Abstract 2205: Comparison of MDCT and the Novel Flat Panel Volume CT for the Quantification of Coronary Artery Calcification and Vessel Dimensions
Background Coronary artery calcification (CAC) prevents exclusion of coronary artery stenosis (CAS) in a significant amount of patients undergoing Coronary Multi Detector Computed Tomography (MDCT). We compared 64-slice MDCT with novel Volume Computed Tomography (VCT) for the measurements of lumen and plaque dimensions in segments with calcified plaque of ex vivo coronary arteries.
Material/Methods Fresh cadaver human heart specimen (n = 3) were imaged sequentially using a 64 slice MDCT (Siemens Sensation 64; 330 ms temporal resolution; 0.6 mm slice collimation; 0.3 mm reconstruction increment; 120 KV, 850 mAs; 512x 512 pixel matrix; intermediate reconstruction kernel [B26f]) and a VCT (Siemens VCT; 18x18cm detector size; 120 KV, 30 mAs, rotation time 19 sec, 0.2 mm slice thickness, 1024x1024 pixel matrix, sharp reconstruction kernel [S95a]) within 48 hours post mortem. The tissue samples were imaged in supine position within a thorax phantom. We determined the number of detectable calcified plaques (> 130 HU) and measured volume, mean density and Agatston Score of each calcified plaques as well as the Agatston score. In addition, the lumen and vessel area at the location of the highest degree of luinal narrowing and a reference site were measured.
Results Overall, more calcified plaques distinguished by VCT (n = 15) as compared to MDCT (n = 10) Mean volume of calcified plaque and Agatston Score was higher in MDCT compared to VCT (245 ± 622 mm3 vs. 9 ± 9mm3; p < 0.05 and 578 vs. 197, p < 0.01; respectively) while mean plaque density was higher in VCT as compared to MDCT (371 ± 89 HU vs. 632 ± 202; p < 0.01, respectively) ) The lumen area at the reference site and site of greatest luminal narrowing were smaller in MDCT as compared to VCT (0.16 ± 0.06cm2 vs. 0.18 ± 0.06; p = n.s. and 0.07 ± 0.05 cm2 vs. 0.10 ± 0.06 cm2; p < 0.05; for MDCT and VCT, respectively) resulting in a significant reduction of the degree of stenosis by VCT (66.2% vs. 44.5%)
Conclusion Improved spatial resolution of VCT dramatically reduces blooming artifacts of CAC, which may eliminate calcified plaque as a source of overestimation of the degree of coronary artery stenosis.