Abstract: Objective To 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. Methods Twenty-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. Results The 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 (P>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). Conclusion The 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.