High-Resolution CT in Patients with Chronic Airflow Obstruction: Correlation with Clinical Diagnosis and Pulmonary Function Test

PURPOSE: To determine the utility of HRCT in the diagnosis of chronic airflow obstruction and to correlate the morphologic abnormalities revealed by this modality with functional impairment in patients with chronic air-flow obstruction. MATERIALS AND METHODS:This study involved 80 patients with chronic airflow obstruction who underwent HRCT and a pulmonary function test. Final clinical diagnosis in these patients was determined by a chest physician on the basis of clinical features, bronchoscopy, pulmonary function test, and HRCT. In order to diagnose and determine the extent of areas of decreased attenuation revealed by HRCT (the CT score), the find-ings of HRCT were retrospectively reviewed by two radiologists, who reached a consensus. Clinical and HRCT diagnoses were then compared, and the rate of agreement between them was calculated. The relation-ship between the extent of areas of decreased attenuation revealed by HRCT and by FEV1/FVC was evaluated using Correl 's account and Student 's unpaired t-test. RESULTS: The agreement rate between clinical and HRCT diagnoses was 77.5% (62/80). The rates for bronchiec-tasis (88.9%, 24/27), emphysema (93.9%, 31/33), and bronchiolitis obliterans (100%, 6/6) were considerably higher than those for chronic bronchitis and bronchial asthma. The correlation rate between CT score and FEV1/FVC was significant in bronchiectasis (p0.05). CONCLUSION: HRCT is valuable in the diagnosis and prediction of physiologic impairment in patients with bronchiectasis and bronchiolitis obliterans, but has limited value in those with emphysema, chronic bronchitis or asthma.

CT Features of Malignant Hepatic Tumors: the Significance of Capsular Retraction

PURPOSE: To evaluate the prevalence of capsular retraction in malignant hepatic tumors and the factorsinvolved. MATERIALS AND METHODS: Between January 1994 and December 1996, we retrospectively reviewed the CT scansof 152 patients with pathologically-proven, peripherally-located, malignant hepatic tumors. We evaluated size,site, portal and hepatic venous obstruction, bile duct dilatation, and liver atrophy in 18 cases involvingcapsular retraction. RESULTS: The overall prevalence of capsular retraction among malignant hepatic tumors was18/152(12%) ; the prevalence was 9/129(7%) in hepatocellular carcinoma, 6/14(43%) in cholangiocarcinoma and3/9(33%) in metastatic cancer ; among cases of cholangiocarcinoma and metastatic cancer, the prevalence washigh(p <0.05). Portal venous obstruction was seen in six patients with hepatocellular carcinoma (a high incidence ;p=0.041) and one with cholangiocarcinoma. Hepatic venous obstruction was demonstrated in one patient withhepatocellular carcinoma and one with cholangiocarcinoma. Among cholangiocarcinoma patients, bile duct obstructionwas seen in four and liver atrophy in three, but among metastatic cancer cases there were no similar findings. CONCLUSION: The main factors causing capsular retraction were portal venous obstruction in hepatocellularcarcinoma and bile duct obstruction and liver atrophy in cholangiocarcinoma.

CT Findings of Tumor and Mature Cystic Teratoma

PURPOSE: A tumor and mature ovarian cystic teratoma rarely coexist, but since it may affect treatment andprognosis, appropriate pre-surgical diagnosis is important. The purpose of this study was to evaluate thedifference in CT findings between a tumor coexisting with a mature ovarian cystic teratoma and a simple matureovarian cystic teratoma. MATERIALS AND METHODS: CT scans of seven cases of tumor coexisting with mature ovariancystic teratoma were reviewed. In each case, size, margin, nature, septation, solid portion, ascites, invasion,and metastasis were analysed. RESULTS: Coexistent tumors were histopathologically diagnosed as squamous cellcarcinoma in three patients, carcinoid in three, and fibrothecoma in one. In contrast with a simple matureteratoma, a tumor coexisting with a mature cystic teratoma developed in older patients and had a more solidportion, which showed contrast enhancement but did not show calcification or a fat component. Where a tumor andmature cystic teratoma coexisted, ascites and the invasion of adjacent structures were also common. CONCLUSION: If, in an older patient, CT scanning reveals an ovarian cystic tumor with a large solid portion but nocalcification or fat, coexistent tumor should be suspected.

Differential Diagnosis of Solitary Pulmonary Nodule: Chest Radiography vs CT

PURPOSE: The purpose of this study was to compare the diagnostic accuracies of chest radiographs and chest CTin the diagnosis of a solitary pulmonary nodule(SPN), and to determine the role of CT and CT findings which aid inthe differential diagnosis of nodules. MATERIALS AND METHODS: A retrospective study was done on 54 patients inwhom SPN was found on chest radiographs and chest CT was carried out. The study involved 25 benign and 29 malignant nodules, confirmed histopathologically and clinically. Chest radiographs and CT scans were reviewed separately in randomized order by two chest radiologists who for each film listed the three most likely diagnose sin descending order. The radiologists recorded the confidence value of the most probable diagnosis, and also the marginal and internal characteristics of nodules and their size, as nodules seen on chest CT scans. RESULTS: Diagnostic rates in the differential diagnosis of benign and malignant nodules were 65.7% by radiography and 77.8% by CT. Correct first-choice diagnosis was by radiography in 30.6 % of cases, and by CT in 41.7%. Using radiographs, and the correct diagnosis was among the top-three choices in 61.1% of cases ; with CT, the corresponding figure was 76.8%. Overall, a confident diagnosis was reached more often with the CT(41.7%) than with the chest radiograph(21.4%) ; diagnaotic accuracy was 60.0% and 52.2%, respectively. CT findings which imply abenign nodule include smooth margins and diffuse internal calcifications, whereas marginal lobulations, air-bronchograms, internal low density without cavitation, eccentric calcifications, and large size suggest malignancy. We faund that CT findings such as well-defined margins, spiculations, pleural tail or internal homogeneity did not contribute in the differentiation between benign and malignant nodules. CONCLUSION: CT issuperior to chest radiography in the differential diagnosis of the solitary pulmonary nodule. Using CT, diagnosis was accurate and made with a high level of confidence, especially with the application of CT findings which aid inthe differential diagnosis of nodules.