Puskar Pattanayak MBBS, FRCR, Presenter: Nothing to Disclose

Karen Rodriguez, Abstract Co-Author: Nothing to Disclose

Davis M. Vigneault BS, Abstract Co-Author: Nothing to Disclose

David A. Bluemke MD, PhD, Abstract Co-Author: Research support, Siemens AG

Both hard (calcium) and soft plaque can be readily assessed to determine the overall volume of coronary plaque using MDCT. However to date, the scan-rescan reproducibility of plaque volume has not been previously reported.

A total of 30 coronary arteries and 82 segments were analyzed for ten volunteer subjects (mean age, 63.7). Within a short period (mean, 20 days), study subjects (mean age 63.7) underwent baseline and repeat coronary CT angiography (CCTA) on a 320 detector scanner. CTA images were analyzed for calcium and noncalcified plaque using Medis QAngio semi-automated software. A second reader interpreted the follow-up CT. Total and plaque subtype amounts indexed by segment length were measured. Plaque quantification was optimized using both standard and “narrow vessel wall thickness” setting settings using an adaptive algorithm that adjusted for coronary lumen density. 

Mean radiation dose per scan was 4.5msv. Total plaque burden had good intra-observer reproducibility (Intra-class Correlation Coefficient, ICC: 0.84). Total plaque indexed by length showed excellent inter-observer reproducibility (ICC 0.94). Calcified plaque showed excellent intra-observer and inter-observer reproducibility (ICCs 0.98 to 0.99). Fibrous fatty and necrotic core plaque had good intra-observer (ICCs 0.74 and 0.78) and inter-observer reproducibility (ICCs 0.96 and 0.83). Fibrous plaque was poorly reproducible (ICCs 0.03 and 0.65 for intra- and inter-observer measurements).  

Calcified plaque has excellent reproducibility and correlates highly with Agatston calcium scores. Scan-rescan reproducibility was very good for plaque indexed by length, fibrous fatty and necrotic core plaque. Only fibrous plaque is poorly reproducible.  

Total coronary plaque volume by coronary CT angiography shows very good scan-rescan reproducibility. This measure should be useful as a patient centered index of atherosclerosis for clinical trials and therapy.

Pattanayak, P, Rodriguez, K, Vigneault, D, Bluemke, D, Total Coronary Plaque Volume: Reproducibility Using CCTA.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14017720.html