| With the development of the society, the population of theadvanced age increased. The morbidity of the advanced age relateddiseases increased greatly. Among them the disease of the arterystenosis, like the arteriosclerosis, the diabetes related blood vasculitisand the artery embolism are very common. Accordingly this willrequire much advanced diagnosis methods. As a very importantnon-intervene diagnosis method for the vascular disease, the usage ofCE MRA in the diagnosis of the artery stenotic disease must becomemuch broader.We retrospectively analyzed the pelvic and lower limbs arterystenosis in the 3rd hospital of Jilin university from January 2001 toJanuary 2005 and explored the accuracy, the reliability and the clinicvalue of the CE MRA in the evaluation of the outflow in the arterystenosis disease.All the patients'diagnosis were convicted by the operation andall the patients had Contrast enhanced MR angiography done beforethe operation. The examinations were performed on a 1.5 T GE Signacv/i MR scanner, in combination with a receive-only single coil. Thepatient was resupine prone position. Three dimensional spoiled GREwas used . Sequence parameters were TR/TE/FLIP ANGLE6.7~6.8/1.1/45°,NEX 0.5, matrix 128×256。In front 25mlinjection rate was 3ml/s, and in last 20ml it was 0.6-0.8ml/s. It isavailable of the dual injection rate to detect calf vessel, in reason thatcan decrease the repetition time ,reduce the effect of contrastmedium dispersed and retain thickness of contrast medium. Thesequence of SPGR can enhance T1 contrast degree and effect ofcontrast medium (gadolinium) .It is in order to decrease losed-phaseerror signal and decline of T2* signal intensity that To choice the shortecho time. Use of half-foureier acquisition can decrease scan time ,andnot decline space intensity ratio in three dimensional contrastenhanced MRA. The pre-contrast mask sequence was then subtractedfrom the post-contrast sequence acquired. Maximum intensityprojections were calculated from the subtracted data sets. Technique ofsubtracted angiography can decline signal of background, increasesignal noise rate, decrease used quantity of used contrast medium andremove useless signal. In all the 77 patients, there were 78 arteries examined. We found that 55 of 59 stenotic and occlusive arteries were indicated to have outflow by the CE MRA examination before the operation andall were indicated by the operation. 1 of 19 occlusive runoffvessels by the operation have outflow vessels. In our study, thesensitivity ,the speciality and the diagnostic accuracy in assessingrunoff vessels of the artery stenotic diseases is respectively 93.2%,94.7%, 93.6%. What James et al. and Gong Lianggeng et al. foundwas respectively 94%, 97%, 94%. In our study, the sensitivity andthe diagnostic abreast ratio was very similar with the researchesdone by James and Gong Lianggeng, the speciality is little lowerthan the researches of James. In 4 stenotic arteries, which weredemonstrated runoff vessels by the operation but not indicated bythe CE MRA before operation, only 1 segment was indicatedbypass vessels by CE MRA; in 19 occlusive arteries demonstratedby the operation, only 1 segment were detected bypass vessels inCE MRA , and 1 segment detected the bypass vessels in the CEMRA imaging before the operation. This demonstrates therelationship which the runoff vessels be underwent CE MRA andbypass vessels. In summary, it is demonstrated in our study: the methodsthat is assessing the runoff vessels of abdomen pelvis andlower extremity artery occlusion by CE MRA is accurate and...
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