Non-invasive diagnosis of hepatocellular carcinoma ≤ 2 cm in cirrhosis. Diagnostic accuracy assessing fat, capsule and signal intensity at dynamic MRI

Abstract

Background & aims: To prospectively assess the diagnostic accuracy of the incorporation of additional magnetic resonance imaging (MRI) parameters in those based on contrast enhancement pattern for the diagnosis of solitary nodules between 5 and 20mm, detected during surveillance in patients with cirrhosis.

Methods: Between November 2003 and January 2010, we prospectively included 159 cirrhotic patients with a newly detected solitary nodule between 5 and 20mm in diameter by screening ultrasonography (US). Hepatic MRI and fine-needle biopsy were performed in all patients.

Results: Final diagnoses were hepatocellular carcinoma (HCC) (n=103), other malignant lesions (intrahepatic cholangiocarcinoma/metastases) (n=4), and benign lesions (n=52). The specific enhancement pattern (arterial enhancement followed by washout) yielded a sensitivity and specificity of 58.3% and 96.4%, respectively. Peritumoral capsule was present in 43 HCC and in 2 non-HCC lesions. Intralesional fat was detected in 24 nodules; 5 nodules were non-HCC. Finally, the presence of both capsule and fat was observed in 10 cases, all of them HCC (100% specificity), but all of them also displayed the specific enhancement pattern, thus adding no sensitivity or specificity.

Conclusions: Conclusive non-invasive diagnosis of HCC in cirrhosis should be based only on the contrast enhancement pattern, while other characteristics at MRI do not increase the diagnostic accuracy.