Faculty Bibliography

Thin (1.5- and 5.0-mm) section contiguous computed tomographic (CT) scans obtained through the basilar segmental bronchi in 31 patients were reviewed in order to delineate normal anatomy and common variations of lower lobe airways. In each case, the frequency with which individual segmental and subsegmental bronchi were seen was established, as were variations in branching patterns. All basilar segmental bronchi were identified except in one case in which images of the left lung were obscured due to respiratory and cardiac motion. In the right lung, a division into subsegmental bronchi was identified in 84 of 150 (56%) visualized segmental bronchi. Six separate patterns of basilar segmental subdivision were found. In the left lung, subsegmental bronchi were identified arising from 51 of 145 (35%) visualized segmental bronchi. Five separate patterns of bronchial subdivision were found in the left lung. It is concluded that thin-section CT allows precise identification of all basilar segmental bronchi and, consequently, can play a significant role in the cross-sectional evaluation of lower lobe bronchial and parenchymal abnormalities

Over an 18-month period, 11 adults with congenital pulmonary anomalies within the sequestration spectrum, identified either surgically or radiographically by CT and/or angiography, were evaluated with MR. These included seven patients with bronchogenic cysts, two with intralobar pulmonary sequestrations, one with scimitar syndrome, and one with bronchial atresia. In each case, MR showed at least some findings indicative of the correct diagnosis. MR proved especially effective in the detection of abnormal fluid collections (nine cases) and the identification of anomalous vessels (three cases). Fluid collections were easily identified in all cases, including four cases with high-density collections on CT (two with bronchogenic cysts and two with intralobar pulmonary sequestration), especially when single-level, multiecho T2-weighted sequences were obtained. Calculated T2 values ranged from 78 to 439 msec (average, 223 +/- 123 msec). Although T2 values were statistically significant for differentiating fluid from muscle (p = .0012) and fat (p = .0046), they were not sufficiently specific to allow precise fluid characterization. Significant limitations were also apparent, such as an inability to detect alterations in the parenchymal architecture of the lungs (three cases) or intrapulmonary vascularity (one case). Despite this, we conclude that MR may be of considerable value in the assessment of congenital pulmonary anomalies and in select cases obviate more invasive diagnostic procedures

The possible contribution of computed tomography (CT) in the management of patients with solitary pulmonary nodules (SPNs) or masses was reviewed retrospectively in 65 patients undergoing fiberoptic bronchoscopy (FOB). Nodules were evaluated by size, location, surface contour, and the presence in cross-section of a bronchus leading to or contained within the nodule or mass, a 'positive bronchus sign.' Thirty-five lesions were associated with a positive bronchus sign; 21 of 35 (60 percent) were diagnosed endoscopically, (p = .027); of 30 cases with a negative bronchus sign, only ten (30 percent) had a diagnosis made by FOB (p = .034). It is concluded that CT may be of use in the routine evaluation of pulmonary nodules, prior to bronchoscopy, especially in cases for which histologic evaluation is essential, especially to determine the presence or absence of a CT bronchus sign

This report analyzes the detection rate and role of CT in the preoperative evaluation of 90 consecutive, proved cases of colon carcinoma. In this study, the overall detection rate was 84%; however, the rate varied from 68% in unprepared colons to 95% in clean colons that were adequately distended with air. Sensitivity of detection depends mainly on the size of the lesion and the quality of the examination. CT was less sensitive than barium enema in detection, but it had a similar specificity in differentiating neoplastic lesions from inflammatory lesions. On the basis of our criteria of staging, CT evaluation resulted in a sensitivity of 55% for local invasion, 73% for regional nodes, and 79% for liver metastases. Compared with Dukes classification, CT correctly staged 64% of all patients but showed significant variations in staging different groups with lower results in the Dukes A, B, and C patients. CT, however, showed a sensitivity of 81% and a positive predictive value of 100% in detecting Dukes D lesions. In general, although negative CT findings do not help in staging a colonic tumor, positive findings are highly indicative of neoplastic spread. We believe that this feature justifies the use of CT in the preoperative evaluation of colonic tumors

Magnetic resonance phase images are derived from conventional spin-echo (SE) pulse sequences and display properties of proton movement that occurs with blood flow. SE magnitude and phase images were obtained and retrospectively evaluated in 21 patients referred for potential cardiovascular abnormalities in which intracardiac or intravascular signal was detected. Abnormalities included intravascular and intracardiac thrombus, aneurysm, aortic dissection, flow alteration, atherosclerotic disease, and congenital cardiac anomaly. Thrombosis (six cases) was successfully differentiated from flow-related signal (15 cases) by comparing phase images with SE magnitude images; in cases of thrombosis, there was no phase shift in corresponding areas of increased signal intensity. In comparison, SE magnitude signal intensities alone were not an accurate indicator in differentiating thrombus from flow-related enhancement. Because phase images are sensitive for identifying flow, the SE magnitude signal of intravascular tumor or thrombus can be differentiated from that of flow effects with more clinical confidence

Magnetic resonance imaging utilizing spin echo sequences was used to demonstrate cor triatriatum in an 18-year-old boy. Phase map images aided the diagnosis by demonstrating the presence of slowly flowing blood in the accessory atrial chamber. Magnetic resonance is an excellent modality for the noninvasive diagnosis of cor triatriatum

There have been many reports of the ability of CT to distinguish between parenchymal and pleural disease. The purpose of this report is to describe the appearance of seven cases of intraparenchymal fluid-filled air-spaces (bullae or lung cysts) in which the CT findings may resemble those of pleural disease and, thus, cast doubt on the specificity of the established criteria.

This report documents the use of magnetic resonance (MR) in evaluation of intralobar pulmonary sequestration. Because of its distinctive multiplanar capabilities and nonreliance on contrast media to visualize blood vessels, MR can be used to define and characterize the size and course of anomalous arterial feeding vessels. Furthermore, MR can be of value in detecting the presence of mucoid-impacted bronchi within abnormal segments of the lung. It is concluded that in select cases MR may obviate the need for more invasive procedures to establish the diagnosis of pulmonary sequestration

CT findings in 20 consecutive patients with proven esophageal varices are reviewed and analyzed. In 85% of patients, abnormalities were seen involving the esophageal wall and/or periesophageal region. In 65%, findings specific to varices were present: thickening of esophageal wall, a scalloped contour, and intraluminal protrusions enhancing after a contrast bolus injection. These findings were seen alone or in association with periesophageal varices, which were seen in 45% of patients; evidence of portal hypertension with varices in the lesser omentum was present in 95%. CT has a sensitivity similar to barium esophagram but evaluates better the presence and extent of periesophageal varices and portal hypertension. Normal CT does not rule out esophageal varices because small varices may escape detection, particularly in scans done without a contrast bolus injection