Application of the magnetic resonance angiography in elderly patients with arterial diseases of lower extremity / 中华老年医学杂志

ABSTRACT

Objective To evaluate the magnetic resonance angiography(MRA) in senile lower extremity arterial disease and to compare the diagnostic value of two dimensional time of flight(2D TOF) with three dimensional contrast enhancement(3D CE) technique. Methods Seventy patients with a mean age of 75 years underwent MRA for suspected acute or chronic lower extremity arterial disease. MRA was performed with a 1 5 T MR scanner and Gd DTPA was used by manual injection in 3D CE MRA. Among 52 patients examined with 2D TOF MRA, 18 of them underwent an additional 3D CE MRA, 32 patients took Doppler ultrasound examination, and 4 patients received emergency operation. Results In all 70 patients, 52 showed atherosclerotic stenosis disease, 17 atherosclerotic occlusive disease (4 of them were verified by emergency operation) and one patient atherosclerosis with aneurysmal dilatation. A total of 997 vessel segments were shown on MRA images and 600 of them were abnormal including 486(81%) mild to moderate stenoses, 114(19%) severe stenoses and 451 curved arterial segments. In 32 patients who underwent Doppler ultrasound, the diagnosis and its grading based on MRA was well correlated with that from Doppler ultrasound (coincidence rate was 91% and 96% respectively). A total of 764 suprapopliteal and 125 infrapopliteal arteries were depicted by 2D TOF MRA (visibility was 99% and 40% respectively). In 18 patients who received additional 3D CE MRA, totally 306 arteries were depicted on MRA (visibility 100%). Doppler ultrasound showed 40 segments with arterial calcification and 32 atherosclerotic plaques. Conclusions MRA is quite useful in detecting lower extremity arterial disease because of its noninvasion and convenience. The results derived from MRA are well correlated with that of Doppler ultrasound and clinical outcome. 3D MRA is superior to 2D TOF MRA in image quality, accuracy and time efficiency and is best for emergency case. Pitfalls of MRA such as overestimation in the severity of the disease and the long scanning time of 2D TOF must be taken into consideration .