Michele Di Martino MD,PhD, Presenter: Nothing to Disclose

Michele Anzidei MD, Abstract Co-Author: Nothing to Disclose

Fulvio Zaccagna MD, Abstract Co-Author: Nothing to Disclose

Luca Saba MD, Abstract Co-Author: Nothing to Disclose

Carlo Catalano MD, Abstract Co-Author: Nothing to Disclose

To evaluate radiological findings and diagnostic accuracy of gadoxetic acid magnetic resonance imaging (MRI) in the evaluation of small (≤2 cm) regenerative nodules (RN), dysplastic nodules (DN) and well-differentiated hepatocellular carcinomas (HCCs).

Sixty-two cirrhotic patients, with 107 focal liver lesions were prospectively recruited. MR examinations were performed with a 3T magnet (Discovery MR750; General Eletric Systems). The MRI study protocol included T1-weighted and T2-weighted pre-contrast sequences and 3D spoiled gradient-echo T1-weighted post-contrast sequences Gd-EOB-DTPA-enhanced obtained during the arterial, portal-venous and equilibrium phases ≈25 s, 70 s 180 s and after 20 m. All lesions (33 RN, 29 DN and 45 HCCs) were pathologically confirmed. One radiologist not involved in the datasets analysis reported the signal intensity characteristics of each lesion. Two radiologists blinded to clinical and pathological information evaluate radiological dataset images. Sensitivity, specificity and diagnostic accuracy were considered for statistical analysis.

Regenerative nodules usually show enhancement during the arterial phase without wash-out sign during portal-venous and delayed phase. Dysplastic nodules tend to do not show enhancement during the arterial phase and present wash-out on delayed phase. Well-differentiated HCCs very often show typical vascular pattern (wash-in and wash-out) and low signal intensity during the hepatobiliary phase. According to the AASLD radiological diagnosis the mean sensitivity, specificity and diagnostic accuracy in the diagnosis of HCC were, respectively (76.4%, 80%, 0.84).

Gadoxetic acid MR imaging is a reliable tool in the characterization of well-differentiated HCC from dysplastic and regenerative nodules.

Characterization of small nodules in cirrhotic liver is still of challenge. Basically overlap between dysplatic nodules and hypovascular HCCs may be the most common cause of misinterpretation.

Di Martino, M, Anzidei, M, Zaccagna, F, Saba, L, Catalano, C, Gadoxetic-acid MR Imaging in the Characterization of the "Grey Zone " of the Hepatocarcinogenesis.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14014190.html