Hähnel S, Nguyen-Trong T H, Rohde S, Hartmann M, Braun C, Sartor K, Heiland S
Division of Neuroradiology, Department of Neurology, University of Heidelberg Medical Center, Im Neuenheimer Feld 400, D 69120 Heidelberg, Germany.
J Neuroradiol. 2006 Apr;33(2):75-80. doi: 10.1016/s0150-9861(06)77234-0.
To assess the appearance of carotid artery stents at 3.0 Tesla contrast enhanced magnetic resonance angiography (CE-MRA) as compared with 1.5 Tesla.
19 stents (GUIDANT Acculink, GUIDANT Dynalink, BOSTON SCIENTIFIC SMART Neuroform, GUIDANT Omnilink, EV3 Protege, BOSTON SCIENTIFIC Carotid Wallstent, ABBOTT Xact) of different materials (nitinol, stainless steal, cobalt alloy) and different sizes (4.0 mm-10.0 mm) were investigated regarding their appearance on CE-MRA at 3.0 Tesla and at 1.5 Tesla. For each stent artificial lumen narrowing (ALN) was calculated based on a pixel-by-pixel profile of the contrast-to-noise-ratio giving an objective indicator for the size of the evaluable stent diameter.
Only in two stents (Omnilink 7.0 mm, Omnilink 10.0 mm) was ALN higher at 3.0 Tesla relative to 1.5 Tesla. In all other stents ALN at 3.0 Tesla was the same or even lower as compared with 1.5 Tesla. In contrast to the ferromagnetic stents where ALN was typically higher than 85%, in most of the nitinol stents (Acculink, Dynalink, Neuroform, Protege) ALN was below 35%. In the Xact stents ALN was generally 100% at 1.5 Tesla and ranged between 31.8% and 100% at 3.0 Tesla.
CE-MRA after carotid artery stenting is considerably impaired by ALN both at 1.5 Tesla and at 3.0 Tesla. Nevertheless, CE-MRA is well suited for the examination of carotid artery stents made of nitinol at both field strengths. Stent manufacturers should be aware of potential artifacts caused by their stents during noninvasive diagnostic methods such as CE-MRA.
评估3.0特斯拉对比增强磁共振血管造影（CE-MRA）与1.5特斯拉相比时颈动脉支架的表现。
研究了19个不同材料（镍钛合金、不锈钢、钴合金）和不同尺寸（4.0毫米至10.0毫米）的支架（GUIDANT Acculink、GUIDANT Dynalink、BOSTON SCIENTIFIC SMART Neuroform、GUIDANT Omnilink、EV3 Protege、BOSTON SCIENTIFIC Carotid Wallstent、ABBOTT Xact）在3.0特斯拉和1.5特斯拉CE-MRA上的表现。对于每个支架，基于对比度噪声比的逐像素轮廓计算人工管腔狭窄（ALN），给出可评估支架直径大小的客观指标。
仅在两个支架（Omnilink 7.0毫米、Omnilink 10.0毫米）中，3.0特斯拉时的ALN相对于1.5特斯拉更高。在所有其他支架中，3.0特斯拉时的ALN与1.5特斯拉相比相同甚至更低。与铁磁支架中ALN通常高于85%不同，大多数镍钛合金支架（Acculink、Dynalink、Neuroform、Protege）的ALN低于35%。在Xact支架中，1.5特斯拉时ALN通常为100%，3.0特斯拉时介于31.8%至100%之间。
颈动脉支架置入术后的CE-MRA在1.5特斯拉和3.0特斯拉时均受到ALN的显著影响。然而，CE-MRA在两个场强下都非常适合检查由镍钛合金制成的颈动脉支架。支架制造商应意识到其支架在诸如CE-MRA等非侵入性诊断方法期间可能引起的伪影。
