Andrea Laghi, MD Riccardo Iannaccone, MD Plinio Rossi, MD Iacopo Carbone, MD Riccardo Ferrari, MD Filippo Mangiapane, MD Italo Nofroni, MSc Roberto Passariello, MD Index terms: Computed tomography (CT), multi– detector row, 761.12114 Liver neoplasms, 761.323 Liver neoplasms, CT, 761.12114 Published online before print 10.1148/radiol.2262012043 Radiology 2003; 226:543–549 Abbreviation: HCC = hepatocellular carcinoma 1 From the Departments of Radiology II (A.L., R.I., I.C., R.F., F.M., R.P.), Ra- diology III (P.R.), and Experimental Medicine and Pathology (I.N.), Uni- versity of Rome-La Sapienza, Poli- clinico Umberto I, Viale Regina Elena 324, 00161 Rome, Italy. Received De- cember 13, 2001; revision requested February 22, 2002; revision received April 18; accepted June 5. Address correspondence to A.L. (e-mail: andrea.laghi@uniroma1.it). Author contributions: Guarantor of integrity of entire study, R.P.; study concepts and design, A.L., R.I., I.C., R.F., F.M.; literature research, R.I., R.F., F.M.; clinical studies, R.I., I.C., R.F., F.M.; data acquisition, R.I., I.C.; data analysis/interpretation, A.L., P.R., R.P.; statistical analysis, R.I., I.N.; manuscript preparation, A.L., R.I.; manuscript definition of intellectual content, A.L., R.I., P.R., R.P.; manu- script editing, A.L., R.I., R.P.; manu- script revision/review, P.R.; manu- script final version approval, P.R., R.P. © RSNA, 2002 Hepatocellular Carcinoma: Detection with Triple-Phase Multi–Detector Row Helical CT in Patients with Chronic Hepatitis 1 PURPOSE: To evaluate whether the use of two arterial phase image acquisition series, when combined with portal venous phase imaging at multi– detector row helical computed tomography (CT), would be superior enough to use of a single arterial phase image acquisition series to warrant the increased radiation dose. MATERIALS AND METHODS: Multi– detector row CT was performed in 77 pa- tients with 140 foci of hepatocellular carcinoma (HCC). A triple-phase protocol that included an early arterial phase, a late arterial phase, and a portal venous phase was performed. Images were analyzed separately by three radiologists to document the presence and number of HCC nodules. Separate reading sessions were performed for images from the early arterial phase, images from the late arterial phase, images from both arterial phases combined, and images from all three phases. Sensitivity and positive predictive values were calculated for each reading session. RESULTS: The average sensitivity and positive predictive values, respectively, for the detection of HCC were 48.5% and 96.4% for early arterial phase images, 87.1% and 94.0% for late arterial phase images, 87.1% and 94.0% for images from both arterial phases, and 88.5% and 93.4% for images from all three phases. Analysis of images from both arterial phases together yielded no improvement in either sensi- tivity or positive predictive value compared with analysis of late arterial phase images alone. Analysis of the combination of late arterial and portal venous phase images resulted in the highest sensitivity value. CONCLUSION: The acquisition of images during two arterial contrast phases does not provide additional benefit over timed conventional biphasic CT technique. © RSNA, 2002 In non-Asian populations, hepatocellular carcinoma (HCC) usually develops in patients with hepatic cirrhosis (1). The detection of HCC in patients with cirrhosis has long been considered a technical challenge because cirrhosis alters both liver parenchymal charac- teristics (through fibrosis, creation of regenerative nodules, and fatty infiltration) and vascularization (through portal hypertension and the creation of arterial–portal venous shunts) (1–3). Most HCCs are hypervascular lesions that typically enhance during the phase of maximum hepatic arterial enhancement (the so-called hepatic arterial dominant phase) (4,5). Therefore, such lesions have often been difficult to detect with conventional computed tomography (CT) of the liver, in which only portal venous phase imaging was performed because of the long scanning time. During the past decade, the introduction of helical CT technology has made biphasic scanning feasible. In particular, results of several studies have demonstrated that use of a two-phase approach, with acquisition of images in the hepatic arterial dominant phase as well as in the portal venous phase, greatly improves the detection of HCC (1,4,6 –9). At present, with the advent of multi– detector row helical CT scanners, it is possible to 543 R adiology