对比分析螺旋桨与线性k空间填充方式在颅脑MRI中的应用

目的探讨螺旋桨式k空间填充方式在颅脑MRI中的应用价值。方法对同一患者同时行PROPT2WI和FRFSE T2 WI,PROP T2 FLAIR和FLAIR轴位扫描,对不能配合检查的23例患者,进行图像质量评分;对配合检查的40例脑梗死患者对比图像的信噪比（SNR）和对比噪声比（CNR）。结果不能配合检查的患者PROP T2 WI和PROP T2 FLAIR图像运动伪影显著减少,图像质量评分明显高于FRFSE T2 WI和FLAIR（P=0.000,P=0.000）。配合检查的脑梗死患者,其PROP T2 WI和PROP T2 FLAIR的SNR明显高于FRFSET2WI和FLAIR（P=0.000,P=0.002）,PROP T2 WI的CNR明显高于FRFSE T2 WI（P=0.000）,而PROP T2 FLAIR和FLAIR的CNR则没有显著性差异（P=0.150）。结论PROPELLER技术在减少运动伪影,提高图像SNR上优于线性k空间填充方式,而且并不降低病变的对比,甚至在T2WI上可以提高图像的对比度。所以在颅脑MRI中,螺旋桨式k空间填充方式可以作为常规序列。

Comparison of PROPELLER and linear k-space filling techniques in MR imaging of brain

Objective To evaluate the value of PROPELLER technique in MRI of brain. Methods PROP T2WI and FRFSE T2WI, PROP T2 FLAIR and FLAIR images were achieved in the same patient. For 23 noncooperative patients, the image quality was evaluated and graded. And for those 40 cooperative patients with cerebral infarction, the signal noise ratio (SNR) and contrast noise ratio (CNR) were compared. Results For noncooperative patients, the PROPELLER techniques reduce the motion artifact greatly and improve the grade of image quality significantly, compared with linear k-space filling techniques (P=0.000, P=0.000). For cooperative patients, the SNR of PROP T2W and PROP T2 FLAIR images is significantly higher than that of FRFSE T2W and FLAIR images (P=0.000, P=0.002). And the CNR of PROP T2WIs was significantly higher than that of FRFSE T2WIs (P=0.000). There is no significant difference in CNR between PROP T2 FLAIR and FLAIR images (P=0.150). Conclusion PROPELLER technique can greatly reduce motion artifact and elevate SNR, compared with linear k-space filling technique. Besides better image quality, the CNR is not reduced and PROP T2WI sequence even increases the CNR compared with FRFSE T2W sequence. So in MR imaging of brain, the PROPELLER technique can be incorporated in conventional sequences.