Abstract 20041: Fully Automated Wall Motion and Thickening Scoring System for Myocardial Perfusion SPECT: Development and Validation in Large Population
Aim: Objective assessment of wall motion (M) and thickening (T) will aid in diagnosis of Coronary Artery Disease (CAD) from Myocardial Perfusion SPECT (MPS). We aimed to develop and validate a fully automated M /T segmental scoring system for MPS.
Methods: 100 normal gated stress/rest Tc-99m sestamibi MPS scans from patients with low-likelihood of CAD (Llk) were used to derive the regional normal M/T ranges, which were found to be linearly dependent on ventricular volumes. A new automatic scoring algorithm incorporated these relationships locally in polar map coordinates and automatically derived 17-segment M (scale 0–5) and T (scale 0–3) scores. We validated this new method in 630 consecutive Tc-99m stress MPS studies in patients with suspected CAD and available correlating angiography [including 111 triple vessel disease (3VD) cases], and 341 LLk studies. Two independent observers with 12 and 30 years of experience in nuclear cardiology, blinded to clinical and angiographic data, scored M /T in 17-segments for all 971 studies.
Results: Computation time was < 1 sec per case. In the angiography group there was a high correlation between the summed scores (averaged for 2 observers) and automatic scores with r=0.91 (slope=0.95, offset=0.2; p < 0.0001) for M and r=0.84 (slope=0.90, offset=0.28 for T; p < 0.0001). Weighted kappa was 0.63 for M and 0.52 for T, with expected agreement of 89% (M) and 91% (T) in individual segments (n=10710). Weighted kappa between 2 experts was 0.45 for M and 0.52 for T. The normalcy rate in LLk cases was 96% for automated M and 99% for T (summed score < 3). The receiver operator characteristics area under the curve (ROC-AUC) for the detection of 3VD in angiographic cases is given in the table.
Conclusions: Fully automated scoring of MPS regional ventricular function is highly correlated with expert visual scoring, can outperform individual experienced observers in the detection of 3VD by wall thickening from MPS and avoids inter-observer variability.
- © 2010 by American Heart Association, Inc.