Bailey D L, Jones T
MRC Cyclotron Unit, Hammersmith Hospital, DuCane Rd., London, W12 0HS, UK.
Eur J Nucl Med. 1997 Jun;24(6):660-4. doi: 10.1007/BF00841405.
Calibration for three-dimensional positron emission tomography (3D PET) using a uniform cylinder and cross-calibration with aliquots requires correction for scatter and attenuation. Thus the accuracy of the calibration is dependent on the scatter correction method, and on the applicability of the scatter correction for different regions of the body. A method has been developed which provides a calibration which does not require correction for scatter or attenuation, making it generally applicable and independent of the scatter correction. The method has been previously described for measurement of the absolute sensitivity of tomographic devices. This approach has been extended to give a calibration of the PET camera "in air" in units of kBq/pixel. The reconstructed images are multiplied by this factor to give accurate activity concentrations, after attenuation and scatter correction. The method has been used with a fully 3D filtered backprojection (reprojection) algorithm and iterative convolution-subtraction scatter correction on data from an ECAT 953B. Using this method 3D PET images have been calibrated to within +/-5% accuracy, but this is highly dependent on the accuracy of the scatter correction. The method described here is practical and provides a means of calibrating a 3D PET system without the need for correction for scatter or attenuation of the calibration data.
使用均匀圆柱体对三维正电子发射断层扫描（3D PET）进行校准以及对 aliquots 进行交叉校准需要对散射和衰减进行校正。因此，校准的准确性取决于散射校正方法以及散射校正在身体不同部位的适用性。已经开发出一种方法，该方法提供的校准不需要对散射或衰减进行校正，从而使其具有普遍适用性且与散射校正无关。该方法先前已用于测量断层扫描设备的绝对灵敏度。此方法已扩展到以 kBq/像素为单位对 PET 相机“在空气中”进行校准。在进行衰减和散射校正后，将重建图像乘以该因子以得到准确的活度浓度。该方法已与完全三维滤波反投影（重投影）算法以及对来自 ECAT 953B 的数据进行迭代卷积减法散射校正一起使用。使用此方法，3D PET 图像已校准至 +/-5% 的准确度范围内，但这高度依赖于散射校正的准确性。这里描述的方法很实用，并且提供了一种在无需对校准数据的散射或衰减进行校正的情况下校准 3D PET 系统的方法。
