Comparison of GRE versus SSFP-based cardiac T1-mapping in device patients.
Academic Article
Overview
abstract
BackgroundCardiac magnetic resonance (CMR) is challenging in patients implanted with metallic devices, such as pacemakers or defibrillators, given metallic susceptibility artifacts. The technique of T1-mapping investigates interstitial fibrosis. The most used method for myocardial T1-mapping is the modified Look-Locker Inversion recovery sequence (MOLLI) using balanced steady-state free precession (SSFP). However, SSFP is susceptible to off-resonance artifacts, leading to errors. Gradient echo (GRE) sequences are less prone to these artifacts.PurposeTo investigate whether T1-mapping using GRE was comparable to SSFP in this population.Material and MethodsPre/post-contrast T1-mapping was performed on 16 devices utilizing MOLLI with SSFP and GRE strategies at 1.5 T, as well as 10 non-device controls. The difference in mean T1 time by SSFP versus GRE (both pre- and post-contrast for each slice) for device patients was analyzed.ResultsNative T1 for the device cohort was 1053 ± 94 ms for SSFP and 969 ± 83 ms for GRE. GRE T1 measurements were shorter than SSFP measurements (difference over all slices for SSFP vs. GRE pre-/post-contrast were 74 ms and 27 ms). Mean λ for GRE (devices) was 0.520 ± 0.194 (p = 0.30). λ for SSFP (devices) was 0.536 ± 0.124 (P = 0.08). There was no difference in λ between SSFP versus GRE in device patients (P = 0.91). The percentage of segments identified as artifact on T1 maps for device patients was 24% and 45% for GRE and SSFP, respectively.ConclusionCompared to SSFP, T1 values using GRE were consistently shorter, while λ values remained equivalent. There was less visual artifact on GRE images, suggesting advantageous utility over SSFP in patients with cardiac devices.
