A novel fully automated method for mitral regurgitant orifice area quantification
File(s)
Published version
Author(s)
Type
Journal Article
Abstract
Background: Effective regurgitant orifice area (EROA) in mitral regurgitation (MR) is difficult to quantify.
Clinically it is measured using the proximal isovelocity surface area (PISA) method, which is intrinsically
not automatable, because it requires the operator to manually identify the mitral valve orifice. We introduce
a new fully automated algorithm, (“AQURO”), which calculates EROA directly from echocardiographic colour
M-mode data, without requiring operator input.
Methods: Multiple PISA measurements were compared to multiple AQURO measurements in twenty patients
with MR. For PISA analysis, three mutually blinded observers measured EROA from the four stored video
loops. For AQURO analysis, the software automatically processed the colour M-mode datasets and analysed
the velocity field in the flow-convergence zone to extract EROA directly without any requirement for manual
radius measurement.
Results: Reproducibility, measured by intraclass correlation (ICC), for PISA was 0.80, 0.83 and 0.83 (for 3 observers
respectively). Reproducibility for AQURO was 0.97. Agreement between replicate measurements calculated
using Bland-Altman standard deviation of difference (SDD) was 21,17 and 17mm2
for the three
respective observers viewing independent video loops using PISA. Agreement between replicate measurements
for AQURO was 6, 5 and 7mm2
for automated analysis of the three pairs of datasets.
Conclusions: By eliminating the need to identify the orifice location, AQURO avoids an important source of
measurement variability. Compared with PISA, it also reduces the analysis time allowing analysis and averaging
of data from significantly more beats, improving the consistency of EROA quantification.
AQURO, being fully automated, is a simple, effective enhancement for EROA quantification using standard
echocardiographic equipment.
Clinically it is measured using the proximal isovelocity surface area (PISA) method, which is intrinsically
not automatable, because it requires the operator to manually identify the mitral valve orifice. We introduce
a new fully automated algorithm, (“AQURO”), which calculates EROA directly from echocardiographic colour
M-mode data, without requiring operator input.
Methods: Multiple PISA measurements were compared to multiple AQURO measurements in twenty patients
with MR. For PISA analysis, three mutually blinded observers measured EROA from the four stored video
loops. For AQURO analysis, the software automatically processed the colour M-mode datasets and analysed
the velocity field in the flow-convergence zone to extract EROA directly without any requirement for manual
radius measurement.
Results: Reproducibility, measured by intraclass correlation (ICC), for PISA was 0.80, 0.83 and 0.83 (for 3 observers
respectively). Reproducibility for AQURO was 0.97. Agreement between replicate measurements calculated
using Bland-Altman standard deviation of difference (SDD) was 21,17 and 17mm2
for the three
respective observers viewing independent video loops using PISA. Agreement between replicate measurements
for AQURO was 6, 5 and 7mm2
for automated analysis of the three pairs of datasets.
Conclusions: By eliminating the need to identify the orifice location, AQURO avoids an important source of
measurement variability. Compared with PISA, it also reduces the analysis time allowing analysis and averaging
of data from significantly more beats, improving the consistency of EROA quantification.
AQURO, being fully automated, is a simple, effective enhancement for EROA quantification using standard
echocardiographic equipment.
Date Issued
2013-07-01
Date Acceptance
2011-11-27
Citation
International Journal of Cardiology, 2013, 166 (3), pp.688-695
ISSN
1874-1754
Publisher
Elsevier
Start Page
688
End Page
695
Journal / Book Title
International Journal of Cardiology
Volume
166
Issue
3
Copyright Statement
© 2011 Elsevier Ireland Ltd. Open access under CC BY-NC-ND license.
Subjects
Science & Technology
Life Sciences & Biomedicine
Cardiac & Cardiovascular Systems
Cardiovascular System & Cardiology
CARDIAC & CARDIOVASCULAR SYSTEMS
Mitral valve regurgitation
Echocardiography
Blood flow velocity
Automated analysis
ISOVELOCITY SURFACE-AREA
FLOW CONVERGENCE REGION
VALIDATION
MODEL
PISA
Publication Status
Published