Abstract
Purpose:
To compare the image quality and diagnostic performance of 1‐ and 3‐h delayed‐phase MR images (DPIs) after gadobenate dimeglumine injection in detecting small hepatocellular carcinomas (HCCs) in cirrhotic patients.
Materials and Methods:
Relative enhancement of the liver (RE~liver~) and HCC (RE~HCC~) and liver‐to‐lesion contrast‐to‐noise ratio (CNR) of HCC were measured quantitatively on 1‐ and 3‐h DPIs in 65 patients with 88 HCCs. For qualitative analysis, two radiologists independently evaluated three image sets in 19 patients with 25 HCCs ≤2 cm and in 16 controls without HCCs: conventional liver MR without DPI (set A), adding 1‐h DPI (set B), and adding 3‐h DPI (set C), using a 5‐point scale for diagnosing small HCCs. Diagnostic performance for small HCCs was analyzed using the alternative free‐response receiver operating characteristic method.
Results:
Mean RE~liver~ (P = 0.013) and RE~HCC~ (P < 0.001) were significantly higher on 1‐h than on 3‐h DPI, whereas CNR was significantly higher on 3‐h than on 1‐h DPI (P = 0.001). Observer‐averaged figure of merit (FOM) was significantly higher for set C than for set A (0.942 versus 0.883; P = 0.013).
Conclusion:
In cirrhotic patients, 3‐h DPI provides a higher liver‐to‐lesion contrast and a better diagnostic performance for small HCCs than 1‐h DPI. J. Magn. Reson. Imaging 2011;33:889–897. © 2011 Wiley‐Liss, Inc.