Development of algorithms to grant CT values in a cone-beam computed tomography

在本研究中，在相同的成像条件下，CBCT获得的像素值低于MDCT的CT值。此外，不同的管电压、管电流、视场和被试在视场中的位置对CBCT得到的像素值有显著的影响。这被认为是由于缺乏校准，以及由于设备特定的x射线散射校正，物体在视场外的突出，大锥角，光束硬化效应和CBCT中的图像构建算法。

In this study, pixel values obtained from CBCT were lower than CT values from MDCT in the same imaging conditions. In addition, pixel values obtained from CBCT made significant differences by various tube voltages, tube currents, FOVs and positions of the subject in the FOV. These were thought to be due to a lack of calibration and to be due to the device-specific correction of X-ray scattering, the protrusion of the subject outside the FOV, the large cone angle, the beam hardening effects and the image construction algorithm in CBCT.