Medical radiation technology, Shizuoka College of Medicalcare Science, Hamamatsu-city, Shizuoka, Japan.
Faculty of Health Science and Technology, Kawasaki University of Medical Welfare, Okayama, Japan.
J Appl Clin Med Phys. 2023 Feb;24(2):e13897. doi: 10.1002/acm2.13897. Epub 2023 Jan 7.
During a single scan using computed tomography, an X-ray tube orbits along a 360°-circular path around the patient. A scan obtained using the half-cylindrical type phantoms with a radiochromic film sandwiched in between reveals a pixel value map illustrating the two-dimensional (2D) dose distribution. A three-dimensional (3D) dose distribution can be obtained with a 360° rotation of the 2D dose map. This study evaluates the concept and methodology of creating a 3D dose map to develop a phantom with a radiochromic film for obtaining the 3D dose distribution. The coronal and axial plane dose distributions were also evaluated. A single scan computed tomography image obtained using a half-cylindrical type of acrylic phantom with a sandwiched radiochromic film was studied. The diameters of the phantoms were 10 and 16 cm, and their lengths were 30 cm. A 2D image of the XR-QA2 film was obtained using an image scanner and image processing software. A red channel image was used to obtain the 3D dose distribution using a computing platform. A pseudo color was applied to the red channel image from which cross-sectional color images were obtained. Half of the cross-sectional pixel data were rotated by 360° to generate the data for each axial plane. The image created was saved, and a 3D pixel value map was constructed. The dose measurement procedure for the 3D dose distribution was developed using half-cylindrical acrylic phantoms with a radiochromic film.
在单次 CT 扫描中，X 射线管沿着患者周围的 360°圆形路径旋转。使用夹在中间的放射变色胶片的半圆柱型体模获得的扫描会显示一个像素值图，说明二维（2D）剂量分布。通过对 2D 剂量图进行 360°旋转，可以获得三维（3D）剂量分布。本研究评估了创建 3D 剂量图以开发具有放射变色胶片以获取 3D 剂量分布的体模的概念和方法。还评估了冠状面和轴平面剂量分布。研究了使用夹有放射变色胶片的半圆柱型亚克力体模获得的单次 CT 扫描图像。体模的直径为 10 和 16 厘米，长度为 30 厘米。使用图像扫描仪和图像处理软件获得 XR-QA2 胶片的 2D 图像。使用计算平台使用红色通道图像获得 3D 剂量分布。对红色通道图像应用伪彩色以获得横截面彩色图像。通过将一半的横截面像素数据旋转 360°来生成每个轴平面的数据。创建的图像被保存，并构建了 3D 像素值图。使用带有放射变色胶片的半圆柱型亚克力体模开发了 3D 剂量分布的剂量测量程序。
