Calcified vascular plaque specimens: assessment with cardiac dual-energy multidetector CT in anthropomorphically moving heart phantom.
OBJECTIVE
To evaluate whether dual-energy multidetector computed tomography (CT) with image postprocessing techniques enhances accuracy of calcified plaque quantification beyond the scope of single-energy multidetector CT, by using optical coherence tomography (OCT) as the reference standard.


METHODS
Four atherosclerotic specimens were examined with 64-section dual-energy multidetector CT by using a novel dual-detector "double-decker" design, with stacked high- and low-energy detector arrays with 32 x 0.625-mm collimation, at 140 kVp and 400 mAs, acquiring simultaneous and isopedic low- and high-energy data sets. Additionally, combined-energy data sets were calculated, and an enhancement algorithm was proposed. Cardiac motion was simulated by an anthropomorphically moving phantom, and OCT was used as a reference standard for plaque quantification. Univariate general linear model (GLM) analysis was used to compare sizes of plaque calcifications determined with OCT with those determined with dual-energy multidetector CT, and the significance of factors such as cardiac motion was assessed.


RESULTS
GLM analysis revealed that plaque quantification based on low-, high-, and combined-energy data sets differed significantly from that based on OCT (P < .001). Greater data variation occurred in smaller (<8 mm(2)) and larger (>12 mm(2)) calcifications. Comparison of calcified plaque sizes determined with OCT with those determined with the dual-energy multidetector CT enhancement algorithm revealed no significant difference (P = .550). Cardiac activity led to a slight increase in data variation in regard to OCT for corresponding static (mean, 10.2% +/- 3.2 [standard deviation]) and dynamic (13.8% +/- 4.9) dual-energy multidetector CT data sets.


CONCLUSIONS
Dual-energy multidetector CT with novel postprocessing techniques enhanced accuracy of calcified plaque quantification by reducing effects of tissue blooming and beam hardening beyond single-energy multidetector CT.
Boll
Daniel T
DT
Department of Radiology, Duke University Medical Center, DUMC 3808, Durham, NC 27710, USA. daniel.boll@duke.edu
Merkle
Elmar M
EM
Paulson
Erik K
EK
Mirza
Rizvan A
RA
Fleiter
Thorsten R
TR
D000465:Algorithms; D000886:Anthropometry; D002114:Calcinosis; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging* / Q000473:pathology; D006321:Heart / Q000000981:diagnostic imaging*; D019047:Phantoms, Imaging; D041623:Tomography, Optical Coherence; D014057:Tomography, X-Ray Computed / Q000379:methods*