弥散峰度成像对急性脑梗死半暗带诊断价值的临床研究

目的探讨磁共振弥散峰度成像技术(diffusion kurtosis imaging,DKI)对急性脑梗死半暗带诊断、病情严重度判断、疗效观察的临床价值。材料与方法急性脑梗死43例,分为三组:超急性期(13例)、急性期(14例)、亚急性期(16例),行头颅MRI、DTI、DKI、T2-FLAIR扫描,测量MK、MD图的病灶面积及MK、MD值,以病灶对侧正常镜像区作为对照,经对比及分析后,进行统计学分析。结果 (1)三组MK图异常信号区表现为不均匀、边缘清晰的高信号,MD图异常信号区则相反。(2)三组病灶区MK值升高、MD值下降与镜像区比较有显著性差异。(3)三组MK图病灶面积明显小于MD图。二者重叠部分为匹配区,非重叠部分为不匹配区。不匹配区出现率:超急性期组86.4%,急性期组92.8%,亚急性期组75%。(4)三组病灶区?MK明显大于?MD。(5)三组病灶侧匹配区的MK、MD值和?MK、?MD变化明显大于不匹配区。(6)三组MK、MD面积和MK、MD值与脑梗死病情严重程度(NIHSS评分)呈显著正相关和正相关。(7)14例复查T2-FLAIR病灶:(1)同首次MK图比较:10例基本一致,提示疗效佳,4例明显变大,提示疗效差;(2)与首次MD图比较:10例变小,提示疗效佳,2例基本一致,提示稳定,2例明显变大,提示效果差。结论 DKI可显示急性脑梗死坏死区和缺血区,对半暗带有诊断价值;能评估病情严重程度;动态监测可评价治疗效果。

Clinical study of magnetic resonance diffusion kurtosis imaging technology on half dark with acute cerebral infarction diagnosis value

Objective: The purpose of this study was to analyze the clinical value of diffusional kurtosis imaging on diagnosis, prognosis and observation of curative effect of ischemic penumbra. Materials and Methods: Forty-three patients were divided into superacute stage group (n=13), acute stage group (n=14) and subacute group (n=16). All the patients were examined with conventional MRI, DTI, DKI and T2-FLAIR, measured the area of abnormal signal of MK and MD maps. MK values and MD values of the corresponding parts of the mirror side were used as controls. These data were used for statistical analysis. Results: (1) The MD maps of our three groups in the lesion side showed relatively homogeneous low signal with fuzzy edge, in comparison, the MK maps showed heterogeneous high signal with clear edge. (2) In the lesion, the increase in the MK value, decrease in the MD value was different from that of the reference side (P<0.01). (3) The lesion area (mm2)in the MK map was obviously smaller than that in the MD map, with their difference being the mismatch area. The mismatch occurrence rate were 86.4%, 92.8%, 75.0% respectively in superacute, acute and subacute group. (4) ?MK was apparently greater than ?MD in the lesion. (5) MK, MD, ?MK,?MD value in the match area varied a lot more than that of the mismatch area. (6) The lesion area in the MK and MD map and the MK and MD value positively correlated to the severity of ischemia evaluated by NHISS. (7) Fourteen cases were followed up with T2-FLAIR: ① Compared with the primitive MK map: ten cases showed almost the same lesion area, indicating good curative effect, 4 cases showed severely enlarged lesion area, indicating poor clinical outcome. ② Compared with the primitive MD map:ten cases showed smaller lesion area, indicating good curative effect, 2 cases showed the same lesion area, indicating stable clinical state, 2 cases showed significantly enlarged lesion area, indicating poor clinical outcome. Conclusions: DKI was able to differentiate infarct and ischemic area separately in ischemia, and it played an important role in detecting penumbra. Moreover, it could be used to evaluate the severity of ischemia and the curative effect if the patients were followed up with this technique in the long term.