关键词: 静脉造影术, 体层摄影术, X线计算机, 放射摄影术, 双能扫描投影

Abstract: Objective　To investigate the differences of vascular enhancement and image quality between low-kiloelectron volt monochromatic images and low-tube-voltage images at indirect CT venography（ICTV） with dual-source dual-energy CT.Methods　In this retrospective study，50 consecutive patients suspected to have pulmonary thromboembolism（PTE） underwent multislice spiral CT pulmonary arteriography（CTPA） and ICTV by a dual-source dual-energy CT at Tongde Hospital of Zhejiang Province.Two radiologists evaluated 50 kiloelectron volt（keV） monochromatic images（group A） and 80 kVp images（group B） for vessel enhancement，image quality，image noise in the distal inferior vena cava（IVC），right femoral vein（at the level of the inguinal ligament），and right popliteal vein（in the popliteal fossa）．Results　Of the 50 patients，11 were found with venous thromboembolism，and 9 of them had PTE（including 3 also had DVT），2 had isolated DVT.Mean intravascular CT attenuation within the deep vein was significantly higher in group A than in group B（P<0.05）．Although the images of group A had significantly higher image noise than that of group B（P<0.05），there were no significant differences in image quality between the two groups（P>0.05）．Conclusion　Similar image quality with substantially higher venous attenuation was provided by 50 keV monochromatic images from dual-energy CT venography acquisition compared with 80 kVp images.

Key words: Phlebography；Tomography, X-ray computed；Radiography, dual-energy scanned projection