Development of a newly designed surface coil for maxillofacial MR imaging

磁共振成像正在成为识别病变范围和性质的基本诊断方式。在颌面部病变的诊断中，需要广域成像并保持良好的图像质量。尤其是对恶性肿瘤进行增强扫描时，应在不改变接收线圈的情况下同时对眶下至锁骨上区域进行增强扫描。本文研制了一种适用于颌面部成像的新型表面线圈。信号强度在头颈区域的分布也进行了评估。这个线圈基本上由三个矩形线圈组成。第一个矩形环是对称的，覆盖双眉到双耳，然后在胸锁乳突肌上运行，并在胸锁关节处连接。第二和第三环与第一环相连并覆盖两个腮腺。为了评估信号强度，将线圈附着在含有硫酸铜溶液的人体形丙烯酸体上，获得42张经轨道至胸锁关节的轴向横向图像。基于幻体矢状面图像的信号强度，对每个图像进行标定，并评估信号强度的空间分布。采用同样的方法对常规头圈和颈圈进行评价，进行比较。结果表明，新线圈为颌面部成像提供了足够的质量。

Magnetic resonance imaging is becoming an essential diagnostic modality in recognizing the extent and nature of the lesion.In the diagnosis of maxillofacial lesions, wide area imaging is required with keeping good image quality. Especially when contrast enhancement is applied in malignancies, region including infraorbital to supraclavicular area should be taken simultaneously without changing receiver coils.In this investigation, a new surface coil suitable for the maxillofacial imaging was developed. Distribution of signal intensity in the head and nack region was also evaluated.This coil is basically consisted of three rectangular loops. The first rectangular loop is symmetric, covers both eyebrows to ears, then runs on sternocleidomastoid muscles and joins at sternoclavicular joint. The second and third loops are attached to the first loop and covers both parotid glands.For the evaluation of the signal intensities, the coil was attached to a human body shaped acrylic phantom containing copper sulfate solution and 42 axial transverse images through orbit to sternoclavicular joint was obtained. Based on the signal intensity in the sagittal image of the phantom, each image was calibrated and spatial signal intensity distribution was evaluated.The conventional head coil and neck coil were also evaluated by the same way for the comparison.As a result the new coil gave sufficient quality for the maxillofacial imaging.