羟基磷灰石眶内植入物的血管化程度:超声造影与增强核磁共振成像评价比较

Vascularization of hydroxyapatite orbital implants: Comparison between ultrasonic contrast and enhanced MRI

背景：羟基磷灰石义眼台眶内植入后，对其血管化程度进行检测尤为重要。目前评价羟基磷灰石眶内植入后血管化的方法都有一定的局限性，超声造影是近年来发展起来的超声新技术，对血流检测具有很高的精确性。目的：探讨超声造影评价多孔羟基磷灰石血管化程度的可行性，并与增强MRI对照。设计、时间及地点：同一条件下两种检测方式的对比观察。于2008-01/2009-01在江阴市人民医院眼科和超声科完成。对象：10例眼球摘除＋羟基磷灰石义眼座植入患者，男8例，女2例，年龄24~61岁，平均（45.0±10.2）岁。手术方式均采用带蒂巩膜瓣前部交叉包裹多孔羟基磷灰石植入式。方法：超声造影检查采用PHILIPS IU22彩色多普勒超声仪，造影剂为SonoVue，剂量为59 mg，干粉剂，主要成分为六氟化硫，用生理盐水配制成六氟化硫微泡悬浮液，每次抽出2.4 mL经肘部浅静脉以团注入。同时行对照MRI增强扫描检查，MRI检查采用Siemens Magnetom Avanto 1.5T超导型磁共振扫描，标准头部线圈。横轴位，层厚2.0~3.0 mm，无间隔，FOV160 mm×180 mm，采集矩阵256×256：SE序列T1WI（TR 500 ms，TE12 ms）平扫及增强检查，对比剂为钆喷酸葡胺注射液。主要观察指标：观察植入后不同时期两种造影方式显示的羟基磷灰石义眼座血管化的特征及程度。结果：超声造影很好的显示出了羟基磷灰石眶内植入后早期球体前部分的动态增强图像，并显示出血管分布情况，分布密度，植入后期（3~6个月）则对增强显像不明显；增强MRI对羟基磷灰石眶内植入后血管化结果显像明显。结论：超声造影应用于羟基磷灰石眶内植入后早期血管化评价作用显著，植入后期不如增强MRI敏感。

BACKGROUND： It is very important to evaluate vascularization of postoperative hydroxyapatite （HA） orbital implants in human eyes. Recently, methods for evaluating vascularization of HA orbital implants are limited; however, ultrasonic contrast is a novel technique to high-precisely measure blood flow. OBJECTIVE： To investigate the feasibility of ultrasonic contrast to evaluate the vascularization of HA orbital implants, and to compare with enhanced MRI. DESIGN, TIME AND SETTING： The comparative observation was performed at Departments of Ophthalmology and Ultrasound, Jiangyin People’s Hospital between January 2008 and January 2009. PARTICIPANTS： Ten patients including 8 males and 2 females were treated with eye ball extirpation and HA orbital implants. The patients were aged 24-61 years, with the mean age of （45.0±10.2） years. HA orbital implants were crossly coated using anterior part of pedicle scleral flap. METHODS： PHILIPS IU22 color Doppler ultrasound was used in this study, and SonoVue （59 mg） was the major contrast medium. Sulphur hexafluoride was dissolved in saline to make suspension. A 2.4-mL suspension was injected through peripheral vein of elbow. Enhanced MRI was additionally used in this study： Siemens Magnetom Avanto 1.5T, standard head coil, horizontal axis, 2.0-3.0 mm thickness, no interval, FOV 160 mm×180 mm, 256×256 matrix, and SE sequence T1WI （TR 500 ms, TE 12 ms）. Dimeglumine gadopentetate injection was used as a contrast medium. MAIN OUTCOME MEASURES： Vascularization characteristics and degrees between ultrasonic contrast and enhanced MRI at different time points after implantation. RESULTS： Ultrasonic contrast showed a well dynamic contrast-enhanced image of the anterior part of HA in early stage of post-operation, and showed distributing instance and density of blood vessel. Later stage of post-operation （about 3-6 months）, contrast-enhanced image was unconspicuous. The enhanced MRI showed a clear vascularization of HA orbital implants at the stage of post-operation. CONCLUSION： Ultrasonic contrast is a effective investigative way to evaluate vascularization of HA orbital implants in early stage of implantation, and it is limited at the later stage of post-operation than enhanced MRI.