Improvement of Image Quality and Diagnostic Performance by an Innovative Motion-Correction Algorithm for Prospectively ECG Triggered Coronary CT Angiography.

Zhen-Nan Li,Kun Liu,Zhi-Hui Hou,Ashley H Parinella,Hong-Bing Yan,Yang Gao,Zhi-Qiang Wang,Bin Lu,Chao-Wei Mu,Wei-Hua Yin,Jonathon A Leipsic,Xiaoming Yang

doi:10.1371/journal.pone.0142796

Abstract

ObjectiveTo investigate the effect of a novel motion-correction algorithm (Snap-short Freeze, SSF) on image quality and diagnostic accuracy in patients undergoing prospectively ECG-triggered CCTA without administering rate-lowering medications.Materials and MethodsForty-six consecutive patients suspected of CAD prospectively underwent CCTA using prospective ECG-triggering without rate control and invasive coronary angiography (ICA). Image quality, interpretability, and diagnostic performance of SSF were compared with conventional multisegment reconstruction without SSF, using ICA as the reference standard.ResultsAll subjects (35 men, 57.6 ± 8.9 years) successfully underwent ICA and CCTA. Mean heart rate was 68.8±8.4 (range: 50–88 beats/min) beats/min without rate controlling medications during CT scanning. Overall median image quality score (graded 1–4) was significantly increased from 3.0 to 4.0 by the new algorithm in comparison to conventional reconstruction. Overall interpretability was significantly improved, with a significant reduction in the number of non-diagnostic segments (690 of 694, 99.4% vs 659 of 694, 94.9%; P<0.001). However, only the right coronary artery (RCA) showed a statistically significant difference (45 of 46, 97.8% vs 35 of 46, 76.1%; P = 0.004) on a per-vessel basis in this regard. Diagnostic accuracy for detecting ≥50% stenosis was improved using the motion-correction algorithm on per-vessel [96.2% (177/184) vs 87.0% (160/184); P = 0.002] and per-segment [96.1% (667/694) vs 86.6% (601/694); P <0.001] levels, but there was not a statistically significant improvement on a per-patient level [97.8 (45/46) vs 89.1 (41/46); P = 0.203]. By artery analysis, diagnostic accuracy was improved only for the RCA [97.8% (45/46) vs 78.3% (36/46); P = 0.007].ConclusionThe intracycle motion correction algorithm significantly improved image quality and diagnostic interpretability in patients undergoing CCTA with prospective ECG triggering and no rate control.

Highlights

Coronary computed tomography angiography (CCTA) is widely used as a noninvasive imaging tool for identification and exclusion of obstructive coronary artery disease (CAD)
Prospective ECG triggering CCTA has emerged as an alternative to retrospective ECG gating for coronary artery disease evaluation, and this new method significantly decreases radiation dose while maintaining diagnostic image quality [4,16,17,18]
We evaluated the impact of a motion-correction algorithm on image quality and diagnostic performance in prospective ECG triggering CCTA without rate control

Summary

Introduction

Coronary computed tomography angiography (CCTA) is widely used as a noninvasive imaging tool for identification and exclusion of obstructive coronary artery disease (CAD). Diagnostic accuracy improved as the technology evolved from 16- to 64- to 320-slice machines, along with an increase in temporal and spatial resolution and a decrease in the number of nonassessable coronary segments [1,2]. The impressively high negative predictive value (NPV), both at the patient and vessel level, establishes CCTA as an effective alternative to invasive coronary angiography (ICA) for ruling out CAD [2,3]. Prospective electrocardiogram (ECG) triggering protocols are used as an alternative to the retrospective ECG gating acquisition and iterative reconstruction algorithms are increasingly replacing the filtered back projection, the traditional method of image reconstruction [4,5]. Prospective ECG-triggered lowdose CCTA is increasingly used in clinical routine

Methods

Results

Conclusion