Honkanen Petri, Frösen Juhana K, Abo-Ramadan Usama, Hernesniemi Juha A, Niemelä Mika R
Neurosurgery Research Group, Biomedicum Helsinki, Helsinki, Finland.
Neurosurgery Research Group, Biomedicum Helsinki, Helsinki, Finland ; Department of Neurosurgery, Helsinki University Central Hospital, Helsinki, Finland.
Surg Neurol Int. 2014 May 21;5:74. doi: 10.4103/2152-7806.132960. eCollection 2014.
Better diagnostic tools to identify rupture-prone saccular intracranial aneurysms (sIA) are needed. Inflammation and luminal thrombus associate with degeneration and rupture of the sIA wall. Iron-uptake has been detected in the inflammatory cells of the sIA wall and thrombus is the likely source of this iron. We investigated ex vivo the use of magnetic resonance imaging (MRI) to detect iron accumulation and luminal thrombus in giant sIAs.
Giant sIAs (n = 3) were acquired from microsurgical operations, fixed with formalin, embedded in agar and imaged at 4.7T. Samples were sectioned maintaining the orientation of the axial plane of MRI scans, and stained (hematoxylin-eosin and Prussian blue).
All three giant sIAs showed a degenerated hypocellular wall with both mural and adventitial iron accumulation and displayed different degrees of luminal thrombus formation and thrombus organization. Signal intensity varied within the same sIA wall and associated with iron accumulation in all tested sequences. Wall areas with iron accumulation had significantly lower signal to noise ratio (SNR) compared with areas without iron accumulation (P = 0.002). Fresh and organizing thrombus differed in their MRI presentation and differed in signal intensity of the aneurysm wall (P = 0.027).
MRI can detect ex vivo the accumulation of iron in giant sIA wall, as well as fresh and organizing luminal thrombus. These features have been previously associated with fragile, rupture-prone aneurysm wall. Further studies of iron accumulation as a marker of rupture-prone aneurysm wall are needed.
需要更好的诊断工具来识别易破裂的颅内囊状动脉瘤（sIA）。炎症和管腔内血栓与sIA壁的退变和破裂相关。在sIA壁的炎症细胞中已检测到铁摄取，血栓可能是这种铁的来源。我们在体外研究了磁共振成像（MRI）检测巨大sIA中铁蓄积和管腔内血栓的应用。
从显微手术中获取3个巨大sIA，用福尔马林固定，包埋在琼脂中，并在4.7T下成像。将样本切片，保持与MRI扫描轴向平面的方向一致，然后进行苏木精-伊红和普鲁士蓝染色。
所有3个巨大sIA均显示出退变的细胞减少壁，伴有壁层和外膜铁蓄积，并表现出不同程度的管腔内血栓形成和血栓机化。在所有测试序列中，同一sIA壁内的信号强度各不相同，且与铁蓄积相关。与无铁蓄积的区域相比，有铁蓄积的壁区域的信噪比（SNR）显著更低（P = 0.002）。新鲜血栓和机化血栓在MRI表现上不同，且动脉瘤壁的信号强度也不同（P = 0.027）。
MRI能够在体外检测巨大sIA壁中铁的蓄积以及新鲜和机化的管腔内血栓。这些特征先前已与脆弱、易破裂的动脉瘤壁相关。需要进一步研究将铁蓄积作为易破裂动脉瘤壁的标志物。
