复发缓解型多发性硬化患者脑内病灶动态对比增强MRI灌注及渗透特点

Studies of the perfusion and permeability characteristic in the brain lesions of patients with relapsing-remitting multiple sclerosis using dynamic contrast-enhanced MRI

目的探讨动态对比增强MRI（DCE—MRI）结合Patlak模型评估多发性硬化（MS）患者病灶及看似正常白质（NAWM）区的渗透和灌注特点的价值。方法回顾性分析23例复发，缓解型多发性硬化（RRMs）患者的影像检查资料，所有患者行常规MRI和DCE—MRI检查，然后应用单室Patlak模型进行数据后处理，计算MS患者脑内非强化病灶、病灶旁NAWM区、远离病灶NAWM区的容积转移常数（Ktrans）、对比剂血管内容积（vp）及灌注参数脑血流量（CBF）和脑血容量（CBV），以中位数（上四分位数，下四分位数）表示，采用Kruskal—WallisH秩和检验进行统计学分析，并绘制灌注伪彩图。结果非强化病灶区、病灶旁NAWM区与远离病灶NAWM区的Ktrans值分别为0．132（0．064，0．233）、0．111（0．060，0．233）、0．077（0．044，0．185）min-1，非强化病灶区的Ktrans值明显高于远离病灶的NAWM区（χ2=7．582，P〈0．05），病灶旁NAWM区Ktrans。值与非强化病灶区和远离病灶NAWM区Ktrans。差异均无统计学意义（P值均〉0．05）。非强化病灶区、病灶旁NAWM区与远离病灶NAWM区的CBV值分别为10．660（5．555，22．193）、9．359（4．883，16．290）、6．814（4．699，13．623）ml·100g-1，非强化病灶CBV明显高于远离病灶NAWM区，差异有统计学意义（χ2=6．394，P〈0．05）；病灶旁NAWM区与非强化病灶及远离病灶旁NAWM区的CBV差异均无统计学意义（P值均〉0．05）。3个部位间vp和CBF差异均无统计学意义（P值均〉0．05）。结论基于T1WI的DCE—MRI结合Patlak模型能定量分析MS患者病灶及NAWM区的灌注及渗透特点，准确地反映MS的血流动力学改变。

Objective To evaluate dynamic contrast-enhanced MRI （DCE-MRI） with Patlak model for depicting the perfusion and permeability characteristics of lesions and normal-appearing white matter （NAWM） regions in patients with relapsing-remitting multiple sclerosis （RRMS）. Methods Twenty-three patients with clinical confirmed RRMS were retrospectively analyzed, who had underwent conventional MRI and DCE-MRI using a 3.0 T MR scanner . The clinical characteristics and imaging data were collected. Post-processing was performed using the Patlak model. Volume transfer constant （Ktrans）, fractional plasma volume （Vp） and perfusion parameters including cerebral blood flow （CBF） and cerebral blood volume （CBV） were represented as median and interquartile range（IQR）. The four parameters of non-enhanced（NE） lesions, NAWM regions located close to NE lesions（NAWM close） and NAWM regions located far from NE lesions （NAWM far） were compared using the Kruskal-Wallis H rank sum test. Artificial color mappings were also proceeded. Results MR imaging biomarkers Ktrabs was 0.132（0.064, 0.233） min - 1 for NE lesions, 0.111 （0.060, 0.233） min-1 for NAWM close and 0.077（0.044, 0.185） min-1 for NAWM far, respectively. CBV was 10.660（5.555, 22.193） ml· 100 g-1for NE lesions, 9.359（4.883, 16.290） ml· 100 g-1 for NAWM close, 6.814 （4.699, 13.623） ml. 100 g-1 for NAWM far, respectively. Ktrans and CBV of NE lesions was significantly higher than that of NAWM far（χ2=7.582, P〈0.05; χ2=6.394, P〈0.05, respectively）. K and CBV of NAWM close showed no significant differences compared with NE lesions and NAWM far. Vp and CBF had no significant differences between NE lesions, NAWM close and NAWM far regions（P〉0.05）. Conclusion DCE-MRI with Patlak model can measure perfusion and permeability characteristics and hemodynamic abnormalities of NE lesions and NAWM regions in patients with multiple sclerosis.