基于压缩感知3D-FLAIR序列与常规2D-FLAIR序列在脑白质病变成像中的对比研究

Comparative study of 3D-FLAIR sequence based on compressed sensing and the conventional2D-FLAIR sequence in white matter lesion imaging

目的对比分析基于压缩感知(compressed sensing,CS)技术的3D液体衰减反转恢复(fluid-attenuated inversion-recovery,FLAIR)序列与常规2D-FLAIR序列对脑白质病变的成像质量。材料与方法前瞻性纳入首都医科大学附属北京天坛医院40例同时行头部CS 3D-FLAIR序列和2D-FLAIR序列扫描的脑白质病患者。客观分析图像的信噪比(signal-to-noise ratio,SNR)和对比噪声比(contrast noise ratio,CNR),并由2名经验丰富的诊断医师对图像整体质量和脑白质病灶个数进行评估。利用Wilcoxon秩和检验进行统计分析。结果CS技术可以将3D-FLAIR序列的采集时间缩短到与2D-FLAIR序列相当。CS3D-FLAIR序列和2D-FLAIR序列图像的SNR和CNR差异无统计学意义(Z=-1.18,P=0.24;Z=-1.92,P=0.14)。CS 3D-FLAIR序列的图像整体质量评分和显示脑白质病灶个数显著优于2D-FLAIR序列(Z=-3.99,P<0.001;Z=-3.75,P=0.006)。CS 3D-FLAIR序列对第四脑室层面的搏动伪影具有抑制作用。结论扫描时长相当的情况下,CS 3D-FLAIR序列图像整体质量好,可抑制搏动伪影,比2D-FLAIR序列更利于脑白质病变的检出,建议临床推广应用。

Objective:To compare the imaging quality of 3D-FLAIR sequence based on compressed sensing(CS)with the conventional2D-FLAIR sequence in detection of brain white matter lesions.Materials and Methods:Forty patients with white matter lesions who underwent both CS 3D-FLAIR and 2D-FLAIR were analyzed.The signal-to-noise ratio(SNR)and contrast noise ratio(CNR)of the images were calculated.The overall image quality and number of the white matter lesions were evaluated by two experienced radiologists.Statistical analysis was performed by Wilcoxon assay.Results:The acquisition time of 3D-FLAIR sequence by using CS technique could be shorted to be equal to that of 2D-FLAIR sequence.No significant differences were observed for the SNR and CNR between the CS 3D-FLAIR and 2D-FLAIR sequences(Z=-1.18,P=0.24;Z=-1.92,P=0.14).The overall image quality for CS 3D-FLAIR sequence were better than the 2D-FLAIR sequence(Z=-3.99,P<0.001),and more white matter lesions were detected from the CS3D-FLAIR sequence than those from the 2D-FLAIR sequence(Z=-3.75,P=0.006).The pulsatile artifactsin the fourth-ventricle layer on the 2D-FLAIR images were suppressed on the CS 3D-FLAIR images.Conclusions:In the case of the same acquisition time,the advantages of the CS 3D-FLAIR,including better overall image quality and suppressed pulsation artifacts,make it more attractive in the detection of white matter lesions than the 2D-FLAIR,which is recommended for clinical application.