| With the development of the living standard of the people in our country and the coming of an aging population, the morbidity rate of blood vascular system disease is also increasing. At the present time, the"golden criteria"of the diagnosis of peripheral vascular occlusion ailment is DSA, But it cannot be used popularly because of its limitation. In recent years, with the development of the technology of MRI, the 3D CE-MRA has been the main method to diagnose vascular occlusion of lower extremities. The major objective of this research is to ascertain the diagnostic value of 3D CE-MRA on vascular occlusion diseases of lower extremities.Main methods are as follows: German Siemens Avanto 1.5T magnetic resonance machine, the patients were supine and feet entering first and were examed by the advanced technology of MATRIX and three-section moving-bed. All the cases were scanned by 2D TOF-MRA and FLASH3D. The scanning parameters are as follows: field of vision 48mm×48mm, matrix 256×256, thickness 4mm, TE 9 ms, collection times 2. The scanning ranges are from renal artery level of abdominal aorta to feet. The contrast medium was Magnevist, a kind of paramagnetism constrast medium,the average concentration was 0.2mmol/ml, the dose was three times of conventional contrast enhancement (0.2ml/kg). The injectionapproach was through medial cubital vein with high pressure syringe, the injection speed was 2.5ml/s. The scan method was adopted the technology of care-bolus to observe dynamically the arriving time of the contrast medium to abdominal aorta. Because of the scanning field was from renal artery level of abdominal aorta to feet, we divided the field of vision into three sections, namely abdominal, thigh, and calf, the switch of the field of vision of the three-section was adopted the automatically moving-bed technology. Firstly, to scan the mask film before the contrast medium injection, secondly to collect the original images after the contrast medium injection and then subtracting it with the mask film. We could get three-diameter vascular images by maximum intensityprojection(MIP) of the subtracted original images, and then get the complete abdominal, pelvic and lower extremities vascular images by applying the composing software. Results: the cases were diagnosed by CE-MRA as follows: 58 cases of lower extremity atherosclerosis obliterans , in these cases, there were 40 vessels of abdominal aorta), 48 vessels of arteria iliaca, 64 vessels of arteria cruralis, 32 vessels of popliteal artery, and 44 vessels of arteria cnemis; and 12 cases of lower extremity A-V fistula, among them one case was congenital abnormality, the others were acquired; 5 cases of lower extremity acute embolism; 4 cases of vascular occlusion angeitides; and 2 case of abdominalaorta and lower extremity blood tumor; 1 case of lower extremity traumatic obliteration. Compared with the results of the operation and /or the results of DSA, 67 cases were correct. Among them there were 54 cases of lower extremity traumatic obliteration, 10 cases of arteriovenous fistula, the other were basically identical. In comparision, the accordance is 92.68%.Conclusion:1. The value of 3D CE-MRA on lower extremity vascular was definite and superior to Doppler ultrasound and CTA.2. The 3D CE-MRA was more accurate imaging method on displaying the whole lower extremity vascular clearly and the pre-operation positive and quantity diagnosis.3. The research indicates that the accordance of the results of 3D CE-MRA and the operation pathology and/or the results of DSA is 92.68%. So in the coming years, with the development of the software and hardware of MRA, the combination of 3D CE-MRA and color Doppler image will definitely replace the DSA and will become the best method to examine the lower extremity vascular disease.
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