Accuracy of attenuation measurement of vascular wall in vitro on computed tomography angiography: Effect of wall thickness, density of contrast medium, and measurement point.
OBJECTIVE
We sought to assess the effects of measurement point, wall thickness, and intravascular density of contrast material on attenuation measurement of vascular wall.


METHODS
We used vascular models (actual attenuation value of the wall: 83 HU) with wall thicknesses of 1.5, 1.0, or 0.5 mm, filled with contrast material of 254, 325, or 400 HU. The 9 vascular models were fixed in an oil-filled container and scanned with a 16-detector computed tomography. The wall attenuation values were measured at 1 point for 0.5-mm thickness models, 3 for 1.0-mm thickness models, and 5 for 1.5-mm thickness models with the same interval of 0.25 mm. Total 20 measurements were done for each point.


RESULTS
For 1.0-mm and 1.5-mm thickness models, wall attenuation progressively increased as the measurement points approached the lumen (P < 0.0001). At all the measurement points for 0.5-mm and 1.0-mm thickness models and the 2 inner measurement points for 1.5-mm thickness models, the densities of contrast material affected the wall attenuations significantly (P < 0.0001). At the midportion for 1.5-mm thickness models, the wall attenuations were not affected by the densities of the contrast material (P = 0.6301), and were 65-68 HU.


CONCLUSIONS
The effects of the intravascular density of contrast material, measurement point, and wall thickness should be considered in the attenuation measurement of the wall.
Suzuki
Shigeru
S
Department of Radiology, Teikyo University School of Medicine, Tokyo, Japan. s-suzuki@med.teikyo-u.ac.jp
Furui
Shigeru
S
Kuwahara
Sadatoshi
S
Kaminaga
Tatsuro
T
Yamauchi
Teiyu
T
Konno
Kumiko
K
Yokoyama
Naoyuki
N
Isshiki
Takaaki
T
D000792:Angiography / Q000379:methods*; D001808:Blood Vessels / Q000502:physiology*; D003287:Contrast Media; D006801:Humans; D066298:In Vitro Techniques; D008955:Models, Cardiovascular; D019047:Phantoms, Imaging; D011856:Radiographic Image Enhancement; D012984:Software; D014055:Tomography, Emission-Computed; D014057:Tomography, X-Ray Computed
D003287:Contrast Media