Loughran B, Ionita C, Bednarek D, Rudin S
Toshiba Stroke Research Center, Universityat Buffalo (SUNY) School of Med., Buffalo, NY.
Med Phys. 2012 Jun;39(6Part4):3632. doi: 10.1118/1.4734746.
A brain tissue surrogate material was needed to fill the anatomical cavity of a skull to create a phantom for use in simulated Neuro-EIGI procedures. To enable diagnostic and interventional procedure simulation, the BIM must fit into and be congruous with the interior surface of the skull, be reusable, and allow the implantation of vascular phantoms. The material must reasonably reproduce the automatic technique parameter selections observed during Neuro-EIGI procedures.
We formulated a putty- like material to be used as the BIM. Its x-ray attenuation properties were evaluated by comparison of the fluoroscopic and radiographic technique parameters automatically selected for a BIM-filled skull on a Toshiba Infinix angiographic C-arm unit to those of a solid anthropomorphic head phantom at various projection angles. The same comparison was made between the skull phantom without BIM in the cavity and the anthropomorphic head phantom. The BIM linear attenuation coefficient was calculated and compared to that of PMMA, a common tissue analog plastic.
The BIM keeps its shape, is moldable and reusable, and is congruent to the skull's interior surfaces. It allows for insertion and interchange of various custom vascular phantoms at proper anatomic locations. Addition of the BIM to the skull cavity improves the matching of the automatically selected parameters to those of the anthropomorphic phantom by an average of 96.3% for mAs and by 4.2% for kVp in fluoroscopy mode and by 88.6% and 9.0%, respectively, in DSA mode. The BIM's experimental and theoretical linear attenuation coefficient for the RQA5 spectrum differed from PMMA's by about 30%.
Despite the difference in attenuation coefficients between the PMMA and BIM, the BIM is a good surrogate material for Neuro-EIGI research as shown by its properties of congruity, reusability, and device implantation, along with the demonstrated improvement of automatically selected technique parameters. Supported in part by: NIH Grants R01-EB008425, R01-EB002873, and an equipment grant from Toshiba Medical Systems Corp.
需要一种脑组织替代材料来填充颅骨的解剖腔，以创建用于模拟神经血管介入造影成像（Neuro-EIGI）程序的体模。为了实现诊断和介入程序模拟，该脑内模型（BIM）必须适合并与颅骨内表面相符，可重复使用，并允许植入血管体模。该材料必须合理再现神经血管介入造影成像程序中观察到的自动技术参数选择。
我们配制了一种用作脑内模型的油灰状材料。通过比较在东芝Infinix血管造影C形臂单元上为填充有BIM的颅骨自动选择的透视和放射成像技术参数与在不同投影角度下实体人体头部体模的参数，评估其X射线衰减特性。对腔内无BIM的颅骨体模和人体头部体模进行了相同的比较。计算了BIM的线性衰减系数，并与常见的组织模拟塑料聚甲基丙烯酸甲酯（PMMA）的线性衰减系数进行比较。
BIM保持其形状，可塑形且可重复使用，并且与颅骨内表面相符。它允许在适当的解剖位置插入和更换各种定制的血管体模。在颅骨腔中添加BIM后，在透视模式下，自动选择的参数与人体体模参数的匹配度在毫安秒（mAs）方面平均提高了96.3%，在千伏峰值（kVp）方面提高了4.2%；在数字减影血管造影（DSA）模式下，分别提高了88.6%和9.0%。BIM在RQA5光谱下的实验和理论线性衰减系数与PMMA的相差约30%。
尽管PMMA和BIM之间的衰减系数存在差异，但BIM具有相符性、可重复使用性和设备植入性等特性，并且自动选择的技术参数得到了改善，因此是神经血管介入造影成像研究的良好替代材料。部分得到以下支持：美国国立卫生研究院（NIH）授予的R01-EB008425、R01-EB002873拨款，以及东芝医疗系统公司的设备拨款。
