Scheck R J, Wendt T, Panzer M
Department of Radiology and Radiotherapy, LMU University of Munich, Germany.
Br J Radiol. 1993 Sep;66(789):801-6. doi: 10.1259/0007-1285-66-789-801.
The potential of digital storage phosphor radiography (SR) to improve image quality of portal radiographs is evaluated. Conventional film radiographs (FR) and corresponding SR verification images of an anthropomorphic phantom and various irradiation ports of patients were obtained with high-energy photon beams. For both techniques conventional films and storage phosphor screens were placed into a cassette with steel screens. Images were evaluated according to contrast and spatial resolution, delineation of anatomical structures, position of shielding blocks and accuracy of field alignments. Evaluation of 33 pairs of SR and FR portal images yielded a superior contrast resolution of SR in 47% (contrast air-soft tissue) and 37% (bone-soft tissue). Thus SR allows quick and easy detectability of anatomical structures as well as a better definition of block positions and field alignments. Shorter exposure times for computed images may result in a reduction of motion artefacts. SR images are indispensable in modern radiation therapy units, as they are instantly available in a computerized network for further image processing and analysis.
评估了数字存储磷光体射线照相术（SR）改善门静脉射线照片图像质量的潜力。使用高能光子束获得了人体模型和患者各种照射野的传统胶片射线照片（FR）以及相应的SR验证图像。对于这两种技术，将传统胶片和存储磷光体屏放置在带有钢屏的暗盒中。根据对比度和空间分辨率、解剖结构的描绘、屏蔽块的位置以及射野对准的准确性对图像进行评估。对33对SR和FR门静脉图像的评估显示，SR在47%（空气-软组织对比度）和37%（骨-软组织对比度）方面具有更高的对比度分辨率。因此，SR能够快速、轻松地检测解剖结构，并更好地确定屏蔽块位置和射野对准。计算机图像的较短曝光时间可能会减少运动伪影。SR图像在现代放射治疗设备中是不可或缺的，因为它们可立即在计算机网络中获取，用于进一步的图像处理和分析。
