increased density of various sizes distinguishable from alveolar filling processes by the fact that vessels can still be visualized through them; and nodules of various sizes. Micronodules are often associated with a small or medium-size reticular network and in most cases seem to represent points of confluence rather than isolated nodules. The hematogenous origin of some nodules can be specifically suggested when feeding vessels are demonstrated on thin-section scans. Nodules associated with a large network of thickened septa are suggestive of lymphangitic carcinomatosis. Inspiratory-expiratory density gradients can be more useful in confirming the diagnosis of interstitial disease than absolute measurements.

The computed tomography (CT) scans of 27 patients with abdominal tuberculosis were reviewed retrospectively to determine the range of abdominal involvement. Most patients had been at increased risk because of intravenous drug abuse, alcoholism, acquired immunodeficiency syndrome (AIDS), cirrhosis, or steroid therapy. The etiologic agent was Mycobacterium tuberculosis in 23 patients and M. avium-intracellulare in four patients with AIDS. In five patients, tuberculosis was limited to the abdomen. CT findings included adenopathy, splenomegaly, hepatomegaly, ascites, bowel involvement, pleural effusion, intrasplenic masses, and intrahepatic masses. Characteristic features were a tendency for adenopathy to prominently involve peripancreatic and mesenteric compartments, low-density centers within enlarged nodes, complex nature of the ascites, and adenopathy adjacent to sites of gastrointestinal tract involvement. Recognition of these manifestations and maintenance of an index of suspicion, especially in patients at risk, should help optimize the correct diagnosis and management of intraabdominal tuberculosis

In 83 patients with acute pancreatitis, the initial computed tomographic (CT) examinations were classified by degree of disease severity (grades A-E) and were correlated with the clinical follow-up, objective prognostic signs, and complications and death. The length of hospitalization correlated well with the severity of the initial CT findings. Abscesses occurred in 21.6% of the entire group, compared with 60.0% of grade E patients. Pleural effusions were also more common in grade E patients. Grades A and B patients did not have abscesses, and none died, regardless of the number of prognostic signs. Abscesses were seen in 80.0% of patients with six to eight prognostic signs, compared with 12.5% of those with zero to two. The use of prognostic signs with initial CT findings results in improved prognostic accuracy. Early CT examination of patients with acute pancreatitis is a useful prognostic indicator of morbidity and mortality