Table 1.
Comparison of patient characteristics (n = 61).
Fig 1.
Axial CTV images obtained using 120 kVp and FBP in a 49-year-old woman with BMI 23.9.
Attenuation value, vein-to-muscle contrast-to-noise ratio and signal-to-noise ratio in this patient were 134.7 HU, 7.2, and 8.2 in the IVC (a), 147.3 HU, 8.6, and 16.6 in the CFV (b), and 121.8 HU, 5.9 and 10.4 in the PV (c). Attenuation values of subcutaneous fat and muscle at the mid-thigh level were also measured using circular ROIs (d). The image quality was subjectively classified as score 4 (good) for the overall image quality and score 1 (optimal) for the image noise by the two readers. *CTV computed tomographic venography, FBP filtered back projection, BMI body mass index, HU Hounsfield unit, IVC inferior vena cava, CFV common femoral vein, PV popliteal vein, ROI region of interest.
Fig 2.
Axial CTV images obtained using 80 kVp and SAFIRE in a 75-year-old woman with BMI 23.2.
Attenuation value, vein-to-muscle contrast-to-noise ratio and signal-to-noise ratio in this patient were 237.5 HU, 12.6, and 9.3 in the IVC (a), 211.4 HU, 10.6, and 16.0 in the CFV (b), and 192.4 HU, 9.2 and 11.7 in the PV (c). Attenuation values of subcutaneous fat and muscle at the mid-thigh level were also measured using circular ROIs (d). Intraluminal filling defect (arrow) was detected in the right popliteal vein, which was diagnosed as DVT. The overall image quality scores and image noise scores were 5 (excellent) and 1 (optimal) for reader 1 and 4 (good) and 1 (optimal) for reader 2. *CTV computed tomographic venography, SAFIRE sinogram-affirmed iterative reconstruction, BMI body mass index, HU Hounsfield unit, IVC inferior vena cava, CFV common femoral vein, PV popliteal vein, ROI region of interest.
Fig 3.
Comparison of axial CTV images obtained using (a) 120 kVp and FBP and (b) 80 kVp and SAFIRE from representative patient of each group (BMI 22.0 and 24.1, respectively). (a) Intraluminal filling defect (arrow) was detected in the left femoral vein, which was diagnosed as DVT. Attenuation value of right femoral vein, vein-to-muscle contrast-to-noise ratio and signal-to-noise ratio were 168.5 HU, 12.3 and 11.9. (b) Intraluminal filling defects (arrows) were detected in both femoral veins, which were diagnosed as DVT. Attenuation value of right common femoral vein, vein-to-muscle contrast-to-noise ratio and signal-to-noise ratio were 184.0 HU, 6.5 and 11.1 (figure not shown). Subjective scores for overall image quality and image noise were 4 (good) and 1 (optimal) in (a) and 4 (good) and 1 (optimal) in (b). *CTV computed tomographic venography, FBP filtered back projection, SAFIRE sinogram-affirmed iterative reconstruction, BMI body mass index, DVT deep vein thrombosis, HU Hounsfield unit.
Table 2.
Results of the objective analysis of two different CTV protocols.
Table 3.
Results of the subjective analysis of two different CTV protocols.
Table 4.
Comparison of radiation dose of two different CTV protocols.