The application value of spectral CT venography in the display and staging of deep venous thrombosis in the lower extremity / 实用放射学杂志

ABSTRACT

Objective To investigate the application value of spectral computed tomography venography(CTV)in the display and staging of deep venous thrombosis(DVT)in the lower extremity.Methods Eighty-two patients with CTV were selected and ran-domly divided into group A(42 patients)and group B(40 patients).Group A:tube voltage 120 kVp.Group B:gemstone spectral ima-ging(GSI)mode,reconstruction of 50 keV and iodine(water)maps.The CT and standard deviation(SD)values of the veins were measured,signal-to-noise ratio(SNR)and contrast-to-noise ratio(CNR)were calculated in 120 kVp images of group A and in 50 keV images of group B.Two observers scored the image quality of the 2 groups subjectively,and Kappa test was used to examine the con-sistency.Based on the duration from the occurrence of clinical symptoms,the DVTs were classified.The CT values and iodine con-centration(IC)of DVT were measured in the 120 kVp images of group A and in the iodine(water)maps of group B,respectively.The receiver operating characteristic(ROC)curve was drawn to compare the effectiveness of CT values and IC in diagnosing DVT staging.Results CT values,SNR,and CNR of veins in group B were higher than those in group A(P<0.05).The subjective scores of the two groups were consistent(Kappa=0.926-0.955,P<0.05).The score for the display of veins and thrombus clarity in group B was 5(4,5),which was better than the score of 4(3,4)in group A(P<0.05).The efficiency of IC in diagnosing DVT staging[area under the curve(AUC)=0.973]was better than that of CT values(AUC=0.891).Conclusion The spectral CTV can improve the contrast of lower extremity deep veins and the clarity of thrombus,and can provide more objective indicators for the diagnosis of thrombus staging,which is conducive to accurate clinical diagnosis and treatment.