多层螺旋CT扫描层厚、重建间隔和多平面重建图像质量相关性的实验研究

目的探讨Mx80004层螺旋CT机具有实用价值和理想的多平面重建(MPR)技术参数方法用Mx8000CT机对人结肠标本行6.5mm、5.0mm、3.2mm、2.0mm及1.0mm不同层厚扫描,分别进行2.0mm、1.0mm和0.5mm不同间隔重建,在工作站做肠腔纵切面的MPR(包括CPR)成像对各组MPR图像质量进行评分后作统计学对比分析结果在相同间隔重建的MPR图像中,以层厚越薄得分越高在相同层厚的MPR图像中,重建间隔越小,评分相对越高;0.5mm与1.0mm重建间隔间的图像质量相比无明显统计学差异1.0mm层厚的扫描范围太小,CT剂量指数(CTDI)明显高于其它扫描层厚;2.0mm层厚的扫描范围达88mm,且CTDI与剩余层厚者较接近结论Mx80004层螺旋CT机用2.0mm扫描层厚、1.0mm间隔重建,可获取满意质量的MPR图像,并具有实际操作意义

Experimental Parametric Study of Multiplanar Reconstruction using Multislice Spiral CT

Objective To investigate the practical and ideal parameters for multiplanar reconstruction(MPR) image using Mx8000 4-slice spiral CT unit . Methods The colonic specimens were scanned at different slice thickness ( 6.5 mm,5.0 mm,3.2 mm,2.0 mm and 1.0 mm),the images were reconstructed with 0.5 mm,1.0 mm or 2.0 mm intervals,and MPR in vertical section of intestinal lumen was performed at workstation.The quality of MPR images scored and analysed comparatively.Results The slice thickness of thin scanning,the higher score of MPR images was showed at the same interval reconstruction.Among the imaging at the same slice thickness,the thin interval reconstruction,the higher score,and there was no prominent statistical difference (P>0.05)between the images at 0.5 mm and 1.0 mm interval reconstruction.The scanning extent at 1.0 mm slice thickness was too small,and the CT dose index(CTDI) at 1.0 mm slice thickness was much higher than that of the other slice thickness.The scanning extent at 2.0 mm slice thikcness was 88 mm,and its CTDI was close to that of the other slice thickness.Conclusion The slice thickness of thin scanning,the better quality of its MPR imaging. Reconstruction with appropriate interval makes the MPR imaging better. Scanning with 2.0 mm slice thickness and reconstruction with 1.0 mm interval at Mx8000 unit can obtain satisfactory MPR images with practicality.