MRI characterization of focal liver lesions in non-cirrhotic patients: assessment of added value of gadoxetic acid-enhanced hepatobiliary phase imaging

Abstract

Background: To evaluate the added value of the hepatobiliary (HPB) phase in gadoxetic acid-enhanced magnetic resonance imaging (MRI) in characterizing newly discovered indeterminate focal liver lesions in non-cirrhotic patients. Results: One-hundred and twenty-five non-cirrhotic patients (median age, 46 years; range, 20–85 years; 100 females) underwent gadoxetic acid-enhanced MRI, including the 20-min delayed HPB phase, for characterization of newly discovered focal liver lesions. Images were independently evaluated by two blinded, board-certified abdominal radiologists (R1 and R2) who characterized liver lesions without and with assessment of the HPB phase images in two separate readout sessions. Confidence in diagnosis was scored on a scale from 0 to 3. Inter-observer agreement was assessed using Cohen κ statistics. Change in diagnosis and confidence in diagnosis were evaluated by Wilcoxon signed rank test. There was no significant change in diagnosis before and after evaluation of the HPB phase for both readers (p = 1.0 for R1; p = 0.34 for R2). Confidence in diagnosis decreased from average 2.8 ± 0.45 to 2.6 ± 0.59 for R1 and increased from 2.6 ± 0.83 to 2.8 ± 0.46 for R2. Change in confidence was only statistically significant for R1 (p = 0.003) but not significant for R2 (p = 0.49). Inter-reader agreement in diagnosis was good without (k = 0.66) and with (k = 0.75) inclusion of the HPB phase images. Conclusions: The added information obtained from the HPB phase of gadoxetic acid-enhanced MRI does not change the diagnosis or increase confidence in diagnosis when evaluating new indeterminate focal liver lesions in non-cirrhotic patients.