摘要
Abstract
Objective To investigate the CT weighted dose index measurement and its influence on the image quality of PET/CT under different tube voltage. Methods In the tube respectively voltage of 140, 120, 100, 80 kV and other conditions, we used PET/CT system to scan the simulate performance of the body and the CT dose phantom body of Catphan?500 CT. The related characters of the CT image were measured. Meanwhile, the CT dose index of weighted (CTDIw) under different tube voltage and the CT dose index of volume (CTDIvol) under given pitches were measured and calculated. Results The high contrast resolution of the CT images were not affected by the tube voltage. However, with the increase of the tube voltage, the low contrast resolution of the CT images, CTDIvol, the uniform and noise performance of the CT images were increased. When in low contrast resolution of 0.30%, 0.50% and 1.00%, the contrast of the images increased with the increasing of the tube voltage. The CT image uniformity also increased with the increasing of tube voltage. The changes was in a small range when the tube voltage was in 120~140 kV and the changes was in a bigger range in 80~100 kV. The CTDIvol increased linearly with the increasing of the tube voltage, while improving performance was nonlinear rules. Conclusion With the reduction of tube voltage, the CT dose of PET/CT is also reduced, and the appropriate dose of CT dose not affect the quality of CT image when the CT dose is more than a certain value.关键词
管电压/图像质量/辐射剂量/正电子发射断层摄影术/体层摄影术Key words
tube voltage/image quality/radiation dose/positron emission tomography/tomography分类
医药卫生
