Utility of semiquantitative parameters to differentiate benign and malignant focal hepatic lesions.

Objective: Any distinction and the usefulness of semiquantitative parameters derived from dynamic-contrast-enhanced (DCE) MRI obtained with extracellular gadolinium contrast agent in hemangiomas, hepatocellular carcinomas (HCC) and metastases of the liver was studied prospectively.

Methods: Seventy-four focal liver lesions (consisted of 34 hemangiomas, 23 HCC, and 17 metastases) of the 37 patients underwent DCE-MRI (six phases). Functional coloured maps and subsequently semiquantitative parameters were obtained using the FuncTool. Maximum and average (avg) values of mean time to enhancement (MTE), positive enhancement integral (PEI), time to peak (TP), maximum slope of increase (MSI), maximum slope of decrease (MSD) values were measured by placing the region of interest. The diagnosis of HCC and metastases were proven histopathologically and/or clinically.

Results: The mean values of the paremeters were: In hemangiomas, avgMTE: 271.2 ± 4.7; avgPEI: 840.3 ± 77.3; avgTP: 146.6 ± 13.1; avgMSI: 999.1 ± 108.4; avgMSD: 254.1 ± 30.4. In HCC, avgMTE: 246 ± 3.6; avgPEI: 424.9 ± 31.6; avgTP: 132.8 ± 9.5; avgMSI: 484.1 ± 36.5; avgMSD: 109.1 ± 13.3. In metastases, avgMTE: 248.1 ± 8.2, avgPEI: 453.9 ± 39.6; avgTP: 142.8 ± 13.9; avgMSI: 472.6 ± 50.4 and avg MSD: 200.1 ± 38.2. Both maximum and avg values of MTE, PEI, MSI, and MSD were significantly higher in hemangiomas (P<.05). The most significant difference was found in avgPEI with 82.1% sensitivity and 67.6% specificity when 570 cutoff value was considered. The values however were not significantly different among HCC and metastases (P>.05).

Conclusions: Semiquantitative DCE-MRI parameters provide useful, complementary, and quantitative information. This technique increases diagnostic value of extracellular gadolinium contrast agent to characterize focal liver lesions and may be useful for follow-up after local-regional therapies.