T1 Lung Cancer: Role of Mediastinoscopy and CT in the Diagnosis of Mediastinal Adenopathy

PURPOSE: To evaluate the role of mediastinoscopy and CT in the preoperative nodal evaluation in patients with T1 lung cancer. MATERIALS AND METHODS: Between November 1994 and July 1996, 125 patients underwent thoracotomy and/or mediastinoscopy for surgical treatment of lung cancer. Among them, 35 patients had T1 lung cancer(peripheral lung cancer less than 3cm in diameter) on CT. One patient finally proved to have T4 lung cancer with pleural seeding at thoracotomy. In the remaining 34 patients, pathologic evaluation of mediastinal lymph nodemetastasis was feasible and the results were correlated with CT findings. On CT, nodes larger than 10mm in short-axis diameter were regarded as abnormal. RESULTS: The patients had adenocarcinoma in 12, squamous cellcarcinoma in 11, bronchioloalveolar carcinoma (BAC) in 10, and large cell carcinoma in one. Fifteen among total 478 sampled lymph nodes contained malignant tumor. Six (three with adenocarcinoma, two with squamous cell carcinoma, and one with large cell carcinoma) of 34 patients (18%) had nodal metastasis. With 112 sampled nodes, BAC did not show any nodal metastasis. Sensitivity and specificity of CT for nodal detection were 0% and 100% for2R, 0% and 100% for 4R, 100% and 97 % for 5, 50% and 100% for 7 and 0% and 100% for 10R, respectively. CONCLUSION: T1 lung cancer shows relatively high (18%) prevalence of mediastinal lymph node metastasis. Because small nodesless than 10mm in diameter contain malignancy and CT is insensitive in detection of metastatic nodes,mediastinoscopy is still needed for preoperative nodal evaluation except BAC.

Significance of CT Severity Index in Acute Pancreatitis

PURPOSE: To assess the usefulness of a CT severity index(CTSI) for the evaluation of acute pancreatitis and to correlate it with clinical findings. MATERIALS AND METHODS: We retrospectively evaluated contrast enhanced CT in 34 patients with acute pancreatitis. They were categorized into low-score(0-2), middle-score(3-6), and high-score(7-10) groups according to CTSI points, and those groups were correlated with duration of fasting period, days in hospital morbidity and mortality. We attempted to determine the differences in CTSI between pancreatitis caused by alcohol and by biliary tract disease. RESULTS: Of 34 patients, 11 were placed in the low-score group, 19 in the middle-score group, and 4 in the high-score group. The patients in the middle-score group experienced longer fasting period and stayed longer in hospital than those in the low-score group(p<.05 and p=.08, respectively). Morbidity was 0% in the low-score group, 37% in the middle-score group and 50% in the high-score group. Mortality occurred in two patients in high-score group, only. Alcohol-induced pancreatitis generally showed a higher CTSI and more severe clinical course than pancreatitis caused by biliary tract disease. CONCLUSION: In the evaluation of acute pancreatitis, CTSI can be a useful predictor of its prognosis.

CT Evaluation of the Brain Abscess: Comparison of CT and Pathologic Findings of Brain

PURPOSE: This study was undertaken to correlate the CT and histopathologic findings of abscess wall. MATERIALS AND METHODS: The CT findings of 12 patients with pathologically proven brain abscess were retrospectively analyzed with particular attention to the thickness, smoothness and uniformity of enhancing abscess wall, and the results were correlated with histopathologic findings. RESULTS: Two patients with acute cerebritis showed an isodense ring on non-contrast CT(NCCT), but a true capsule formation could not be identified at pathologic examination. Six other patients with isodense ring on NCCT consisted of early to late cerebritis(3 cases), late cerebritis to early capsule(1 case), early capsule(1 case), and late capsule(1 case). These 6 cases showed ring enhancement on contrast enhanced CT(CECT) and true capsule formation pathologically. There was no isodense ring on NCCT in the remaining four patients. They consisted of early to late cerebritis(2 cases), late cerebritis(1 case), and late cerebritis to early capsule formation(1 case). These also showed ring enhancement on CECT and true capsule formation pathologically. CONCLUSION: We found that it is difficult to predict the exact stage of brain abscess on preoperative CT findings. It is suggested that clinical findings and sequential dynamic CT may provide more detailed informations for evaluation of abscess staging.