Akira Kurata, Presenter: Nothing to Disclose

Koen Nieman MD, PhD, Abstract Co-Author: Speakers Bureau, Siemens AG Speakers Bureau, Toshiba Corporation Research Grant, Bayer AG Research Grant, General Electric Company

Tsuyoshi Sakamoto RT, Abstract Co-Author: Nothing to Disclose

Gabriel P. Krestin MD, PhD, Abstract Co-Author: Consultant, General Electric Company Research Grant, General Electric Company Research Grant, Bayer AG Research Grant, Siemens AG Speakers Bureau Siemens AG

Teruhito Mochizuki MD, Abstract Co-Author: Nothing to Disclose

Teruhito Kido MD, PhD, Abstract Co-Author: Nothing to Disclose

Hiroshi Higashino MD, PhD, Abstract Co-Author: Nothing to Disclose

Mitsunori Abe, Abstract Co-Author: Nothing to Disclose

Quantification of myocardial ischemia has prognostic value, and is important for therapeutic decision making in patients with coronary artery disease (CAD). Voronoi’s algorithm is a mathematical algorithm that divides area (2-dimentional; 2D) or space (3-dimentional; 3-D) between pre-determined points or lines based on the shortest distance to those points/lines. This study aimed to estimate the myocardial area at risk (MAAR) using coronary computed tomography angiography (CCTA) based 3-D myocardial segmentation in comparison with stress myocardial perfusion imaging by single photon emission computed tomography (SPECT).

Thirty-four patients with coronary artery disease underwent 128-slice coronary CTA, stress-rest thallium-201 SPECT and coronary angiography (CAG). CTA based MAAR was defined as the sum of all CAG stenosis (>50%) related territories (the ratio of the left ventricular volume). Using the automated quantification software (17-segment model, 5-point scale), SPECT-MAAR was defined as the number of segment with a score above zero as ratio to the total 17 segments by summed stress (SSS), difference (SDS) score map, and comprehensive SPECT interpretation with either SSS or SDS best correlating the CAG findings. Results were compared by Pearson's correlation coefficient.

Forty-nine stenoses were observed in 102 major coronary territories. Mean value of CTA based MAAR was 28.3±14.0%. SPECT based MAAR was 30.1±6.1% (SSS), 20.1±15.8% (SDS) and 26.8±15.7% (comprehensive assessment), respectively. CTA based MAAR was significantly related to SPECT based MAAR (r=0.531, for SSS; r=0.494, for SDS; r=0.814, for comprehensive assessment, P<0.05 in each). Coronary CTA based MAAR predicted SPECT based MAAR as reference within an error of ± 10% in 21 of 34 (61.7%, for SSS), 22 of 34 (64.7%, for SDS), and 29 of 34 (85.3%, for comprehensive assessment), respectively

Coronary CTA based Voronoi algorithm myocardial segmentation reliably quantifies SPECT based MAAR in patients with obstructive CAD.

3-D automated myocardial segmentation using CTCA can quantify myocardial area at risk in patients with CAD without stress test.

Kurata, A, Nieman, K, Sakamoto, T, Krestin, G, Mochizuki, T, Kido, T, Higashino, H, Abe, M, 3-D Quantification of the Myocardial Area at Risk Using Coronary CT Angiography and Voronoi Algorithm Based Myocardial Segmentation.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14009842.html