Objectives: Noninvasive criteria for the diagnosis of hepatocellular carcinoma (HCC) in cirrhosis, recommended by the European Association for the Study of Liver (EASL) in 2001 and by the American Association for the Study of Liver Diseases (AASLD) in 2005, have left a number of small liver neoplastic nodules undefined. We designed this prospective study in 2003 with the aims of assessing the diagnostic contribution of vascular contrast-enhanced techniques and investigating the possible additional contribution of superparamagnetic iron oxide magnetic resonance (SPIO-MR) in this setting.
Methods: Between 2003 and 2005, 75 consecutive small (10-30 mm) liver nodules detected at ultrasonography in 60 patients with cirrhosis were prospectively submitted to contrast-enhanced ultrasound (CEUS), helical-computed tomography (helical-CT), and gadolinium magnetic resonance (gad-MR), each blinded to the other. A total of 68 nodules were also studied with SPIO-MR at the same time as gad-MR.
Results: Using the EASL noninvasive criteria, the diagnosis of HCC was established in 44 of 55 (80%) nodules with a final diagnosis of HCC. Gad-MR was the most sensitive technique for detecting the typical vascular pattern. SPIO-MR showed a pattern consistent with HCC in 5 of 10 HCCs, not satisfying the EASL noninvasive criteria, and was negative in 17 of 18 (94.4%) nonmalignant nodules. The review of the present case series according to the AASLD criteria for the noninvasive diagnosis of HCC yielded a sensitivity rate of 81.8%.
Discussion: This study shows that both EASL and AASLD noninvasive recall strategies for nodules of 10-30 mm in the cirrhotic liver, based on the vascular pattern of nodules, have a false-negative rate of approximately 20%. SPIO-MR may increase the diagnostic potential of noninvasive techniques, contributing to the diagnosis of HCC lacking a typical vascular pattern.