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-Q1R) 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.%目的 为缩短扫描时间,在颈动脉高分辨磁共振对比增强中使用小视野四翻转恢复成像技术(SF-QIR),并评价其成像质量.方法 24例颈动脉斑块患者在同一台3.0T磁共振仪上进行颈动脉高分辨SF-QIR和常规矩形相位编码四翻转恢复(SrF-QIR)增强扫描.两种扫描序列间,除相位编码数量及射频脉冲激励方式不同外,其他扫描参数均一致.由3名独立的评价人对两种序列图像分别进行定性及定量评价.定性评价指标为颈动脉外部管壁轮廓、纤维帽及富脂质坏死核轮廓、诊断信心.定量评价指标为最大狭窄程度、管壁面积、富脂质坏死核面积、信噪比、对比噪声比.结果 相对于SrF-QIR,使用正交射频脉冲技术的SF-QIR缩短近一半的扫描时间.除了信噪比与对比噪声比外,两种序列图像间各种定性及定量评价指标均无统计学差异(P＞0.05).相对于SrF-QIR,SF-QIR损伤了37.7％的信噪比(P＜0.001).结论 颈动脉高分辨小视野QIR增强扫描技术可以有效评价颈动脉斑块形态学特征,并且能够明显缩短扫描时间及减少运动伪影.
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