Plaque quantification not reproducible across software platforms

Currently available noncalcified plaque quantification software offers good intraplatform reproducibility but poor interplatform reproducibility, according to a study published in the January 2014 issue of the American Journal of Roentgenology.

Manually distinguishing and quantifying plaque burden, which may aid in future individualized risk stratification and therapeutic monitoring of acute coronary syndrome using contrast-enhanced coronary CT angiography (CTA), is painstaking. Commercial software algorithms have been conceived to side step this challenge and produce automated threshold-based noncalcified coronary artery plaque quantification.

“However,” wrote the study’s lead author, Shane Oberoi, MD, of the Ludwig-Maximilians-University Hospital in Munich, and colleagues, “the reproducibility of noncalcified plaque quantification across different software platforms has not been evaluated to our knowledge and data on intraplatform reproducibility are limited. The prospect of using coronary CTA for therapeutic monitoring—that is, for determining progression or regression of noncalcified plaque burden—stipulates sufficient reproducibility to provide meaningful serial assessments.”

The study’s authors evaluated identical coronary CTA datasets of 47 patients with noncalcified coronary artery plaques using three dedicated software solutions--Aquarius (TeraRecon), Cirulation (Siemens), and Vitrea (Vital Images)--in order to evaluate the reproducibility of noncalcified artery plaque burden quantification from coronary CTA across different commercial analysis platforms.

Results revealed that differences in per-vessel and per-patient noncalcified plaque volumes on intraplatform repeated measurements were found to be statistically insignificant for the three software programs. Vitrea had a significantly higher log volume than Aquarius in the quantitative volumetric measurement at low attenuation. The results at medium-attenuation level were the same except that the log volumes for Aquarius and Circulation were not significantly different. Aquarius had significantly higher log volumes than Circulation. The Pearson coefficient between Aquarius and Circulation was 0.677, 0.672 between Aquarius and Vitrea, and 0.550 between Circulation and Vitrea.

“Our results imply that currently available analysis software does not allow reproducible quantification of noncalcified plaque burden across different software platforms,” wrote Oberoi and colleagues. “Our findings suggest that automated noncalcified coronary artery plaque burden analysis from coronary CTA should be conducted only on identical software systems if multiple or serial measurements are desired. To facilitate clinical interchangeability of results and sustain vendor independence, the introduction of industry standards might be desirable and consequently support broader clinical adoption.”