Diagnostic confidence of computed tomography and magnetic resonance in focal liver pathology.

The aim of this study was to evaluate and compare the diagnostic confidence of multiphase computed tomography (CT) and magnetic resonance (MR) after administration of gadolinium-ethoxybenzyl-diethylenetriamine penta-acetic acid (Gd-EOB-DTPA) in the diagnosis of malignant-benign neoplasm of the liver in operators with different levels of experience.Forty patients underwent multiphase CT and MR after administration of Gd-EOB-DTPA. All exams were evaluated by two experienced observers independently; they rated their diagnostic confidence on a five-degree scale: 1 (certainly benign), 2 (probably benign), 3 (uncertain), 4 (probably malignant) and 5 (certainly malignant). Receiver operating characteristic curve analysis and area under the curve (AUC) were carried out for each observer and their difference was tested according to the different methodologies used.In our population, there were 15 malignant neoplasms and 25 benign neoplasms. For the CT analysis, AUC was 0.792 [SE=0.088; 95\% confidence interval (CI) 0.634-0.903] and 0.701 (SE=0.099; 95\% CI 0.535-0.835) for observers 1 and 2, respectively, whereas for the MR analysis, AUC was 0.923 (SE=0.058; 95\% CI 0.793-0.983) and 0.934 (SE=0.054; 95\% CI 0.808-0.987). For both observers, a statistically significant difference was found in diagnostic confidence between the AUC of CT and MR (P<0.05).Our results indicate that, for expert and intermediate experience observers, the diagnostic confidence using MR with Gd-EOB-DTPA is statistically significantly superior to CT with a multiphase technique.