3.0T高分辨磁共振研究大脑中动脉粥样硬化性狭窄重构模式

Remodeling Pattern of Atherosclerotic Middle Cerebral Artery Stenosis on 3.0T High-Resolution Magnetic Resonance Imaging

目的应用3.0T高分辨磁共振成像(high resolution magnetic resonance imaging,HRMRI)探讨症状性大脑中动脉(middle cerebral artery,MCA)粥样硬化性狭窄的重构模式。方法 2009年11月～2011年5月连续入组经数字减影血管造影证实的症状性MCA M1段动脉粥样硬化性狭窄(50%～99%)患者87例,使用3.0T磁共振扫描仪对狭窄段进行HRMRI检查,测量并计算重构指数(remodeling index,RI)(最窄处血管面积/参考血管面积)。RJ≤0.95为阴性重构,RI≥1.05为阳性重构,R1在0.95～1.05之间为无重构。比较阴性重构和阳性重构病变的管壁特点。结果本研究70例惠者纳入最终分析,其中阴性重构29例,无重构6例,阳性重构35例。阴性重构病变的管壁面积(11.5±3.0)mm^2及斑块负荷(9.5±17.3)%均小于阳性重构病变的管壁面积(16.6±4.5)mm^2及斑块负荷(42.3±11.0)%,差异具有显著性(P均<0.001)。结论 HRMRI有助于评估病变的RI,在MCA动脉粥样硬化性狭窄病变中,阴性重构同样常见,且与阳性重构病变相比,其管壁面积及斑块负荷更小。

Objective To investigate the remodeling pattern of symptomatic atherosclerotic middle cerebral artery（MCA） stenosis with 3.0T high-resolution magnetic resonance imaging（HRMRI）. Methods Eighty-seven consecutive patients with symptomatic atherosclerotic stenoses at M1 segment of MCA on digital subtraction angiography（DSA）（50%-99%） were enrolled from November 2009 to May 2011. HRMRI was performed on the target segment by using a 3.0T MR scanner. Remodeling index（RI） was calculated as vessel area at maximal lumen narrowing（MLN）/ reference vessel area. RI ~〈 0.95 was defined as negative remodeling（NR）, RI ~〉 1.05 as positive remodeling（PR）, and 0.95 〉 RI 〈 1.05 as intermediate remodeling（IR）. Wall characteristics were compared between the NR and PR group. Results Seventy patients were included in the final analysis, and NR was found in 29（41.4%） patients, IR in 6（8.6%） patients, and PR in 35（50.0%） patients. At MLN sites, compared with lesions with PR, lesions with NR had a less wall area（[ll.5＋3.0]mm2 vs [16.6＋4.5]mm2, P〈0.001）, and percent plaque burden（[9.5＋l 7.31% vs [42.34-11.01%, P〈0.001）. Conclusion HRMRI can help assess the remodeling pattem of MCA stenosis. In patients with MCA atherosclerotic stenosis, NR lesions are also frequently observed and have a less wall area and plaque burden than PR lesions.