摘要
Abstract
Objective:To assess the clinical utility of dual-layer spectral detector CT virtual monoenergetic imaging(VMI)combined with a split-bolus contrast protocol in CT urography(CTU).Methods:Ninety-two patients with hematuria undergoing CTU were randomized into an experimental group(46 cases)and a control group(46 cases).The experimental group received an initial 25 mL contrast bolus,followed by a second bolus of 20 mL contrast and 30 mL saline 15 minutes later,undergoing a single corticomedullary-excretory phase scan.The control group underwent unenhanced scanning followed by 100 mL contrast and 30 mL saline injection,with triphasic(cortical,medullary,excretory)scanning.The experimental group's images were reconstructed into 40,50,60,70 keV VMI and mixed-energy images,while the control group's excretory phase images were reconstructed as mixed-energy images.CT values,noise(SD),SNR,and CNR of the two groups were compared via one-way ANOVA.Two radiologists independently scored image quality using the 5-point method,and Kruskal-Wallis H test was used to compare the image quality scores.Results:In the experimental group,VMI images demonstrated a progressive decrease in CT values,SD,SNR,and CNR with increasing energy levels(all P<0.05).No significant differences in SNR or CNR were observed between the mixed-energy images in the control group and the 50 keV VMI images in the experimental group(both P>0.05).Interobserver agreement was excellent.In the experimental group,50 keV VMI images achieved optimal display quality score,while 40 keV VMI images showed superior contrast filling score.The experimental group reduced effective radiation dose to 21.54%of the control group.Conclusions:Dual-layer spectral detector CT VMI with split-bolus protocol enhances CTU image quality while reducing the amount of contrast media and radiation dose,with 40-50 keV VMI providing optimal visualization.关键词
体层摄影术,X线计算机/能谱成像/尿路造影术/造影剂/辐射剂量,图像质量Key words
Tomography,X-ray computed/Spectral imaging/Urography/Contrast media/Radiation dosage/Image quality
