动态增强MRA的临床研究

目的与常规ＭＲＡ比较，并以手术或ＤＳＡ作为金标准，评估动态增强磁共振血管成像（ＤＣＥＭＲＡ）的图像质量和应用价值。方法４０例共１３２条体部血管同时作了常规ＭＲＡ和ＤＣＥＭＲＡ检查，前者以二维时间飞跃法（２ＤＴＯＦ）ＭＲＡ为主，后者以三维（３Ｄ）ＤＣＥＭＲＡ为主，部分病例屏气扫描（２０～３０秒），快速注射ＧｄＤＴＰＡ２０ｍｌ（０．１５～０．２ｍｍｏｌ／ｋｇ），造影剂注射速度和扫描时间依据靶血管的性质、部位、范围而定。结果４０例中３５例发现有血管病变，与手术或其他影像学方法检查结果一致。３０例主动脉弓及弓上分支、腹主动脉、腔静脉及门静脉的显示满意率，２ＤＴＯＦＭＲＡ为４０％，ＤＣＥＭＲＡ为９６％，颈动脉及下肢血管则分别为９０％、７０％。利用配对计数资料χ２检验，前者两种方法有显著性差异（χ２＝１６．６５，Ｐ＜０．００１），后者无显著性差异（精确卡方检验：χ２＝０．５８，Ｐ＞０．０５）。结论ＤＣＥＭＲＡ为新的磁共振血管成像技术，克服了常规ＭＲＡ的许多缺点，尤其对胸腹部血管，两种方法血管显示满意率有极显著性差异。屏气薄层３ＤＤＣＥＭＲＡ技术，几乎达到与ＤＳＡ相仿的结果，其临床应用潜能极大。

Clinical study of contrast enhanced MRA

Purpose To evaluate the image quality and clinical efficacy of dynamic contrast enhanced MRA(DCE MRA) as compared with conventional MRA, taking operation or DSA as gold standard. Methods Conventional MRA and DCE MRA were performed in 40 persons with 132 different body vessels, the former was done mostly with 2D TOF MRA,while the latter was mostly done with 3D DCE MRA, and in some cases with breath hold acquisition(20 - 35s). 20 ml(0.15 - 0.20 mmol/kg) Gd DTPA was injected rapidly by hand. The injection rate and acquisition time were determined on the basis of location and features of the target vessels. Results 35 of 40 cases had various vascular diseases which were detected by MRA and agreed with the operative findings or other imaging modalites. The rate of satisfactory vessel visualization for 2D TOF MRA and DCE MRA were 40% and 96% respectively for aortic arch and its branches, abdominal aorta,vena cave and portal veins ( P < 0.001) in 30 cases,and 90% vs 70%( P >0.05) for carotid arteries and arteries of low extremities. Conclusion DCE MRA is a new technique of MRA, being able to overcome some pitfalls of conventional MRA, especially for thoracic abdominal vessels with significant difference in satisfactory vessel visualization. Breath hold and thin section 3D DCE MRA could yield images almost similar to DSA, therefore possessing great potential of clinical application.