CAJ | 학술논문

目的比较容积高分辨率CT(VHRCT)与常规高分辨率CT(CHRCT)的图像质量,探讨VHRCT的可行性.方法对Catphan 412模具行VHRCT及CHRCT扣描,测量和记录图像的空间分辨率、噪声及放射剂量并进行比较;对32例患者行VHRCT及CHRCT检查,对图像质量进行评分并比较.模具部分采用配对t检验比较噪声的差异;临床部分采用Wilcoxon配对符号秩和检验比较图像质量的差异.结果模具研究中,VHRCT横断面图像的空间分辨率与CHRCT相同,均为11 LP/cm,其z轴分辨率为12 LP/cm.剂量相近时,VHRCT的噪声为(69.18±2.77)HU,大于CHRCT的噪声(54.62±2.12)HU,(t=-15.929,P＜0.01);噪声相近时,VHRCT的剂量较CHRCT增加19.09 mGy.临床研究中,VHRCT与CHRCT横断面图像的质量评分分别为3.22与3.24,差异无统计学意义(Z=-0.319,P＞0.05),VHRCT与CHRCT冠状面蕈建图像的质量评分分别为3.05与1.88,差异有统计学意义(Z=-5.088,P＜0.01).结论对于64层CT,VHRCT的横断面图像质量接近CHRCT,多平面重组图像具有高分辨率可广泛应用,其扫描剂量尚有待优化.
목적 비교용적고분변솔CT(VHRCT)여상규고분변솔CT(CHRCT)적도상질량,탐토VHRCT적가행성.방법 대Catphan 412모구행VHRCT급CHRCT구묘,측량화기록도상적공간분변솔、조성급방사제량병진행비교;대32례환자행VHRCT급CHRCT검사,대도상질량진행평분병비교.모구부분채용배대t검험비교조성적차이;림상부분채용Wilcoxon배대부호질화검험비교도상질량적차이.결과 모구연구중,VHRCT횡단면도상적공간분변솔여CHRCT상동,균위11 LP/cm,기z축분변솔위12 LP/cm.제량상근시,VHRCT적조성위(69.18±2.77)HU,대우CHRCT적조성(54.62±2.12)HU,(t=-15.929,P＜0.01);조성상근시,VHRCT적제량교CHRCT증가19.09 mGy.림상연구중,VHRCT여CHRCT횡단면도상적질량평분분별위3.22여3.24,차이무통계학의의(Z=-0.319,P＞0.05),VHRCT여CHRCT관상면심건도상적질량평분분별위3.05여1.88,차이유통계학의의(Z=-5.088,P＜0.01).결론 대우64층CT,VHRCT적횡단면도상질량접근CHRCT,다평면중조도상구유고분변솔가엄범응용,기소묘제량상유대우화.
Objective To compare the image quality between volumetric high-resolution CT (VHRCT)and conventional high-resolution CT(CHRCT),and investigate the feasibility of VHRCT.Methotis Catphan 412 phantom was scanned with protocols of CHRCT and VHRCT on a set of GE Lightspeed VCE.The spatial-resolution(LP/cm),noise(standard deviation iu an ROI)and radiation dose (CTDI)were recorded for each CT scan.Difference of noise between CHRCT and VHRCT were evaluated by paired t test.In clinical study.32 patients were scanned with VHRCT and CHRCT protocols.The image quality of CHRCT and VHRCT was rated and compared.The quality difference between CHRCT and VHRCT was assessed by Wilcoxon paired signed rank sum test.Results In phantom study.the in-plane spatial-resolution of both VHRCT and CHRCT was 11 LP/cm for axial images and 12 LP/cm for coronal reformatted images.The noise of VHRCT and CHRCT was(69.18±2.77)HU and(54.62±2.12)HU respectively(t=-15.929.P＜0.01)at the same dose level.The radiation dose of VHRCT was 19.09 mGy higher than CHRCT at the same noise level.In clinical study.the quality assessment scores of VHRCT axial images and CHRCT axial images were 3.22 and 3.24 respectively.with no significant difference(Z=-0.319,P＞0.05).The qualily assessment scores of VHRCT coronal reformatted images and CHRCT coronal reformatted images were 3.05 and 1.88 respectively with significant difference(Z=-5.088.P＜0.01).Conclusion The image qualitv of VHRCT cross-sectional image is similar to that of CHRCT.Muhiplanar images with high resolution of VHRCT are recommended.The radiation dose of VHRCT remains to be optimized.