【摘要】 目的 定性和定量评估水脂分离液体衰减反转恢复（Dixon-FLAIR）序列与频率选择脂肪抑制液体衰减反转恢复（FS-FLAIR）序列在金属义齿患者颅脑MRI中的图像质量、脂肪抑制和伪影情况。方法 回顾性研究分析46例带有固定金属义齿并在3.0 T MRI设备上行Dixon-FLAIR和FS-FLAIR序列扫描的患者。两名放射科医生采用5分法定性评估整体图像质量、不同解剖层面的脂肪抑制效果及信号失真情况。另外一名放射科医生定量测量和计算两种序列的图像信噪比（SNR）、对比噪声比（CNR）及水抑制不均匀的层数。使用配对t检验进行统计，一致性评估通过Kappa系数进行分析。结果Dixon-FLAIR在所有解剖层面均表现出更优的整体图像质量（P<0.001）、更均匀的脂肪抑制效果（P<0.001）和更小的信号失真（P<0.001），一致性分析为良好至优秀（Kappa>0.6）。Dixon-FLAIR水抑制不均匀的层数明显少于FS-FLAIR序列，但SNR(P<0.001)和CNR(P<0.001)略低于FS-FLAIR序列。结论 在金属义齿患者中，Dixon-FLAIR序列在整体图像质量、脂肪抑制均匀性、信号失真抑制及水抑制均匀性方面显著优于FS-FLAIR序列，仅轻微损失图像SNR和灰白质CNR，是一种有前景的颅脑MRI扫描替代序列。更多还原

【Abstract】 Objective To qualitatively and quantitatively compare the image quality, fat suppression, and artifact reduction between Dixon fluid-attenuated inversion-recovery(Dixon-FLAIR) and frequency-selective fat suppression FLAIR(FS-FLAIR)sequences in brain MRI of patients with fixed metallic dental restorations. Methods The Dixon-FLAIR and FS-FLAIR images of46 patients with fixed ferromagnetic dental restorations acquired on a 3 T MRI system were retrospectively analyzed. Two radiologists independently assessed the overall image quality, fat suppression efficacy, and signal distortion by metal across four anatomical levels using a 5-point Likert scale. Inter-reader agreement was evaluated using Kappa statistics. Quantitative analysis performed by a third radiologist included measurements of signal-to-noise ratio(SNR) and contrast-to-noise ratio(CNR) between gray and white matter as well as the number of slices with nonuniform fluid suppression. Paired t-tests were used for statistical comparisons. Results Dixon-FLAIR images demonstrated significantly better overall image quality(P <0.001), more uniform fat suppression across all anatomical levels(P <0.001), and reduced signal distortion from metallic artifacts( P <0.001) compared to FS-FLAIR. Inter-reader agreement was good to excellent(κ >0.6). The number of slices with nonuniform fluid suppression was significantly lower on Dixon-FLAIR imaging(P<0.001). Dixon-FLAIR images showed slightly but significantly lower SNR(P<0.001) and CNR(P<0.001)than FS-FLAIR images. Conclusion Despite a slight decrease in SNR and CNR, the Dixon-FLAIR sequence provides superior image quality, more uniform fat suppression, reduced metal-induced signal distortion and improved fluid suppression uniformity compared to the conventional FS-FLAIR sequence. Dixon-FLAIR is a promising alternative sequence for brain MRI in patients with fixed metallic dental restorations.更多还原