论文标题
用于超高分辨率成像的混合CT系统的在线几何校准
Online geometric calibration of a hybrid CT system for ultrahigh-resolution imaging
论文作者
论文摘要
由标准CT扫描仪和与患者体内接触的低调光子计数检测器插入物组成的混合成像系统已用于在有限体积的患者胸部扫描中产生超高分辨率图像。根据需要将检测器插入物放在患者床上，而不附着。因此，其在扫描仪中的位置和方向取决于患者的位置和扫描设置。为了允许准确的图像重建，我们设计了一种使用基准标记的检测器插入物和CT扫描仪的相对几何形状的方法。该方法使用迭代注册算法将从检测器插入的重建体积与并发CT扫描的标记对齐。在获得相对于CT扫描仪的检测器插入仪的精确几何信息之后，将两个互补图像集汇总在一起，以创建带有减少伪影的详细图像。
A hybrid imaging system consisting of a standard CT scanner and a low-profile photon-counting detector insert in contact with the patient's body has been used to produce ultrahigh-resolution images in a limited volume in chest scans of patients. The detector insert is placed on the patient bed as needed and not attached. Thus, its position and orientation in the scanner is dependent on the patient's position and scan settings. To allow accurate image reconstruction, we devised a method of determining the relative geometry of the detector insert and the CT scanner for each scan using fiducial markers. This method uses an iterative registration algorithm to align the markers in the reconstructed volume from the detector insert to that of the concurrent CT scan. After obtaining precise geometric information of the detector insert relative to the CT scanner, the two complementary sets of images are summed together to create a detailed image with reduced artifacts.
