Gur D, Deutsch M, Fuhrman C R, Clayton P A, Weiser J C, Rosenthal M S, Bukovitz A G
University of Pittsburgh, Department of Diagnostic Radiology, Pennsylvania 15261.
Med Phys. 1989 Jan-Feb;16(1):132-6. doi: 10.1118/1.596383.
Two drawbacks in quality of portal radiographs in radiation therapy are their low contrast and low spatial resolution. These are due to the low differential absorption of body tissues at therapeutic energies and to a relatively large radiation source. We used an experimental, high-contrast sensitivity storage phosphor imaging system (Eastman Kodak Co.) to produce portal images. The system consists of a storage phosphor detector, a high-contrast sensitivity laser scanner (12 bit), an image processing module, and a laser printer (12 bit). Patients undergoing radiation therapy treatments had both a conventional portal image and a storage phosphor image taken. Both were displayed side-by-side and were evaluated independently by three radiotherapists according to quality of information to verify the treatment field. Each of the three radiotherapists rated the storage phosphor images to be better (p less than 0.001) than the conventional images. However, rated improvements of low-contrast storage phosphor images of the pelvis and abdomen (40) were significantly lower than those of high-contrast (head, neck, and chest) images (53).
放射治疗中门静脉造影图像质量存在两个缺点，即对比度低和空间分辨率低。这是由于治疗能量下人体组织的微分吸收低以及辐射源相对较大所致。我们使用了一种实验性的高对比度敏感性存储磷光成像系统（伊士曼柯达公司）来生成门静脉图像。该系统由一个存储磷光探测器、一个高对比度敏感性激光扫描仪（12位）、一个图像处理模块和一台激光打印机（12位）组成。接受放射治疗的患者同时拍摄了传统门静脉图像和存储磷光图像。两者并排显示，并由三名放射治疗师根据信息质量独立评估以验证治疗区域。三名放射治疗师中的每一位都认为存储磷光图像比传统图像更好（p小于0.001）。然而，骨盆和腹部低对比度存储磷光图像的评级改善（40）明显低于高对比度（头部、颈部和胸部）图像（53）。
