Diagnostic Value Of Dual-layer Detector Spectral CT In Prostate Cancer

Objective:To explore the diagnostic value of dual-layer detector spectral CT in prostate cancer(PCa).Methods:Retrospectively collected 53 patients with prostate cancer(PCa)confirmed by pathology in our hospital from October 2019 to December 2022,and underwent spectral CT enhanced scanning before treatment.After workstation post-processing,based on arterial and venous phase images,conventional 120 k Vp polyenergetic image(PI),40 ke V virtual monoenergetic image(VMI),iodine density maps,Z?effective maps and iodine overlay maps were obtained,and then the films were read independently and blindly by two radiologists.The lesions were observed and the subjective and objective quality of the images were evaluated.Then the patients were divided into two groups according to pathological Gleason score(GS): middle-low risk group(33 cases)and high risk group(20 cases).Then ROI was drawn on the maximum diameter level of the tumor on the spectral CT image,and the CT value,iodine concentration(IC)and effective atomic order value(Zeff)of the lesions were measured,and the normalized iodine concentration(NIC)and arterial enhancement fraction(AEF)were calculated.The differences of spectral CT quantitative parameters between the two groups of PCa were compared,and the correlation between spectral CT quantitative parameters and Gleason classification was analyzed by spearman correlation.The receiver operating characteristic(ROC)curve was drawn to evaluate the diagnostic effect of quantitative parameters on high risk PCa.Results:1.The signal-to-noise ratio(SNR),contrast-to-noise ratio(CNR)and subjective image quality scores of venous 40 ke V VMI were significantly higher than those of venous 120 k Vp PI,and the difference was statistically significant.There was no significant difference between venous 40 ke V VMI subjective image quality scores and MRI images,and there was a good consistency between the two radiologists(kappa value was 0.687).2.The CT value in arterial phase,Zeff in arterial phase,IC in arterial phase,NIC in arterial phase,Zeff in venous phase,IC in venous phase and AEF were positively correlated with Gleason grade(r = 0.387,0.460,0.483,0.430,0.353,0.324 and 0.291,respectively,P<0.05).There was no significant correlation between CT value and NIC in venous phase and Gleason grade.The lesion area and quantitative parameters of spectral CT in high risk group PCa were significantly higher than those in middle-low risk group PCa(P<0.05,except venous CT value).The area under the ROC curve of arterial phase IC to distinguish between high-risk group and middle-low risk group PCa was the largest(0.814),the sensitivity was 85.0%,and the specificity was 81.8%.Conclusion:1.Spectral CT can significantly improve the detection of PCa and the significance of lesions compared with conventional CT,and 40 ke V VMI in venous phase is the best.2.The quantitative parameters of spectral CT of PCa can reflect its pathological grade and risk to a certain extent,which provides more objective basis for predicting the biological behavior and prognosis of PCa and helping clinical decision-making,and provides a new idea for non-invasive examination of PCa.