Accuracy and disagreement of computed tomography and magnetic resonance imaging for the diagnosis of small hepatocellular carcinoma and dysplastic nodules: role of biopsy

Abstract

Liver macronodules, ranging from benign to low-grade or high-grade dysplastic nodules (LGDNs/HGDNs) and hepatocellular carcinoma (HCC), may develop during chronic liver diseases (CLDs). Current guidelines were recently updated and the noninvasive criteria for the diagnosis of small HCC are based on a single typical radiological pattern and nonconclusive coincidental findings with two techniques. This study aimed to assess the accuracy and disagreements of noninvasive multiphasic examinations for the diagnosis of HCC and dysplastic nodules (DNs) and the role of biopsy. Seventy-four consecutive patients with CLD with ultrasound-detected 1-2-cm nodules underwent, within 1 month, multiphasic computed tomography (CT), magnetic resonance imaging (MRI), and biopsy of the nodule. Median age was 60 years; 33 patients (45%) had hepatitis C virus, 20 (27%) had hepatitis B virus, and 13 (18%) patients had no cirrhosis. Biopsy revealed 47 HCCs, 6 HGDNs, 1 LGDNs, 1 cholangiocarcinoma, and 1 epithelioid hemangioendothelioma. There were no tumors in the other 18 patients. All patients (31 of 31; 100%) who had conclusive coincidental findings (i.e., arterial enhancement and washout) on both examinations had HCC or HGDN (sensitivity, 57%; specificity, 100%). All patients (51 of 51; 100%) who had conclusive findings on at least one of the two examinations had HCC or HGDN (sensitivity, 96%; specificity, 100%). There was a disagreement regarding imaging findings between CT and MRI in 21 of 74 (28%) patients and no washout on both examinations in 23 of 74 patients (31%). In these 44 patients, liver biopsy provided an initial accurate diagnosis.

Conclusion: The noninvasive diagnosis of HCC or HGDN can be obtained if arterial enhancement and washout are found in a single dynamic imaging examination. These findings are frequently discordant on both CT and MRI, supporting the place of biopsy for the diagnosis of small HCCs.