Background In addition to high spatial (0.4 mm) and temporal resolution (83 ms), Dual Source CT (DSCT) allows simultaneous imaging with two different x-ray energies. This may be beneficial for tissue characterization.
Objectives. To determine the accuracy of ex vivo atherosclerotic plaque characterization with DSCT and to assess the CT attenuation of various plaque components depending on X-ray energy.
Materials and Methods. 18 atherosclerotic vessels of coronary, carotid and iliac arteries obatined from autopsy were analyzed by DSCT. Each lumen of the vessels was filled with contrast media (30X Imeron 350). The collimation was 2X64X0.6 mm, rotation time was 330 msec., temporal resolution was 83 msec. Data sets were obtained using a tube voltage of 80, 100, 120, and 140 kV. The x.-ray attenuation of lipid-rich plaque, fibrous plaque, calcified plaque and contrast-enhanced lumen were determined for all x-ray energies by comparison to histology at 25 sites. In addition, cross-sectional images were reconstructed with 0.75 mm slice thickness and 0.4 mm increment. 26 slices at 10 mm interval were analyzed by comprehensive color-coding according to CT number.
Results. There were significant differences among CT attenuations of lipid-rich, fibrous and calcified plaque using 80, 100, 120, and 140 kV (Table
, p<0.01), respectively. The averaged ratio of CT attenuation of lipid-rich, fibrous plaque, and calcified plaque to the Contrast-enhanced lumen for 80kV and 140kV were −16%, 11%, 14%, respectively (p<0.05). Lipid-rich plaque was well-differentiated with lumen attenuation in all energies.
Conclusions. The relationships between lumen enhancement and each plaque component were different as changing the x-ray energy level. Using of varying x-ray energy, DSCT may able to detect atherosclerotic plaque and characterization of plaque components.
The Attenuation on Different Energy
A Method to Improve Electron Density Measurement of Cone-Beam CT Using Dual Energy Technique