Comparison of the image quality between volumetric and conventional high-resolution CT with 64-slice row CT / 中华放射学杂志

ABSTRACT

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.