多b值弥散加权成像与动脉自旋标记评估轻度认知功能障碍海马灌注的对比研究

Comparative study on evaluating hippocampus perfusion of patients with mild cognitive impairment by multiple b value diffusion weighted imaging and arterial spin labeling imaging

目的 :对比分析多b值弥散加权成像(MB-DWI)与动脉自旋标记(ASL)在评价轻度认知功能障碍(MCI)患者海马灌注异常中的临床应用价值。方法:依据诊断标准与排除标准,选择MCI患者(MCI组)和认知功能正常的老年人(NC组)各20例,进行常规MRI平扫、MRA、ASL以及MB-DWI扫描,根据ASL-CBF图测量双侧海马最大rCBF_(ASL)值,并测量相应区域MBDWI与灌注相关参数fast ADC-mono、fraction of fast ADC-mono、fast ADC-bi、fraction of fast ADC-bi值,对MCI组和NC组分别进行相应参数的组间统计学差异分析和Pearson相关性分析。结果:MCI组双侧海马rCBF_(ASL)值较NC组降低(P<0.05);MCI组双侧海马fast ADC-mono、fraction of fast ADC-mono、fraction of fast ADC-bi值与NC组的比较差异有统计学意义(P<0.05),双侧海马fast ADC-bi值较NC组减低,差异无统计学意义(P>0.05);除fast ADC-bi值外,MCI组fast ADC-mono、fraction of fast ADC-mono、fraction of fast ADC-bi值与r CBFASL的相关性具有统计学意义(P<0.05)。结论:MB-DWI和ASL在检出MCI患者海马的灌注改变方面具有一致性,可用于评估MCI患者灌注改变,有利于指导临床。

Objective： To compare and analyze the clinical application value of both the multiple b value diffusion weight-ed imaging（MB-DWI） and arterial spin labeling（ASL） imaging for evaluating changes of hippocampus perfusion of patients with mild cognitive impairment. Methods： Based on diagnostic criteria and exclusion criteria, 40 subjects（include 20 mild cognitive impairment and 20 elderly cognitively healthy） underwent routine MRI with MRA, ASL and MB-DWI. Bilateral hippocampus areas were selected as regions of interest and local cerebral blood flow （rCBFASL） were measured by using ASL. Parameters measured by MB-DWI were fast ADC-mono, fraction of fast ADC-mono, fast ADC-bi, and fraction of fast ADC-bi. t test was performed for bilateral hippocampus areas between MCI group and NC group. Pearson correlation analysis was performed for changes of relative values （fast ADC-mono, fraction of fast ADC-mono, fast ADC-bi, and fraction of fast ADC-bi） of parame-ters of MB-DWI and rCBFASL. Results： The rCBFASL of MCI group was lower than that of NC group, and the difference was significant （P〈0.05）. There were significantly differences among of fast ADC-mono, fraction of fast ADC-mono and fraction of fast ADC-bi between the MCI group and NC group（P〈0.05）. The fast ADC-bi of MCI group was lower than that of NC group, and the difference was not statistically significant（P〈0.05）. Except fast ADC-bi group, the differences between fast ADC-mono, fraction of fast ADC-mono, fraction of fast ADC-bi of bilateral hippocampus areas and rCBFASL were statistically significant （P〈0.05）. Conclusion： The results of MB-DWI and ASL for changes of hippocampus perfusion of patients with mild cognitive im-pairment are consistent, which can be used for evaluating changes of brain perfusion in mild cognitive impairment and are helpful for clinical diagnosis and treatment.