Khurshid Khawar, Berger Kevin L, McGough Robert J
Annu Int Conf IEEE Eng Med Biol Soc. 2009;2009:5805-8. doi: 10.1109/IEMBS.2009.5335188.
Computed Tomography (CT) is used for the attenuation correction of Positron Emission Tomography (PET) to enhance the efficiency of data acquisition process and to improve the quality of the reconstructed PET data in the brain. Due to the use of two different modalities, chances of misalignment between PET and CT images are quite significant. The main cause of this misregistration is the motion of the patient during the PET scan and between the PET and CT scans. This misalignment produces an erroneous CT attenuation map that can project the bone and water attenuation parameters onto the brain, thereby under- or over-estimating the attenuation. To avoid the misregistration artifact and potential diagnostic misinterpretation, automated software for PET/CT brain registration has been developed. This software extracts the brain surface information from the CT and PET images and compensates for the translational and rotational misalignment between the two scans. This procedure has been applied to the dataset of a patient with visible perfusion defect in the brain, and the results show that the CTAC produced after the image registration eliminates that hypoperfusion artifact caused by the erroneous attenuation of the PET images.
计算机断层扫描（CT）用于正电子发射断层扫描（PET）的衰减校正，以提高数据采集过程的效率，并改善大脑中重建PET数据的质量。由于使用了两种不同的模态，PET和CT图像之间出现错位的可能性相当大。这种配准错误的主要原因是患者在PET扫描期间以及PET和CT扫描之间的运动。这种错位会产生错误的CT衰减图，该图可能会将骨骼和水的衰减参数投射到大脑上，从而低估或高估衰减。为了避免配准错误伪影和潜在的诊断错误解读，已经开发了用于PET/CT脑配准的自动化软件。该软件从CT和PET图像中提取脑表面信息，并补偿两次扫描之间的平移和旋转错位。此程序已应用于一名大脑中存在明显灌注缺陷的患者的数据集，结果表明图像配准后产生的CTAC消除了由PET图像错误衰减引起的灌注不足伪影。
