Focal Liver Lesion Detection in Gadoxetic Acid-enhanced Liver MRI: Effects of Scan Delay, Hepatic Function, and Magnetic Field Strength

ABSTRACT

PURPOSE: To determine the effects of scan delay, hepatic function, and magnetic field strength on the performance of gadoxetic acid enhanced magnetic resonance imaging. MATERIALS AND METHODS: Gadoxetic acid enhanced MRI conducted in 72 patients with 10 minutes and 20 minutes delay were reviewed retrospectively. For quantitative analysis, liver-to-lesion signal difference ratio (SDR) was measured and compared according to scan delay time, hepatic function and magnetic field strength. For qualitative analysis, two board-certificated radiologists reviewed 10-minute delay and 20-minute delay images. The sensitivity and specificity of each reader was compared. RESULTS: The SDR of 20-minute images in non-cirrhotic patients was significantly higher (p 0.05) to 10-min delay images. In comparisons according to the magnetic strength, there was no significant difference between 1.5-T and 3.0-T systems. Comparisons of ROC curves showed no statistically significant differences in sensitivity and specificity between 10-minute and 20-minute delay images. CONCLUSION: An increase in the liver-to-lesion signal difference ratio was dependent on the patients' hepatic function but not dependent on the magnetic strength. There was no significant difference in sensitivity or specificity between the 10-minute and 20-minute delay images.