Background: Quantitative susceptibility mapping (QSM) technique had been used to
measure the magnetic susceptibility of brain tissue in clinical practice. However, QSM presented
echo-time (TE) dependence, and an appropriate number of echo-times (nTEs) for QSM became
more important to obtain the reliable susceptibility value.
Objective: The aim of the study was to explore the optimal nTEs for quantitative susceptibility
mapping (QSM) measurements of basal ganglia nuclei in the healthy brain.
Methods: 3D multi-echo enhanced gradient recalled echo T2 star weighted angiography (ESWAN)
sequence was acquired on a 3.0T MR scanner for QSM analysis. Regions of interests
(ROIs) were drawn along the margin of the head of the caudate nucleus (HCN), putamen (Pu) and
globus pallidus (GP). The mean susceptibility value and standard deviation of the ROIs were derived
from the pixels within each region.
Results: CV analysis demonstrated that TE6, TE8 and TE14 ESWAN sequences presented consistent
lower CV value (< 1) for QSM measure of HCN, Pu and GP. ANOVA identified that susceptibility
value showed no significant difference between TE6 and TE8 in HCN, Pu and GP (P >
0.05). ICC analysis demonstrated that the susceptibility value of TE6-TE8 had the highest ICC
value as compared with TE6-TE14 and TE8-TE14 in HCN, Pu and GP. Combined with the timeefficiency
of MRI scanning, TE6 sequence could not only provide the reliable QSM measurement
but also short imaging time.
Conclusion: The current study identified that the optimal nTEs of ESWAN were 6 TEs (2.9ms ~
80.9ms) for QSM measurement of basal ganglia nuclei in the healthy brain.