Faculty Bibliography

PURPOSE: To evaluate assessment of diffuse lung disease with helical computed tomography (CT) and maximum intensity projection (MIP) and minimum intensity projection images. MATERIALS AND METHODS: Six patients with suspected lung disease (the control group) and 20 patients with documented disease underwent axial helical CT through the upper and lower lung fields. Findings on the MIP and minimum intensity projection images of each helical data set were compared with findings on the thin-section scan obtained at the midplane of the series. RESULTS: Owing to markedly improved visualization of peripheral pulmonary vessels (n = 26) and improved spatial orientation, MIP images were superior to helical scans to help identify pulmonary nodules and characterize them as peribronchovascular (n = 2) or centrilobular (n = 7). Minimum intensity projection images were more accurate than thin-section scans to help identify lumina of central airways (n = 23) and define abnormal low (n = 15) and high (ground-glass) (n = 8) lung attenuation. Conventional thin-section scans depicted fine linear structures more clearly than either MIP or minimum intensity projection images, including the walls of peripheral, dilated airways (n = 3) and interlobular septa (n = 3). MIP and minimum intensity projection images added additional diagnostic findings to those on thin-section scans in 13 (65%) of 20 cases. CONCLUSION: MIP and minimum intensity projection images of helical data sets may help diagnosis of a wide spectrum of diffuse lung diseases

After graft repair of an ascending aortic aneurysm, a patient was seen by us with a chest x-ray film indicating a retained foreign body. Mediastinal exploration had been unrevealing. Transesophageal echocardiography demonstrated the nature and exact location of the foreign body and therefore was instrumental in directing its retrieval

PURPOSE: To identify characteristic computed tomographic (CT) findings in unusual pulmonary lymphoproliferative disorders seen in adults with the human immunodeficiency virus (HIV) or acquired immunodeficiency syndrome (AIDS). MATERIALS AND METHODS: The authors retrospectively reviewed the CT scans and pathologic specimens from nine patients with pulmonary lymphoproliferative disorders. CT scans were evaluated for nodules, reticulation, areas of ground-glass attenuation, consolidation, and bronchial disease. Changes seen in pathologic specimens were classified as consistent with classic lymphocytic interstitial pneumonitis (LIP), mucosa-associated lymphoid tissue lymphoma (MALTOMA), or atypical lymphoproliferative disorder (ALD). Immunopathologic results were reviewed when available. RESULTS: Eight patients had AIDS. Five patients had classic LIP. One patient had MALTOMA, and three patients had ALD. Altogether, 2-4-mm-diameter nodules were the predominant CT finding in eight patients; these were peribronchovascular in four patients. The presence of interstitial nodules correlated with the pathologic finding of nodular disease in seven patients. CONCLUSION: Familiarity with these AIDS-related disorders and their CT appearance should assist in the differential diagnosis

PURPOSE: To identify characteristic features of cytomegalovirus (CMV) pneumonitis at computed tomography (CT), particularly markers that may help differentiate CMV from Pneumocystis carinii pneumonia. MATERIALS AND METHODS: Bronchoalveolar lavage (BAL) and biopsy results in 21 patients with acquired immunodeficiency syndrome, cytopathologic evidence of CMV infection without other infections, and available CT scans were retrospectively evaluated. CT findings were correlated with radiographic and pathologic findings when available. RESULTS: BAL findings were positive for CMV in only six cases, 13 patients had extrathoracic CMV infection, and 10 had Kaposi sarcoma. CT findings included ground-glass attenuation, dense consolidation, bronchial wall thickening or bronchiectasis, and interstitial reticulation without air-space disease (12 patients had discrete pulmonary nodules or masses). Biopsy revealed air-space disease as the dominant process in eight cases. Histopathologic findings correlated well with CT appearances. CONCLUSION: CMV pneumonitis should be suspected in patients with either extrathoracic CMV or documented Kaposi sarcoma, especially when radiographic or CT evidence of pulmonary nodules or masses exists

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

The progression of lung disease in patients with cystic fibrosis (CF) was evaluated with chest radiography. The severity and extent of the various radiographic changes were scored with the Chrispin or the Birmingham method, which involves the use of imprecise and subjective terms, such as line shadows, large pulmonary shadows, and nodular cystic lesions. Although computed tomography (CT) has been shown to be helpful in the evaluation of lung disease in CF, no scoring system or other objective criteria have been developed for the evaluation of the wide range of pulmonary changes in these patients. A CT scoring system was devised that incorporates all of the changes seen in the lungs of patients with CF. Such a scoring system may facilitate objective evaluation of existing and newly developed therapeutic regimens and may be a valuable tool in the preoperative evaluation of patients being considered for lobectomy or bullectomy and in the selection of patients for lung transplantation.