Tomoko Hyodo MD, Presenter: Nothing to Disclose

Masahiro Okada MD, Abstract Co-Author: Nothing to Disclose

Masatoshi Hori MD, Abstract Co-Author: Nothing to Disclose

Yasuharu Imai, Abstract Co-Author: Nothing to Disclose

Masatoshi Kudo, Abstract Co-Author: Nothing to Disclose

Takamichi Murakami MD, PhD, Abstract Co-Author: Nothing to Disclose

Teruhito Mochizuki MD, Abstract Co-Author: Nothing to Disclose

Yuki Kagawa MD, Abstract Co-Author: Nothing to Disclose

Sachiyo Kogita, Abstract Co-Author: Nothing to Disclose

Seishi Kumano MD, Abstract Co-Author: Nothing to Disclose

To determine incidence and risk factors for arterial hypervascularization, assumed to be a development into hypervascular HCC, from hypovascular nodules presented with hypointensity on hepatobiliary phase of Gd-EOB-DTPA enhanced MRI (EOB-MRI) in the cirrhotic liver.

We retrospectively reviewed 160 hypovascular nodules in 68 cirrhotic patients with multiple follow-up EOB-MRI examinations. The nodules on baseline MR images were reviewed, noting 1) the size on hepatobiliary phase images of the EOB-MRI, 2) signal intensity on T2-weighted turbo spin-echo (T2W TSE) and pre- and postcontrast T1-weighted, and 3) fat-containing on in and opposed phases images. The risk factors for hypervascularization were determined from the baseline patient characteristics and MR findings using generalized Cox regression model. Additionally, the growth rate (GR) was calculated as reciprocal of tumor volume doubling time (TVDT) to perform ROC analysis to examine the relationship with hypervascularization.

Hypervascularization was confirmed in 50 (31%) of the 160 nodules during the observation interval (median, 342 days). The following factors were significantly associated with an increased risk of hypervascularization: hyperintense on T2W TSE image (HR=8.2; 95%CI: 3.5 – 19.3), previous local therapy for HCC (HR=5.3; 95%CI: 2.1-13.7), Child-Pugh B (HR=3.6; 95%CI: 1.3 – 9.9) and co-existence of hypervascular HCC (HR=2.0; 95%CI: 1.0-3.9). HBV infection was independently related to a decreased risk (HR=0.2; 95%CI: 0.05-0.6). In growth analysis, there was significant difference in mean GR between nodules with and without hypervascularization (p<0.05). Initial nodule diameter and GR were not significantly associated (Kendall's tau= -0.11; p<0.05). ROC analysis (AUC, 0.85) revealed that the cut-off GR 2.6x10-3 /day (TVDT, 391 days); Positive and negative predictive values were 84% and 71%, respectively.

The incidence of hypervascularization from hypovascular nodules presented with hypointensity on the hepatobiliary phase of EOB-MRI was 31%. Hyperintense on T2W TSE image is an independent and strong risk factor for hypervascularization. GR >2.6x10-3 /day may justify short-term follow-up or biopsy.

MRI findings including hyperintense on T2WI and larger growth rate can predict hypervascularization from hypovascular nodules in cirrhotic patients, which leads to early diagnosis and treatment of HCC

Hyodo, T, Okada, M, Hori, M, Imai, Y, Kudo, M, Murakami, T, Mochizuki, T, Kagawa, Y, Kogita, S, Kumano, S, Hypovascular Nodules on the Hepatobiliary Phase of Gd-EOB-DTPA-enhanced MRI in the Cirrhotic Liver: Baseline Patient Characteristics, MRI Findings, and Tumor Growth Kinetics for Prediction of Hypervascularization.  Radiological Society of North America 2011 Scientific Assembly and Annual Meeting, November 26 - December 2, 2011 ,Chicago IL. http://archive.rsna.org/2011/11001072.html