In vivo cardiac DTI on a widely available 3T clinical scanner: an optimized M2 approach

Christopher T Nguyen,Yibin Xie,Debiao Li,Peter Speier,Zhaoyang Fan,Jianing Pang,Jon Kobashigawa,Xiaoming Bi

doi:10.1186/1532-429x-18-s1-o18

Abstract

Background Currently, there are only two main methods to perform diffusion tensor CMR (DT-CMR) that either rely on the subject exhibiting stable, periodic RR cycle (stimulated echo [1]) or utilize specialized research scanners that have ultra-high gradient strengths (spin-echo [2]). Recent work has demonstrated that gradient moment nulling (GMN) of the second order is capable of yielding robust diffusion weighted images (DWI) [3]. To extend this work, we present a novel DT-CMR sequence prototype that utilizes a M2 GMN gradient scheme that is robust to imperfect B1 refocusing at high main fields (≥3T). We compare this with no GMN compensation (M0) and first order GMN compensation (M1). Patients with advanced heart failure (HF) were also scanned to test its ability in a clinical setting.

Highlights

There are only two main methods to perform diffusion tensor CMR (DT-CMR) that either rely on the subject exhibiting stable, periodic RR cycle or utilize specialized research scanners that have ultra-high gradient strengths
All subjects were scanned on a 3T Siemens (MAGNETOM Verio, Siemens Healthcare GmbH, Erlangen) with the following protocol: standard morphological localizers and 3 DTI scans (b30 + 6 directions b = 300 s/mm2, free breathing prospective navigator gating, bSSFP readout, 2.7 × 2.7 × 8 mm3, flip angle = 90°, single-shot + MoCo) utilizing M0 (TEprep = 35 ms), M1 (TEprep = 46 ms), and M2 (TEprep = 67 ms)
DTI reconstruction utilized custom software developed in Python using the DIPY library [6] to generate mean diffusivity (MD), fractional anisotropy (FA), and helix angle (HA) maps

Summary

Introduction

There are only two main methods to perform diffusion tensor CMR (DT-CMR) that either rely on the subject exhibiting stable, periodic RR cycle (stimulated echo [1]) or utilize specialized research scanners that have ultra-high gradient strengths (spin-echo [2]). Recent work has demonstrated that gradient moment nulling (GMN) of the second order is capable of yielding robust diffusion weighted images (DWI) [3]. We present a novel DT-CMR sequence prototype that utilizes a M2 GMN gradient scheme that is robust to imperfect B1 refocusing at high main fields (≥3T). We compare this with no GMN compensation (M0) and first order GMN compensation (M1). Patients with advanced heart failure (HF) were scanned to test its ability in a clinical setting

Methods

Results

Conclusion