Findings in Multidetector Computed Tomography in the diagnosis of hepatocellular carcinoma in patients with cirrhosis and correlation with pathology of liver explants

Hepatocellular carcinoma (HCC) is the fifth most common neoplasm in men and the seventh in women, with a five-year survival rate of approximately 12%. The main predisposing factor for the development of HCC is cirrhosis1, 2. In Argentina, the main etiologies for cirrhosis are alcoholism or hepatitis C virus and, with a lower prevalence, the hepatitis B virus or cryptogenic cirrhosis3. Surgery is the best therapeutic option for HCC because of its lower rate of local recurrence and increased survival time. Surgical therapies include resection and transplantation: while the former is indicated for a small percentage of patients with small single tumors (< 2 cm) with favorable anatomic location and relative preserved liver function (Child-Pugh class A), for all other patients liver transplantation is the surgical therapy of choice 4-6. Given the growing demand for liver transplantation, an appropriate allocation of organs to patients on waiting lists is crucial. This choice is based on the Model for End-Stage Liver Disease (MELD) model 7,8, which awards additional score to patients who meet the Milan criteria for the diagnosis of HCC. For this reason, the proper identification and staging of a tumor has a considerable impact on organ allocation and Abstract Objectives: To describe the imaging behavior of hepatocellular carcinoma in cirrhotic patients using a dynamic multidetector computed tomography (MDCT) technique, and to correlate these findings with histological tumor grades. Materials and methods: A retrospective, descriptive observational study was conducted to evaluate 51 nodules in 32 liver transplant patients diagnosed with liver cirrhosis. The pathology of liver explants was used as reference. Nodules with hepatocellular carcinoma histopathology were retrospectively analyzed by computed tomography scans performed pretransplant. Using a dynamic multidetector computed tomography technique, we evaluated the most common imaging behavior reported in the literature: arterial phase enhancement, washout, capsule, and intratumoral arterial vessels. Results: Forty-six of 51 (90%) tumors showed arterial enhancement. Of the 46 tumors with arterial enhancement, 39 (85%) had washout in portal-late phase. Five of 51 (10%) were hypovascular. Twenty-two of 51 (43%) had capsule, and 12 of 51 (24%) showed intratumoral arterial vessels. The most frequent combination of findings was the association between arterial phase enhancement and washout in the portal venous-delayed phase (39 of 51 tumors or 76%). The most frequent histological grade was grade II (35 of 51 tumors or 69%). Statistically significant relationships were found between histological grade tumors and imaging behavior, hypovascular and arterial phase enhancement. Conclusion: In our population, arterial enhancement with washout in the portal venous and/ordelayed phases was observed in most tumors. Our results are consistent with previous reports, demonstrating the high reliability of this imaging pattern for the diagnosis of hepatocellular carcinoma.