延髓梗死的磁共振扩散张量成像随访研究

Longitudinal follow-up study on diffusion tensor imaging in medulla infarct

目的应用磁共振扩散张量成像(DTI)随访延髓梗死后皮质脊髓束扩散特征的变化,及其损伤程度与临床预后的关系。方法对3例延髓梗死患者,在梗死后1个月或6个月内进行3~5次DTI检查,测量各个时期梗死灶及同侧中脑大脑脚、内囊后肢部分各向异性分数的相对值(rFA),同时进行临床神经功能评分,并应用扩散张量纤维束成像(DTT)技术进行皮质脊髓束三维重建。分析rFA值的变化以及皮质脊髓束受累程度。结果 2例患者运动功能受累较轻,恢复良好,梗死区及同侧中脑大脑脚、内囊后肢rFA值轻度降低,皮质脊髓束无受压、中断表现;1例患者运动功能受损严重且恢复缓慢,梗死区及同侧中脑大脑脚、内囊后肢rFA值明显降低,皮质脊髓束大部分中断、纤维束数量减少。结论延髓梗死后皮质脊髓束损伤以及继发逆行性变性均与患者运动功能受累和恢复有关,可为预后评价提供重要依据。

Objective To explore the change of diffusion tensor characteristics and the relationship between corticospinal tract injury and motor outcome after medulla infarction using diffusion tensor imaging （DTI）. Methods We evaluated three patients with unilateral medulla infarct. The patients underment DTI three or five times during 1 month or 6 months after stroke onset. The relative fractional anisotropy （rFA） values were measured in the medulla, cerebral peduncle, and internal capsule, and neuro- functional scores were evaluated. The three-dimensional corticospinal tract was reconstructed using diffusion tensor tractography （DTI＇）. The changes of the rFA values and the relationship between corticospinal tract injury and motor outcome were studied. Results Two patients showed good motor recovery, and the rFA values in the medulla, cerebral peduncle, and internal capsule were slightly decreased. DTFs demonstrated the corticospinal tract was not compressed and interrupted. The third patient had the most obvious decrease in rFA values, with serious motor function damage. The affected corticospinal tract passed through the in- farct and was disrupted. Conclusion The corticospinal tract injury and secondary retrograde degeneration were related with the movement function involvement and recovery in medulla infarct patients, which can provide important basis for evaluation of prog- nosis.