鼻咽癌放射治疗定位的CT/MRI图像配准辅助装置的研究

目的 研制用于鼻咽癌放射治疗定位的CT/MRI图像配准辅助装置，并且通过组织勾画差异分析使用该装置后所得配准融合图像在临床中的应用意义。方法 在普通的磁共振头颈线圈中设计特定形状的头枕，保持患者在扫描时与CT定位扫描时相同的体位。采用配对t检验分析CT图像与融合图像中腮腺、下颌骨的勾画差异。结果 患者的头颈部CT、MRI图像的配准精度较未使用该装置的图像具有明显的提高，使用该配准图像得到的融合图像、组织结构位置、细节显示准确清晰。左右腮腺体积在CT图像中较CT/MRI融合图像中偏小，左腮腺体积融合和CT图像中的体积分别为（17.78±6.89）cm³和（17.17±7.02）cm³（t=-2.715，P<0.05）；右腮腺体积融合和CT图像中的体积分别为（19.23±8.91）cm³和（17.47±7.42）cm³（t=-2.552，P<0.05）；下颌骨在CT图像中勾画体积较CT/MRI融合图像偏大，左下颌骨体积融合和CT图像中的体积分别为（33.7±5.59）cm³和（34.8±6.27）cm³（t=3.548，P<0.05）；右下颌骨体积融合和CT图像中的体积分别为（34.46±6.08）cm³和（35.38±6.72）cm³（t=3.14，P<0.05）。结论 使用该辅助装置，可以得到头颈部配准融合准确的CT/ MRI的图像，此融合图像对临床医师的组织和病灶勾画具有积极的参考价值。

Development of nasopharyngeal carcinoma radiotherapy positioning of CT/MRI image registration auxiliary device

Objective Developing a CT/MRI image registration assistant device for radiotherapy localization of nasopharyngeal carcinoma, to achieve precise fusion, and by analyzing the differences of the outline to test the application of the registration and fusion image. Methods Design a specific shape pillow for the head-neck coil of MRI, which could keep the patient have the same position form for CT scan. Using paired t-test to analyze the difference of the parotid gland and the mandible. Results After adopting the new device, the registration accuracy has a significant improvement for the head and neck CT and MRI image registration. Comparing two sets of image outline volume, the outlined volume of parotid gland in CT image is smaller than that of CT/MRI fusion image Left parotid gland volume comparison:fusion (17.78±6.89) cm³ and CT(17.17±7.02) cm³(t=-2.715, P<0.05). Right parotid gland volume was (19.23±8.91) cm³ for fusion, and (17.47±7.42) cm³ CT for(t=-2.552, P<0.05), and the size of the mandible was larger than that of CT/MRI fusion image.Left mandible volume was (33.7±5.59) cm³ for fusion, and (34.8±6.27) cm³ for CT (t=3.548, P<0.05). Right mandible volume was (34.46±6.08) cm³ for fusion, and (35.38±6.72) cm³ for CT(t=3.14, P<0.05). Conclusions The accurate image fusion of head and neck CT and, MRI could be achieved with this device, which might be helpful for the delineation of clinical target volume.