MRI增强扫描在高强度聚焦超声治疗脾功能亢进症疗效评估中的价值

目的探讨MRI增强扫描在脾功能亢进症高强度聚焦超声（HIFU）治疗后疗效评估中的价值。方法回顾性分析15例脾
功能亢进症患者HIFU治疗前后的MRI平扫和增强图像，观察病灶HIFU治疗前后的信号变化和强化特点。结果HIFU治疗
后脾脏靶区在T1WI上无特异性，高、等、低信号区都可代表凝固性坏死；在T2WI上，凝固性坏死表现为低信号；增强扫描示靶区
无强化，病灶范围较T1WI和T2WI广泛。结论T2WI对脾亢HIFU消融脾脏后的凝固性坏死有较高的特异性；动态增强扫描可
以敏感地反映HIFU消融靶区的血供情况及其强化特征。MRI是临床上HIFU治疗脾亢后随访监测病灶变化无创、有效的手
段，能准确反应其组织学变化。

Enhanced magnetic resonance imaging for evaluation of hypersplenism after high-intensity focused ultrasound ablation

Objective To study the value of dynamic contrast-enhanced magnetic resonance imaging(MRI) in evaluating the curative effect of high intensity focused ultrasound(HIFU) for hypersplenism.Methods A retrospective analysis of dynamic contrast enhanced MRI data was conducted in 15 patients with hypersplenism before and after HIFU treatment to observe the signal changes and enhancement features of the lesions.Results Compared with that before treatment,the signal intensity of the lesions after HIFU could be increased,reduced or remained unchanged on T1WI without specificity;on T2WI,the signal intensity of the lesions was reduced after HIFU treatment.Dynamic contrast-enhanced MRI showed larger ablation areas than those displayed by T1WI and T2WI,and no enhancement was found in the lesions.Conclusion T2WI has a greater specificity in demonstrating coagulation necrosis of hypersplenism after HIFU ablation,and dynamic contrast-enhanced MRI has a higher sensitivity in displaying the ablation area by highlighting the blood supply and enhancement characteristics of the lesions.MRI is efficient and noninvasive in follow-up evaluation of the signal intensity as well as histological changes of the treated region after HIFU.