OBJECTIVETo reduce the acquisition time of carotid high-resolution contrast-enhanced magnetic resonance imaging (CEMRI), we designed a small field-of-view (FOV) quadruple-inversion-recovery (SF-QIR) T1WI and evaluated the image quality.

METHODSTwenty-four subjects with carotid plaque were enrolled in our study. All the subjects were imaged using the same 3.0T MRI by SF-QIR and standard rectangular FOV QIR (SrF-QIR) with identical parameters except for the phase-encoding step numbers and the RF excitation methods. Three independent readers qualitatively evaluated the differences between the two sequences in regard of the carotid outer wall border delineation, fibrous cap and lipid-rich necrotic core (LR-NC) border delineation, and diagnostic confidence. The quantitative measurements included maximal stenosis, wall area, LR-NC area, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR). The inter-reader variability was assessed.

RESULTSThe application of SF-QIR combined with orthogonal radio frequency excitation resulted in nearly half of the scan time with the SrF-QIR. Both qualitative and quantitative assessment by the readers revealed no significant differences between the two sequences except for SNR and CNR (Pgt;0.05). Since the mean loss of SNR with SF-QIR was 37.7%, SrF-QIR demonstrated a superior performance in SNR (P<0.001).

CONCLUSIONThe small FOV QIR sequence is effective in high-resolution CEMRI for evaluating carotid plaques and can effectively reduce the scan time and eliminate motion artifacts.