Diagnostic Imaging of Hepatocellular Carcinoma - A Pictorial Essay

Abstract

Hepatocellular carcinoma (HCC) is the most common primary liver cancer, which develops mostly in the setting of chronic liver disease. European Association for the Study of the Liver (EASL) and European Organization for Research and Treatment of Cancer (EORTC) prepared guidelines for screening, follow-up and diagnosis of HCC to facilitate decision making and optimize both diagnostic and therapeutic protocols.The review briefly describes etiology, epidemiology and histopathology of HCC and presents EASL-EORTC guidelines for surveillance and diagnosis of HCC. Target population and screening algorithm is presented in the surveillance section. Ultrasound imaging of HCC and the role of contrast enhanced ultrasound are described as well as the value of laboratory tests in screening. Further, radiological features of HCC in multiphase CT and dynamic contrast enhanced MRI and diagnostic criteria are presented. Additionally, the advantages of advanced techniques in MRI such as diffusion weighed imaging and the use of hepatocyte-specific contrast agents are discussed.Lastly, the EASL-EORTC guidelines are compared with the guidelines of the American Association for the Study of Liver Diseases and the Japan Society of Hepatology. Also LI-RADS and the Barcelona Clinic Liver Cancer classification are mentioned.In the near future, due to the ongoing advances in imaging a revision of the guidelines may be expected.

Diagnostic imaging for hepatocellular carcinoma

“…In some cases increased echogenicity may be present due to adipose degeneration. Sometimes the hypoechoic nodule may present a hyperechoic focus which is suggestive of development of HCC within a dysplastic nodule (nodule in nodule phenomenon) [8] .…”

CT-MRI LI-RADS v2017: A Comprehensive Guide for Beginners

“… 9 , 10 Given that approximately 20–40% of lesions smaller than 20 mm in diameter do not show a clear enhancement in the arterial phase, the HBP represents an essential tool to increase MRI diagnostic accuracy, allowing for differential diagnosis between HCC and dysplastic nodules, even when conventional imaging fails. 48 …”

“…Moreover, HBP hypointensity can help to differentiate between hypervascular small HCCs and arteriovenous shunts or focal nodular hyperplasia (FNH)-like lesions, since such observations remain iso- or hyperintense in HBP, in contrast to HCC. 48 Despite HBP hypointensity is a reliable predictor of HCC in at-risk populations, 42 it lacks specificity since it can also be observed in some atypical dysplastic nodules, in all other liver malignancies (metastases included) and in some benign entities like hemangiomas. 49 Furthermore, radiologists should be aware that almost 10% of well-differentiated HCC show HBP hyperintensity, instead of the expected hypointensity.…”

Comparative analysis of three-dimensional volume rendering and maximum intensity projection for preoperative planning in liver cancer

“…Multiphase-enhanced CT and dynamic-enhanced MRI are the most effective imaging techniques to detect hepatic tumors less than 2 cm, but can still underdiagnose 25-30% of cases [ 5 , 6 ]. Advanced imaging is useful for delineating vasculature and calculating volume prior to surgery.…”