Solitary Pulmonary Nodule on Helical Dynamic CT Scans: Analysis of the Enhancement Patterns Using a Computer-Aided Diagnosis (CAD) System

OBJECTIVE: We wanted to investigate the usefulness of a computer-aided diagnosis (CAD) system in assisting radiologists to diagnosis malignant solitary pulmonary nodules (SPNs), as compared with diagnosing SPNs with using direct personal drawing. MATERIALS AND METHODS: Forty patients with SPNs were analyzed. After the pre-contrast scan was performed, an additional ten series of post-contrast images were obtained at 20-second intervals. Two investigators measured the attenuation values of the SPNs: a radiologist who drew the regions of interest (ROIs), and a technician who used a CAD system. The Bland and Altman plots were used to compare the net enhancement between a CAD system and direct personal drawing. The diagnostic characteristics of the malignant SPNs were calculated by considering the CAD and direct personal drawing and with using Fisher's exact test. RESULTS: On the Bland and Altman plot, the net enhancement difference between the CAD system and direct personal drawing was not significant (within +/- 2 standard deriation). The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy of diagnosing malignant SPNs using CAD was 92%, 85%, 75%, 96% and 88%, respectively. The sensitivity, specificity, PPV, NPV and accuracy of diagnosing malignant SPNs using direct drawing was 92%, 89%, 79%, 92% and 88%, respectively. CONCLUSION: The CAD system was a useful tool for diagnosing malignant SPNs.

Intraperitoneal Hemorrhage Due to Spontaneous Rupture of Hepatocellular Carcinoma: Comparisons of Tranarterial Oily Chemoembolization and Simple Embolization with Gelfoam

PURPOSE: To compare the safety and effectiveness of transarterial oily chemoembolization (TOCE) and transar-terial embolization (TAE) with Gelfoam in cases of ruptured hepatocellular carcinoma (HCC), and to describe the most important prognostic factors involved in emergency embolization. MATERIALS AND METHODS: Forty-two consecutive patients with spontaneously ruptured HCC underwent emergency TOCE (n = 22) or TGE (n = 20). In the TOCE group, Lipiodol (3 -10 cc), Adriamycin (20 -50 mg), and Mitomycin (2 -10 mg) were used, and these were followed by blockade of the hepatic arterial flow with gelatin sponge particles. In the TAE group, patients underwent only Gelfoam embolization. Using the Kaplan-Meier method, survival time from the time of embolization was estimated, and to analyze prognostic factors, Cox 's proportional hazard regression model was used. RESULTS: Successful hemostasis was achieved in 41 patients (97.6%). Mean survival time was 201 and 246 days in the TOCE and TAE group, respectively, but the difference was not tatistically significant (p > 0.05). Five of the TOCE group (22.7%) and three of the TAE group (15.0%) died of hepatic failure. Analysis of the prognostic factors showed that portal vein involvement by the tumor was the most important factor influencing survival. CONCLUSION: Although TOCE and TAE effectively controlled hemorrhaging from a ruptured HCC, the procedures involve a high risk of hepatic failure. Their goal should, therefore, be solely to achieve hemostasis, and thus decrease parenchymal injury.