高分辨率扩散加权成像与常规扩散加权成像在颅脑MRI中的比较研究

目的:评价高分辨率扩散加权成像(readout segmentation of long variable echo-trains diffusion weighted imaging,RESOLVE-DWI)颅脑MRI扫描的图像质量及其对脑组织表观扩散系数(apparent diffusion coefficient,ADC)值测量的影响,并与常规颅脑扩散加权成像(DWI)进行比较。方法:采用Siemens MAGNETOM Aera 1.5T超导MRI扫描仪,分别采集43例因头痛、头晕接受头颅MRI检查者的头颅RESOLVE-DWI和常规DWI图像,对图像质量进行主观评价和客观评价,主观评价共分为5级,客观评价为测量脑组织的信噪比及ADC值,比较2组结果。结果:对于43例受检者,RESOLVE-DWI组图像质量主观评分明显优于常规DWI组,差异有统计学意义(P<0.01);RESOLVEDWI组脑实质的平均信噪比值明显高于常规DWI组,差异有统计学意义(P0.05)。结论:RESOLVE技术应用于扩散加权成像序列能改善图像质量,提高信噪比,对脑白质ADC值的测量没有影响,可常规用于头颅扫描。

Comparative study of RESOLVE DWI and conventional DWI in brain MRI

Objective： To evaluate the quality of brain MRI with RESOLVE（readout segmentation of long variable echo-trains） DWI（ diffusion weighted imaging） and its effect on apparent diffusion coefficient（ADC） value as compared with conventional DWI. Methods： MR scanning with RESOLVE DWI and conventional DWI were performed on Siemens MAGNETOM Aera 1.5 T superconducting MRI scanner in 43 subjects with headache or dizziness. The image quality was assessed by subjective and objective evaluation methods. Five-level image quality was used in subjective evaluation. The signal-to-noise ratio（SNR） and ADC value of brain tissue were measured objectively. Comparative statistical analysis was performed for comparing the RESOLVE DWI and conventional DWI. Results： Of the 43 cases, the image quality score of RESOLVE DWI surpassed conventional DWI in subjective evaluation. The image quality differed significantly between the two groups（P〈0.01）. Average SNR of white matter in RESOLVE DWI was higher than that of conventional DWI（P〈0.01）.The ADC value of white matter was not significantly different between the two groups（P〉0.05）. Conclusions： Application of RESOLVE DWI could improve image quality and increase SNR. RESOLVE DWI had no influence on ADC value of cerebral white matter, and RESOLVE DWI could be used as a routine method for brain MRI.