Potential of dual-energy computed tomography to characterize atherosclerotic plaque: ex vivo assessment of human coronary arteries in comparison to histology

Photon counting spectral CT component analysis of coronary artery atherosclerotic plaque samples

“…Indeed, lack of spatial resolution of conventional human-sized CT scanners has been reported as a main limitation in coronary wall analysis with dual energy CT scanners. 9 In this publication, the spatial resolution was around 0.4 mm leading to an insufficient depiction between the iodine-filled lumen on one hand and the wall components on the other hand. This lack of spatial resolution is even more critical in the presence of calcified plaques.…”

“…[4][5][6][7][8] These problems are related to the insufficient spatial resolution available with the current clinical system and to the overlaps of the Hounsfield values between iodine and calcifications on one hand and the lipid core and other soft components of the arterial wall on the other hand. Improved differentiation between calcification and iodine was obtained with energy CT. 8,9 Furthermore, photon counting spectral CT has recently been proposed to improve tissue characterization by improving the measurement of the energy dependence of the attenuation of various tissues in comparison with conventional CT scanners. This spectral resolution allows obtaining a map of the iodine concentration (IC) by utilizing its K-edge at 33.2 keV in the X-ray absorption spectrum, as well as an accurate decomposition of the X-ray attenuation into photoelectric absorption (PA) and Compton scattering (CS) instead of a single global attenuation number as provided by conventional CT. [10][11][12] We evaluated the capabilities of a photon counting spectral CT scanner to differentiate between the different components of coronary artery atherosclerotic plaque based on differences in spectral attenuation and iodine-based contrast agent maps.…”

“…Improved differentiation between calcification and iodine was obtained with energy CT. 8,9 Furthermore, photon counting spectral CT has recently been proposed to improve tissue characterization by improving the measurement of the energy dependence of the attenuation of various tissues in comparison with conventional CT scanners. This spectral resolution allows obtaining a map of the iodine concentration (IC) by utilizing its K-edge at 33.2 keV in the X-ray absorption spectrum, as well as an accurate decomposition of the X-ray attenuation into photoelectric absorption (PA) and…”

Spectroscopic (multi-energy) CT distinguishes iodine and barium contrast material in MICE

“…Conventional imaging determines whether plaque is calcified or not. Dual-energy CT can detect the calcium in atherosclerotic plaque, but it cannot distinguish the components of plaque [21]. However, in the future multi-energy imaging of atherosclerotic plaque [4,22] may help characterise the components of plaque in order to determine if it is stable or unstable.…”

Quantitative material characterization from multi‐energy photon counting CT

“…An ideal plaque imaging device would (a) have high spatial resolution to measure plaque morphology, (b) offer multiple tissue classification (lipid, loose fibrous matrix, calcium, dense fibrous tissue) to investigate plaque composition, 5 and (c) be safe for serial studies. While conventional dual-energy CT can provide high resolution, it is not able to provide soft tissue classification 6 and requires relatively high dose levels limiting its use for serial evaluation.…”