A method for automating 3-dimensional proximal isovelocity surface area measurement.
OBJECTIVE
The proximal isovelocity surface area (PISA) is used for the echocardiographic quantification of effective orifice areas in valvular stenosis and regurgitation. Typically measured in 2 dimensions, the PISA relies on the geometric assumption that the shape of flow convergence is a hemisphere and that the orifice is a single circular point. Neither assumption is true. The objective was to develop a method for automating the measurement of the PISA in 3 dimensions and to illuminate the actual shape of the flow convergence pattern and how it changes over time.


METHODS
Retrospective, single-case study.


METHODS
Major urban hospital.


METHODS
This study was based on a single patient undergoing mitral valve replacement.


METHODS
No additional interventions were performed in the patient.


RESULTS
The effective orifice areas calculated from the serial hemispheric, hemi-elliptic, and 3-dimensional (3D) PISAs during diastole were compared with the corresponding planimetric anatomic mitral orifice area. The effective orifice areas based on the manual and automated measurements of 3D PISAs more closely approximated the anatomic orifice than the effective orifice areas calculated using hemispheric or hemi-elliptic PISAs.


CONCLUSIONS
An automated analysis of 3D color Doppler data is feasible and allows a direct and accurate measurement of a 3D PISA, thus avoiding reliance on simplistic geometric assumptions. The dynamic aspect of cardiac orifices also must be considered in orifice analysis.
Department of Anesthesiology, Perioperative Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA. fcobey@gmail.com
Frederick C
FC
Cobey
Jennifer A
JA
McInnis
Brian J
BJ
Gelfand
Mark A
MA
Rapo
Michael N
MN
D'Ambra
D001783:Blood Flow Velocity; D018618:Echocardiography, Doppler, Color / Q000379:methods; D019560:Echocardiography, Three-Dimensional / Q000379:methods; D017548:Echocardiography, Transesophageal / Q000379:methods; D005240:Feasibility Studies; D019918:Heart Valve Prosthesis Implantation / Q000379:methods; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D008946:Mitral Valve Stenosis / Q000000981:diagnostic imaging* / Q000473:pathology / Q000601:surgery; D012189:Retrospective Studies