Table 3 Attenuation and CNR of the best phase for different vessel regions.

From: Imaging of Patients with Complex Hemodialysis Arterio-Venous Fistulas using Time-Resolved Dynamic CT Angiography: Comparison with Duplex Ultrasound

 

Protocol A Low CM Volume

Protocol B Low CM Volume

Protocol C High CM Volume

Protocol D High CM Volume

P-value* High vs low CM Volume

Attenuation (HU)

 Artery

471 ± 66

435 ± 77

561 ± 69

534 ± 102

P < 0.0017

 Shunt

469 ± 65

432 ± 75

557 ± 69

528 ± 103

P < 0.0023

 Vein

204 ± 83

224 ± 55

345 ± 68

325 ± 91

P < 0.0001

 Distal artery

380 ± 68

364 ± 61

461 ± 69

425 ± 108

P < 0.0071

CNR

 Artery

13 ± 3

10 ± 2

14 ± 3

14 ± 4

P < 0.0239

 Shunt

13 ± 3

10 ± 2

14 ± 3

14 ± 3

P < 0.0223

 Vein

5 ± 3

4 ± 2

8 ± 2

8 ± 3

P < 0.0002

 Distal artery

10 ± 2

8 ± 2

11 ± 2

10 ± 4

P < 0.0468

  1. Note – CNR = contrast-to-noise ratio; CM = contrast media.
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