Balancing Speed and Accuracy in Cardiac Magnetic Resonance Function Post-Processing: Comparing 2 Levels of Automation in 3 Vendors to Manual Assessment.

Gert J.H Snel,David Sosnovik,Vincent M Van Deursen,Niek H.J Prakken,Sharon Poort,Birgitta K Velthuis,Christopher T Nguyen,Riemer H.J.A Slart,Rudi A.J.O Dierckx,Ronald J.H Borra

doi:10.3390/diagnostics11101758

Abstract

Automating cardiac function assessment on cardiac magnetic resonance short-axis cines is faster and more reproducible than manual contour-tracing; however, accurately tracing basal contours remains challenging. Three automated post-processing software packages (Level 1) were compared to manual assessment. Subsequently, automated basal tracings were manually adjusted using a standardized protocol combined with software package-specific relative-to-manual standard error correction (Level 2). All post-processing was performed in 65 healthy subjects. Manual contour-tracing was performed separately from Level 1 and 2 automated analysis. Automated measurements were considered accurate when the difference was equal or less than the maximum manual inter-observer disagreement percentage. Level 1 (2.1 ± 1.0 min) and Level 2 automated (5.2 ± 1.3 min) were faster and more reproducible than manual (21.1 ± 2.9 min) post-processing, the maximum inter-observer disagreement was 6%. Compared to manual, Level 1 automation had wide limits of agreement. The most reliable software package obtained more accurate measurements in Level 2 compared to Level 1 automation: left ventricular end-diastolic volume, 98% and 53%; ejection fraction, 98% and 60%; mass, 70% and 3%; right ventricular end-diastolic volume, 98% and 28%; ejection fraction, 80% and 40%, respectively. Level 1 automated cardiac function post-processing is fast and highly reproducible with varying accuracy. Level 2 automation balances speed and accuracy.

Highlights

Cardiovascular magnetic resonance (CMR) imaging is the reference standard for noninvasive assessment of ventricular volumes, function, and left ventricular (LV) mass [1].Conventional post-processing by manually contour-tracing a stack of short-axis slices in end-diastolic and end-systolic phase is time-consuming [2,3]
We assessed the benefit of manually adjusting Level 1 automated basal tracings using a standardized protocol
Level 1 automated post-processing was ten times faster with higher reproducibility compared to manual contour-tracing, big differences resulted in few measurements that were considered accurate with large variation between software packages

Summary

Introduction

Cardiovascular magnetic resonance (CMR) imaging is the reference standard for noninvasive assessment of ventricular volumes, function, and left ventricular (LV) mass [1].Conventional post-processing by manually contour-tracing a stack of short-axis slices in end-diastolic and end-systolic phase is time-consuming [2,3]. Commercially available artificial intelligence software has the ability to reduce post-processing time while increasing reproducibility [4], and several studies already showed promising results for Level 1 automated assessment [5,6,7,8,9,10]. The major challenge in measurement accuracy is basal tracing; dealing with cardiac through-plane motion combined with the complexity of basal anatomy which varies between individuals [3,11]. These introduce disagreement with manual reference tracings, leading to different standards being used between sites, especially for the right ventricle (RV) [5,8,12]. Level 1 automated measurements can contain significant vendor-specific relative standard error in all slices [6,8,13]

Methods

Discussion

Conclusion