Percentage of signal intensity loss for characterisation of focal liver lesions in patients with chronic liver disease using ferucarbotran-enhanced MRI.

The purpose of this study was to determine the percentage of signal intensity loss (PSIL) threshold for the characterisation of focal liver lesions among patients with chronic liver disease. 55 nodules in 49 patients with chronic liver disease who underwent ferucarbotran-enhanced MR studies were included. Among the 49 patients, 40 had liver cirrhosis and 9 had chronic hepatitis. 8 haemangiomas, 3 focal nodular hyperplasia, 9 dysplastic nodules and 12 well, 19 moderately and 4 poorly differentiated hepatocellular carcinomas (HCCs) were revealed. The PSIL, signal-to-noise ratio and contrast-to-noise ratio of each lesion type were calculated. The diagnostic performance of PSIL on ferucarbotran-enhanced T(2) weighted images (PSIL(T2WI)) and T(2) weighted fat-suppression images (PSIL(FS-T2WI)) that characterised hepatic tumours was compared with receiver operating characteristic (ROC) analysis. Using ROC analysis, the diagnostic performance of PSIL(FS-T2WI) was superior to that of PSIL(T2WI) (p = 0.01). The mean PSIL(FS-T2WI) of the benign lesions was significantly higher than that of HCC (p<0.001), and the mean PSIL(FS-T2WI) of well-differentiated HCC was significantly higher than that of moderately/poorly differentiated HCCs (p = 0.001). With a PSIL(FS-T2WI) threshold of 40% in lesions characterising ferucarbotran-enhanced FS-T2WI, the sensitivity, specificity, accuracy, positive predictive value and negative predictive value were 88.6%, 95%, 90.9%, 96.9% and 82.6%, respectively. In conclusion, with ferucarbotran-enhanced FS-T2WI, a PSIL(FS-T2WI) threshold of 40% for characterising focal liver nodules among patients with chronic liver disease is recommended. It is useful for distinguishing HCC from benign nodules.