Spinks T, Jones T, Heather J, Gilardi M
MRC Cyclotron Unit, Hammersmith Hospital, London, UK.
Eur J Nucl Med. 1989;15(11):736-40. doi: 10.1007/BF00631767.
The derivation of physiological parameters in positron tomography relies on accurate calibration of the tomograph. Normally, the calibration relates image pixel count density to the count rate from an external blood counter per unit activity concentration in each device. The quality control of the latter is simple and relies on detector stability assessed by measurement of a standard source of similar geometry to a blood sample. The quality control of the tomographic data depends on (i) detector stability, (ii) uniformity of calibration and normalisation sources and (iii) reproducibility of the attenuation correction procedure. A quality control procedure has been developed for an 8 detector ring (15 transaxial plane) tomograph in which detector response is assessed by acquiring data from retractable transmission ring sources. These are scanned daily and a print out of detector efficiencies is produced as well as changes from a given date. This provides the raw data from which decisions on recalibration or renormalization are made.
正电子断层扫描中生理参数的推导依赖于断层扫描仪的精确校准。通常，校准将图像像素计数密度与每个设备中每单位活度浓度下外部血液计数器的计数率相关联。后者的质量控制很简单，依赖于通过测量与血样几何形状相似的标准源来评估探测器的稳定性。断层扫描数据的质量控制取决于：（i）探测器稳定性；（ii）校准源和归一化源的均匀性；（iii）衰减校正程序的可重复性。已经为一台8探测器环（15个横断面）断层扫描仪开发了一种质量控制程序，其中通过从可伸缩传输环源获取数据来评估探测器响应。这些源每天进行扫描，并生成探测器效率的打印输出以及自给定日期以来的变化情况。这提供了用于做出重新校准或重新归一化决策的原始数据。
