Endogenous assessment of late gadolinium enhancement grey zone in patients with non-ischaemic cardiomyopathy with T1ρ and native T1 mapping

Abstract

Aims This study aims to validate and compare the feasibility of T1ρ and native longitudinal relaxation time (T1) mapping in detection of myocardial fibrosis in patients with non-ischaemic cardiomyopathy, focusing on the performance of both methods in identifying late gadolinium enhancement (LGE) grey zone. Methods and results Twenty-seven hypertrophic cardiomyopathy (HCM) patients, 16 idiopathic dilated cardiomyopathy (DCM) patients, and 18 healthy controls were prospectively enrolled for native T1 and T1ρ mapping imaging and then all the patients underwent enhancement scan for LGE extent and extracellular volume (ECV) values. In LGE positive patients, the LGE areas were divided into LGE core (6 SDs above remote myocardium) and grey zone (2–6 SDs above remote myocardium) according to the signal intensity of LGE. Both HCM and DCM patients showed significantly higher native T1 values and T1ρ values than controls no matter the presence of LGE (all P < 0.01). There were significant differences in native T1 and T1ρ values among four different types of myocardia (LGE core, grey zone, remote area and control, P < 0.0001). However, the T1ρ values of grey zone were significantly higher than control (P < 0.01), while the native T1 values were not (P = 0.089). T1ρ values were significantly associated with both native T1 values (r = 0.54, P < 0.001) and ECV values (r = 0.54, P < 0.001). Conclusion T1ρ mapping is a feasible method to detect myocardial fibrosis in patients with non-ischaemic cardiomyopathy no matter the presence of LGE. Compared with native T1, T1ρ may serve as a better discriminator in the identification of LGE grey zone.

Early detection of myocardial involvement by non-contrast T1ρ mapping of cardiac magnetic resonance in type 2 diabetes mellitus

“…There was a moderate correlation between ECV and T1ρ and a mild correlation between ECV and native T1 in our study. The same findings were also reported in a previous study ( 18 ). The correlation between ECV and T1ρ suggests that the expansion of myocardial interstitial might be related to myocardial collagen deposition, but this needed to be verified by pathology.…”

Normal Values of Magnetic Resonance T1ρ Relaxation Times in the Adult Heart at 1.5 T MRI

“…In our study, we found that T 1ρ values were positively associated with T 1 values. The same results were also reported in the study of Dong et al 18 The native T 1 is affected by excessive collagen deposit (fibrosis) mainly through the interactions of water spin with surround magnetic dipole moments of neighboring molecules, whereas T 1ρ is mainly changed by chemical exchange between free water spins and collagenbounded spins. Both T 1 and T 1ρ have been demonstrated the capability for the detection of myocardial fibrosis.…”

“…Both T 1 and T 1 ρ have been demonstrated the capability for the detection of myocardial fibrosis 8,18 . Previous studies 8,18 also show the good correlation between T 1 and T 1 ρ . In addition, we also found that T 1 ρ values were positively associated with T 2 values.…”

“…Both T 1 and T 2 measurement protocols were optimized by the vendor. T 1 ρ ‐mapping was performed using an SL‐prepared steady‐state free precession sequence 18 . Typically the following parameters were used: FOV 271 × 271 mm 2 , slice thickness 10 mm, acquired pixel size 3 × 3, recon voxel size 0.85 × 0.85 mm 2 , matrix size 64 × 64, SENSE factor 2, TR 2.5 msec, TE 1.24 ms, NSA 1, scan time 10 heartbeats, flip angle 60°.…”

“…T 1ρmapping was performed using an SL-prepared steady-state free precession sequence. 18 Typically the following parameters were used: FOV 271 Â 271 mm 2 , slice thickness 10 mm, acquired pixel size 3 Â 3, recon voxel size 0.85 Â 0.85 mm 2 , matrix size 64 Â 64, SENSE factor 2, TR 2.5 msec, TE 1.24 ms, NSA 1, scan time 10 heartbeats, flip angle 60 . Each SL pulse consisted of two continuous RF pulses with opposite phases to compensate for B 1 variations, and a refocusing pulse between the spin-locking halves to compensate for B 0 errors (Fig.…”