Dual Inversion-Recovery MR Imaging Sequence for Reduced Blood Signal on Late Gadolinium-enhanced Images of Myocardial Scar

Abstract

To investigate whether a dual inversion-recovery (IR) prepulse improves scar-to-blood contrast and expert confidence and consistency at late gadolinium-enhanced magnetic resonance (MR) imaging of myocardial scar compared with the standard IR technique at 3.0 T. The study was approved by the local ethics committee, and all patients provided written informed consent. Twelve men (mean age±standard deviation, 63 years±8) with known myocardial scar underwent MR imaging 10, 20, and 30 minutes after administration of 0.2 mmol/kg gadobutrol with a standard and dual IR sequence. Contrast-to-noise ratios (CNRs) were measured by using region-of-interest analysis, and data were compared with the analysis of variance test. Two experts measured scar size and transmurality, and data were compared with the Student t test and Bland-Altman test. Experts assigned confidence scores for scar detection and transmurality, which were compared with a Wilcoxon matched-pairs signed rank test. Patient data showed improved scar-to-blood CNR for the dual IR technique compared with the standard IR technique at all time points (P<.05). For images obtained 20 minutes after contrast material administration, the dual IR sequence provided higher confidence scores for scar detection and transmurality assessment (P<.05) and resulted in more consistent assessment of scar size and transmurality between readers compared with the IR sequence (P<.05). In this preliminary patient study, the dual IR prepulse improved contrast, scar visualization, and expert confidence and reduced expert differences in transmurality and scar size assessment compared with the standard IR technique.