Faculty Bibliography

PURPOSE: The accessory cardiac bronchus is a rare congenital anomaly of the tracheobronchial tree that arises from the medial wall of the bronchus intermedius. This report documents the computed tomographic (CT) appearance of this anomaly. MATERIALS AND METHODS: Six patients with this anomaly were identified. All six underwent CT; three underwent correlative bronchoscopy, and one had both bronchoscopic and surgical confirmation. RESULTS: In all six cases, a distinct airway could be identified originating from the medial wall of the bronchus intermedius. Associated lung parenchymal tissue was identified in four cases, while in three cases a discrete soft-tissue mass was seen, presumably representing vascularized bronchial or vestigial parenchymal tissue. In two cases, the lumen of the airway was filled with debris. CONCLUSION: Recognition of this anomaly is important, as associated clinical complications, including recurrent episodes of both infection and hemoptysis, may be anticipated in a small percentage of patients

To evaluate the findings on thin-section computed tomographic (CT) scans in desquamative interstitial pneumonia (DIP), the CT scans from 22 patients aged 22-71 years (mean age, 43 years) were reviewed. In all patients, DIP was proved with open-lung biopsy performed 1 day to 17 months before or after examination with CT (median interval, 1.5 months). The lungs were divided into three zones (upper, middle, and lower); each zone was evaluated separately. The predominant finding was the presence of areas of ground-glass attenuation that involved the middle and lower lung zones in all patients and the upper lung zones in 18 patients (82%). Such areas had a lower lung zone predominance in 16 patients (73%) and a predominantly peripheral distribution in 13 patients (59%). Irregular lines of attenuation suggestive of fibrosis were seen in 11 patients (50%) and cystic changes, in seven patients (32%). The distribution of abnormalities in DIP is similar to that seen in usual interstitial pneumonia (UIP), but the greater extent of ground-glass attenuation and the paucity of cystic changes in DIP should enable distinction from UIP in most patients.

The occurrence of bronchiectasis has only rarely been noted among the protean manifestations of HIV infection in the lungs. We retrospectively identified bronchiectasis on CT scans in 12 HIV + and/or AIDS patients in the absence of either documented mycobacterial infection or a history of prior recurrent pyogenic infection. Pneumonitis was documented in 10 of 12 cases. In eight cases, bronchiectasis was associated with episodes of pyogenic infection; four of these patients also had documented opportunistic infections, including three cases of Pneumocystis carinii pneumonia (PCP). Two patients had infection due solely to PCP. In two cases, bronchiectasis was found in association with one case each of lymphocytic interstitial pneumonitis and nonspecific interstitial pneumonitis, respectively. Although the true incidence of bronchiectasis in this population remains to be established, in our experience bronchiectasis should be considered among the varied pulmonary manifestations of HIV infection. Furthermore, the seemingly rapid development and extent of bronchiectasis in this population suggest an accelerated form of the disease

CT is the imaging method of choice after standard chest radiography for examining patients with suspected bronchiectasis. In most institutions throughout the world, CT has largely eliminated the need for bronchography in the diagnosis of bronchiectasis. Nonetheless, controversy persists concerning the overall accuracy of CT. In an effort to improve overall diagnostic accuracy, we review the wide range of CT appearances of this protean disorder, and emphasize potential problems and technical pitfalls that may arise in routine clinical imaging

To meaningfully evaluate factors determining the overall accuracy of computed tomography (CT) for identifying pulmonary nodules, computer-generated nodules were superimposed on normal CT scans and interpreted independently by three experienced chest radiologists. Variables evaluated included nodule size, shape, number, density, location, edge characteristics, and relationship to adjacent vessels, as well as technical factors, including slice thickness and electronic windowing. The overall sensitivity in identifying nodules was 62% and the specificity was 80%. On average, the observers identified 56, 67, and 63% of nodules on 1.5-, 5-, and 10-mm-thick sections, respectively (p = 0.037). Nodules were more difficult to identify on 1.5-mm-thick sections. On average, observers identified 1, 48, 82, and 91% of nodules < 1.5, < 3, < 4.5, and < 7 mm in diameter, respectively (p < 0.001). Other factors that made a significant contribution (p < 0.01) in identifying nodules, as determined by linear discriminant function analysis, included nodule location, angiocentricity, and density. We concluded that computer-generated nodules can be used to assess a large number of imaging variables. We anticipate that this approach will be of considerable utility in assessing the accuracy of interpretation of a wide range of pathologic entities as well as in optimizing three-dimensional scan protocols within the thorax

The authors describe the radiographic appearance of the left atrial catheter, a widely used postsurgical intracardiac device. Recognition of the characteristic appearance of this catheter should be of value in detection of potential complications, including line fracture with resultant retention and/or embolization, infection, prosthetic valve dysfunction, and even cardiac tamponade

High-resolution CT (HRCT) and chest radiographs were compared in nine patients with miliary lung disease. In all cases, miliary disease was documented to be infectious in etiology; six of these patients proved to be human immunodeficiency virus (HIV) positive. A mixture of both sharply and poorly defined 1-3 mm nodules was seen in all cases, many of the latter having an appearance indistinguishable from airspace nodules. Other features attributable to the presence of nodules included nodular interlobular septae, nodular irregularity of vessels, subpleural dots, and studded fissures. Diffuse intra- and interlobular septal thickening also proved common, seen in all but one case (91%). Based on limited HRCT-pathologic correlation, CT findings appear primarily to be due to granulomatous foci developing in a seemingly random distribution involving both pulmonary airspaces as well as the interstitium. It is concluded that in the appropriate clinical setting this constellation of findings is characteristic of miliary disease; the role of HRCT especially in the early diagnosis of miliary disease in HIV positive patients remains to be determined prospectively

To date, few reports have attempted to correlate plain radiographic findings with computed tomography (CT) in assessing pulmonary disease in patients who have acquired immunodeficiency syndrome (AIDS). This report focuses on the most common pulmonary manifestations, with particular emphasis placed on those entities for which there is a potential role for CT. This includes identification of occult disease, especially the early diagnosis of Pneumocystis carinii pneumonia, as well as identification of unsuspected lung abscesses and cavities; characterization of diffuse parenchymal disease in patients who have abnormal radiographs; identification and characterization of mediastinal lymphadenopathy, especially in differentiating between neoplastic and non-neoplastic causes; and finally, use of CT to perform CT-guided transthoracic needle biopsies