Diagnosis of diaphragmatic trauma with helical CT in a swine model.

OBJECTIVE: The purpose of this study was to determine whether diaphragmatic injury can be accurately diagnosed with helical CT in a swine model. The hypothesis of our study was that thin-section helical CT with sagittal and coronal reformations can reliably detect injury of the diaphragm. MATERIALS AND METHODS: The study was performed in a swine model because of the similarity of the swine thorax to the human thorax. Ten swine had a limited abdominal helical CT (enteral contrast; 3-mm collimation; pitch, 1) before and after surgical creation of a 6-cm posterolateral laceration in the left hemidiaphragm. A repeat scan was obtained after 5 cm of gastric fundus was sutured through the laceration. The gastric fundus was used because it is the most commonly herniated viscus in human diaphragmatic injury. No IV contrast was used. Control, laceration, and herniation scans were reconstructed with 1.0-mm overlap and reformated in axial, sagittal, and coronal planes. Three observers scored each reformation as control or injury (defined as laceration or herniation) in a blinded and randomized fashion. RESULTS: Using helical CT, the observers were able to distinguish diaphragmatic injury from controls (p < .0001). The sensitivity and specificity were 92% and 87%, respectively, for sagittal reformations; 85% and 87%, respectively, for coronal reformations; and 73% and 80%, respectively, for axial reformations. Sagittal reformations proved superior to coronal or axial reformations (p = .01). The results were independent of individual observers: We found no significant difference in accuracy among the three observers. CONCLUSION: Helical CT can accurately detect diaphragmatic injury in a swine model.

High-resolution computed tomography sampling for detection of asbestos-related lung disease.

RATIONALE AND OBJECTIVES: We determined whether a limited number of high-resolution computed tomography (HRCT) scans will effectively screen for interstitial lung disease (ILD) in a population of individuals exposed to asbestos. METHODS: We retrospectively reviewed the computed tomography studies of 49 patients exposed to asbestos. HRCT in the supine and prone positions had been performed at specifically preselected levels. Two teams of thoracic radiologists evaluated, on separate occasions: (1) all images, (2) prone images only, and (3) a single prone image through the lung bases for the presence of diffuse ILD. RESULTS: A relatively high level of accuracy was obtained with a single prone scan. However, improvement to 95% or better was found when additional prone images were used. CONCLUSION: A screening study for ILD, in this case patients exposed to asbestos, may be performed by preselected prone HRCT images only. The ease and decreased time of performing the procedure make screening relatively large patient groups for ILD more feasible.

CT quantification of interstitial fibrosis in patients with asbestosis: a comparison of two methods.

OBJECTIVE: The likelihood of interstitial lung disease being detected on high-resolution CT scans and having functional significance is often related to the severity of the disease. The extent and severity of the abnormalities seen on high-resolution CT are usually assessed subjectively. This study was undertaken to investigate whether a subjective semiquantitative scoring method or a method using a cumulation of the different high-resolution CT features of asbestosis were comparable in suggesting asbestosis in a group of patients with histopathologic confirmation of disease. A secondary objective was to compare the results of these two high-resolution CT methods with chest radiographs in the same population. MATERIALS AND METHODS: This study group consisted of 24 patients and six lungs obtained at autopsy. Histopathologic asbestosis was present in 25 of the 30 patients or lungs. The patients or lungs were imaged using selected high-resolution CT scans. The high-resolution CT scans were assessed in two ways. One used a subjective semiquantitative extent and severity score consisting of four levels of severity, while the other was a cumulative score adding the different types of high-resolution abnormalities in asbestosis. The commonest high-resolution CT abnormalities in the cases with confirmed asbestosis were interstitial lines (84%), parenchymal bands (76%), and architectural distortion of secondary pulmonary lobules (56%). Subpleural lines and honeycombing were less frequent. The histopathologic severity of asbestosis was independently graded on a four-point scale. Chest radiographs, when available, were classified according to the International Labor Organization (ILO) classification of pneumoconioses. RESULTS: With the subjective semiquantitative high-resolution CT severity score, asbestosis was suggested in 16 (64%) instances, all with disease. With the cumulative method, any one type of abnormality was present in 88% of cases with asbestosis, two types in 78%, and three in 56%. However, to include only cases with asbestosis, three different abnormalities had to be present. The high-resolution CT scans were normal or near normal in five instances of asbestosis. Chest radiographs using the ILO classification predicted asbestosis with a lesser frequency than high-resolution CT in this selected population. CONCLUSION: We conclude that a subjective semiquantitative grading system of the extent and severity of asbestosis and a method using a cumulative addition of the different findings in asbestosis give similar results in suggesting the presence of disease. Thus, for the high-resolution CT detection of asbestosis, a combination of the cumulative number of different findings and an assessment of the extent and severity of the abnormalities could be complimentary. We also conclude that asbestosis can be present histopathologically with a normal or near normal high-resolution CT scan.

Upper and middle lobe bronchoalveolar lavage to diagnose Pneumocystis carinii pneumonia.

Pneumocystis carinii pneumonia (PCP) remains the most common lethal opportunistic pulmonary infection in patients infected with the human immunodeficiency virus (HIV). Although the use of prophylactic inhaled pentamidine has effectively reduced the frequency of primary and recurrent episodes of PCP, the aerosolization of pentamidine may have altered the localization of active PCP, resulting in more upper lobe disease. The distribution of disease may have also affected the diagnostic accuracy of standard bronchoalveolar lavage of the middle lobe, with a reduction in sensitivity from about 90 to 65%. In retrospective surveys of patients from our institution, Steiger and Fahy found that pooled multiple-lobe radiographic site-directed bronchoalveolar lavage resulted in diagnostic sensitivities of 91 and 100%, respectively. We performed a follow-up prospective study of 38 consecutive patients on aerosolized pentamidine in whom we lavaged both the middle lobe and an upper lobe. We found that bilobar lavage including routine lavage of an upper lobe increases the diagnostic sensitivity of bronchoalveolar lavage alone to 95% compared with 65% if lavage is performed only in the middle lobe (p < 0.05). Radiographic studies demonstrate a concordant increase in exclusive or predominant upper lobe disease in patients on aerosolized pentamidine, but our results indicate that PCP is recovered more frequently from the upper lobe regardless of the radiographic appearance. We conclude that all patients on prophylactic inhaled pentamidine should undergo bilobar lavage with the inclusion of an upper lobe in the initial evaluation of possible PCP. The diagnostic sensitivity of 95% makes bilobar bronchoalveolar lavage an acceptable sole initial diagnostic modality without the need for initial transbronchial lung biopsy.

Endobronchial vascular occlusion coils for control of a large parenchymal bronchopleural fistula.

Angiographic occlusion coils placed endobronchially under fluoroscopic guidance succeeded in controlling a large parenchymal bronchopleural fistula after failure of surgical treatment and transbronchoscopic fibrin glue application.