茎突多层螺旋CT扫描技术探讨

目的:探讨茎突高分辨率CT扫描时改变螺距及准置器宽度对图像质量的影响。方法:将我院50例茎突高分辨率CT扫描患者按准置器宽度为0.75mm和1.5mm分为2组,分别改变螺距0.5~0.8mm后进行扫描。对全部横断扫描图像及VR三维重建后处理图像进行分析评价。结果:多层螺旋CT扫描图像质量优良,能较好地显示正常茎突的细微结构以及异常茎突(过长),准置器宽度为1.5mm时,用同一螺距扫描比准置器宽度为0.75mm时的曝光时间更短,X线剂量当量更低,而图像质量无明显下降。结论:通过调整CT扫描螺距及准置器宽度和采用三维(VR)技术能替代X线平片的检查方法,直观、诊断准确。改变准置器宽度同时改变螺距,能减少X线剂量当量,降低患者的辐射剂量,同时能提供较好质量图像。

Quality Control of Molybdenum Target Radiography in Mammary Examine

Objective To discuss the influences of changing pitch and width of sets to image quality when scanning styloid process with multi-slice CT. Methods 50 patients, scanned styloid proces when pitch changing from 0.5-0.8mm with high differentiation ratio CT, are divided into 2 groups by the width of sets 0.75mm and 1.5mm. Images of coronary plane and that after 3-dimensional reconstruction with VR are analysed and assessed. Results The quality of images scanning with multi-slice spiral CT are good to display the tiny normal structures and abnormal styloid process.Compared to the width of sets at 0.75mm, the machine takes shorter time to scan with same pitch when the width is 1.5mm, and the quality of images do not decrease with lower radiation dose. Conclusion Roentgenography can be replaced by adjusting CT's pitch and width of sets and employing 3 -dimensional technology. It can reduce X -ray dosage and radiation to patients as providing better image quality to changing width of sets when changing pitch.