Ikeguchi Hiroaki, Shonai Takaharu, Mikami Aya, Yazawa Natsuka, Takahashi Tadashi, Yamada Kouji
Department of Radiology, KKR Sapporo Medical Center.
Nihon Hoshasen Gijutsu Gakkai Zasshi. 2013 Jan;69(1):71-9. doi: 10.6009/jjrt.2013_jsrt_69.1.71.
Homogeneity of static magnetic field (B(0)) is unstable for head and neck magnetic resonance (MR) examination; consequently, chemical shift selective fat suppression becomes inhomogeneous. There is a commercially available additional pad to attenuate the B(0) inhomogeneity, but it is expensive. It has been reported that uncooked rice can be used as a material in the pad, but it has hygienic and weight problems. We searched for a material which can replace the uncooked rice, and evaluated its performance.
After filling various materials into the cylindrical phantom, each material was evaluated by image distortion of gradient filed echo and spin echo single-shot echo planar images. A prototype additional pad was made with a material which showed less image distortion in the phantom experiment and is easily available in clinical examination. For comparison, an uncooked rice pad with the same volume was also prepared. Fat suppressed head and neck magnetic resonance imaging (MRI) of normal volunteers were visually compared when the three additional pads, including the commercial product, were used or not.
The polystyrene ball bullet (BB bullet) was adopted as a material for the additional pad. The improvement of the fat suppression in the head and neck MRI was almost the same between the three additional pads. BB bullet pad was the lightest.
BB bullet can be used as a material of additional pad attenuating the B(0) inhomogeneity instead of uncooked rice.
在头颈部磁共振成像（MR）检查中，静磁场（B(0)）的均匀性不稳定，因此化学位移选择性脂肪抑制变得不均匀。有一种市售的附加垫可用于减弱B(0)不均匀性，但价格昂贵。据报道，生米可用于制作该垫，但存在卫生和重量问题。我们寻找一种可替代生米的材料，并评估其性能。
将各种材料填充到圆柱形体模中后，通过梯度回波和自旋回波单次激发回波平面图像的图像畸变来评估每种材料。用在体模实验中图像畸变较小且在临床检查中容易获得的材料制作了一个原型附加垫。为作比较，还制备了相同体积的生米垫。在使用或不使用包括商业产品在内的三种附加垫时，对正常志愿者的脂肪抑制头颈部磁共振成像（MRI）进行视觉比较。
聚苯乙烯球弹（BB弹）被用作附加垫的材料。三种附加垫在头颈部MRI中脂肪抑制的改善情况几乎相同。BB弹垫最轻。
BB弹可作为替代生米的附加垫材料，用于减弱B(0)不均匀性。
