Aneurysm clip MR artifacts. Titanium versus stainless steel and influence of imaging parameters

Purpose: The aim of this study was to evaluate the extent to which titanium aneurysm clips could improve the quality of MR imaging compared with stainless steel clips, and to determine whether the clip artifacts could be reduced by controlling certain MR imaging parameters in frequently used pulse sequences. Material and Methods: The metal artifacts induced by 3 aneurysm clips were compared in 3 pulse sequences. The clips were: a Yasargil titanium aneurysm clip FT 752 T; a Yasargil standard aneurysm clip FE 752 K; and, for comparison, a ferromagnetic Scoville aneurysm clip En-58J. The pulse sequences were: spin echo (SE); gradient echo (GE); and fast SE. An evaluation was made of 3 imaging parameters with regard to their influence on the size of the metal artifacts. The parameters were: bandwidth; echo time (TE); and echo-train length. Results: The titanium clip showed artifacts that were about 60% smaller than those from the stainless steel clip. The only parameter that influenced artifact size to any major degree was bandwidth in the SE sequences but not in the GE sequences. GE sequences induced larger artifacts than SE sequences and showed larger artifacts with longer TE. Conclusion: Titanium aneurysm clips reduced MR artifacts by approximately 60% compared to stainless steel clips. Artifacts were further reduced by using SE-based sequences with a high bandwidth or, if necessary, GE sequences with a low TE. (orig.)