Diagnostic performance of T1- and T2-mapping in HTx patients to identify acute cellular rejection (ACR) in comparison to conventional CMR techniques and endomyocardial biopsy (EMB) as the standard of reference

Abstract

Methods Thirty-five CMRs were performed (mean age 53±11 years, 24male) using a 1.5T scanner (Achieva, Philips medical systems, Best, The Netherlands) compared to EMB. The CMR-protocol included conventional sequences to assess myocardial edema ratio (ER), a T1-weighted spinecho sequence for global relative enhancement (gRE) and inversion recovery sequences to visualize late gadolinium enhancement (LE). Histological grading according to the International Society for Heart and Lung Transplantation (ISHLT) from 1990, in which grade ≥1B was considered as a clinically relevant ACR, which has to be treated. T1-quantification was performed using the modified Look-Locker inversion-recovery (MOLLI) sequence before and 15 minutes after administration of 0.1 mmol/kg body weight of Gadobutrol (Gadovist, Bayer HealthCare, Berlin, Germany). T2-quantification was performed using a freebreathing, navigator-gated multi-echo-sequence. Global myocardial T1 preand post-contrast, T2 and ECV maps were calculated with a dedicated Software (cvi42).