Comparison of international guidelines for noninvasive diagnosis of hepatocellular carcinoma.

The aim of this review is to present the similarities and differences between the latest guidelines for noninvasive diagnosis of hepatocelullar carcinoma (HCC) of American Association for the Study of Liver Diseases (AASLD), European Association for the Study of the Liver (EASL), Asian Pacific Association for the Study of the Liver (APASL), and Japanese Society of Hepatology. All the four guidelines defined a typical HCC vascular pattern as the homogeneous hyperenhancement (wash-in) in the arterial phase followed by wash-out in the venous or late phase. The AASLD and EASL guidelines accept only four-phase computed tomography and dynamic contrast magnetic resonance imaging (MRI) for HCC diagnosis, whereas the APASL and Japanese guidelines also accept contrast-enhanced ultrasound (CEUS). Regarding CEUS, the APASL guidelines accept the use of Levovist or Sonazoid as contrast agents, whereas the Japanese guidelines accept only the use of Sonazoid. The AASLD and EASL guidelines recommend using only extracellular contrast agents such as gadolinium for MRI, whereas the APASL guidelines also included the use of super paramagnetic iron oxid-MRI, and the Japanese guidelines recommended the use of gadolinium-ethoxybenzyl-diethylentriamine pentaacetic acid-MRI. The AASLD and EASL guidelines propos a diagnostic algorithm starting from the tumor size, whereas the APASL and Japanese guidelines recommend an algorithm starting from arterial tumor vascularity (hyper- or hypovascular in the arterial phase). In conclusion, important differences exist among the Western and Eastern guidelines for noninvasive HCC diagnosis.