Myocardial T1 mapping for patients with implanted cardiac devices using wideband inversion recovery spoiled gradient echo readout

Abstract

Purpose: To develop and validate a technique for myocardial T1 mapping in patients with implantable cardioverter defibrillators (ICDs). Methods: A MOLLI-based pulse sequence, named Wideband-FLASH-MOLLI, was developed by incorporating a fast low angle shot (FLASH) readout and a wideband inversion pulse. The performance of Wideband-FLASH-MOLLI was evaluated using phantom studies and validated in eight healthy volunteers and ten patients with ICDs at 1.5 Tesla. Comparisons were made between Wideband-FLASH-MOLLI, FLASH-MOLLI, and bSSFP-MOLLI sequences. Results: In phantom studies, the maximum T1 estimation errors using Wideband-FLASH-MOLLI with and without an ICD were less than 3% for T1 range from 212 to 1673 ms. In all healthy volunteers, there was no significant native myocardial T1 estimation difference using Wideband-FLASH-MOLLI before and after the external attachment of an ICD to the body coil (1178 ± 27 ms versus 1174 ± 33 ms; P = 0.41). Due to the presence of an ICD, the magnitude images acquired using bSSFP-MOLLI and FLASH-MOLLI showed severe artifacts within the myocardium. In contrast, no or negligible device-induced artifacts were noted within the myocardial regions of the healthy volunteers or the patients with ICDs when using Wideband-FLASH-MOLLI. Conclusion: This study demonstrates the feasibility of using Wideband-FLASH-MOLLI to mitigate image artifacts and to produce accurate myocardial T1 maps in patients with ICDs. Magn Reson Med 77:1495–1504, 2017. © 2016 International Society for Magnetic Resonance in Medicine.