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 disodium enhanced magnetic resonance imaging in diagnosing focal liver lesions.Materials and Methods : Gadoxetic acid disodium enhanced MRI conducted in 72 patients with two sets of hepatobiliary phase images obtained at 10 minutes and 20 minutes were reviewed retrospectively. For quantitative analysis, liver-to-lesion signal difference ratio (SDR) was measured and compared between precontrast, 10-minute delay, and 20-minute delay images. SDRs were compared between 1.5-T and 3.0-T and also between cirrhotic patients and non-cirrhotic patients. 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. Conclusion : An increase in the liver-to-lesion signal difference ratio on 10- and 20-min delay images was dependent on the patients’ hepatic function but not dependent on the magnetic strength of the imaging system. There was no significant difference in sensitivity or specificity between the 10-minute and 20-minute delay images.