1.Evaluation of intracranial arteriovenous malformations before and after embolization with dynamic MR digital subtraction angiography
Shuang CHEN ; Xiaoyuan FENG ; Baleriaux DANILLE ; Metens THERRY
Chinese Journal of Radiology 1999;0(10):-
Objective To evaluate the clinical utility and accuracy of dynamic MR digital subtraction angiography(MR-DSA) in the detection of intracranial arteriovenous malformations before and after embolization. Methods A prospective blinded comparison of MR-DSA, 3D contrast-enhanced T_1-weighted MR angiography(3D-CEMRA), proton-weighted imaging and conventional digital subtraction angiography(DSA) were underwent in 22 consecutive AVMs patients before and after embolization. Two readers independently interpreted images and compared with DSA images. Results There was complete agreement between MR-DSA and DSA for classification and size of nidus before and after embolization in all cases. MR-DSA showed the modified hemodynamic features(the time of nidus, early venous enhancement delayed after carotid arteries appearance) in 17 cases, and nidus size were reduced in 13 cases (including 4 complete embolized cases) after embolization, which were 100% consistence compared with DSA. MR-DSA failed to depict 1 intranidal aneurysm and missed 1 less dilated artery and draining vein after embolization respectively, which were demonstrated clearly by 3D-CEMRA confirmed with DSA. The relatively more or less hyperintensity could be seen on proton-weighted imaging in all cases after embolization than before. Conclusion MR-DSA is a fast, efficient, and noninvasive technique to provide hemodynamic information relevant for AVMs before and after embolization. Proton imaging is sensitive in delineation of the embolized region, MR-DSA, 3D-CEMRA and proton-weighted imaging should be combined in the evaluation and follow-up AVMs after partial embolization.