Distinguishing hemangiomas from malignant solid hepatic lesions: a comparison of heavily T2-weighted images obtained before and after administration of gadoxetic acid.

Abstract

PURPOSE: To compare the use of heavily T2-weighted images obtained before and after administration of gadoxetic acid in differentiating hemangiomas from malignant solid hepatic lesions.

MATERIALS AND METHODS: Heavily T2-weighted images (TE=150 msec) were obtained for 70 patients (42 men and 28 women) with 74 focal hepatic lesions (25 hepatocellular carcinomas [HCC], 22 metastases, and 27 hemangiomas) ≤3 cm in diameter before and after gadoxetic acid-enhanced dynamic magnetic resonance imaging (MRI). Quantitative analysis was performed using receiver operating characteristic (ROC) curves with lesion-to-liver signal intensity difference-to-noise ratio (SDNR) on precontrast and postcontrast images. Qualitative analysis was also performed by two blinded reviewers.

RESULTS: The SDNR of the solid lesions was significantly higher on the postcontrast (1.66 ± 1.18) than on the precontrast (1.38 ± 1.07) images (P=0.0012), while the SDNR of hemangiomas was comparable for pre- and postcontrast images (P=0.8164). The best SDNR cutoff values for distinguishing solid lesions from hemangiomas were ≤1.85 (Az=0.948) for precontrast and ≤2.58 (Az=0.901) for postcontrast images (P=0.057). Reader performances for distinguishing hemangiomas from solid lesions were comparable between the precontrast (Az=0.975 and 0.970 for readers 1 and 2) and postcontrast (Az=0.977 and 0.972) images (P=0.899 and 0.946).

CONCLUSION: Heavily T2-weighted images obtained after administration of gadoxetic acid have a diagnostic capability comparable to precontrast images for differentiating between small hemangiomas and malignant solid lesions of the liver.