Quantification of Multiple Mitral Regurgitant Jets: An In Vitro Validation Study Comparing Two- and Three-Dimensional...

Area of Science:

• Cardiovascular Imaging
• Echocardiography
• Hemodynamics

Background:

• The accuracy of the proximal isovelocity surface area (PISA) method for quantifying mitral regurgitation (MR) with multiple jets remains unclear.
• Evaluating different 2D and 3D PISA methods using 3D color Doppler data is crucial for improving MR assessment.

Purpose of the Study:

• To assess the accuracy of various 2D and 3D PISA methods in quantifying mitral regurgitation (MR) with multiple jets.
• To compare the performance of different PISA calculation approaches against a reference flowmeter.

Main Methods:

• Simulated regurgitant volumes (Rvols) using a pulsatile pump and phantom with single/double orifices.
• Acquired 3D color Doppler data sets using transthoracic (TTE) and transoesophageal echocardiography (TEE).
• Calculated Rvols using 2D PISA (hemispheric, hemicylindric) and 3D integrated PISA methods.

Main Results:

• A fusion of PISA was observed with narrow-spaced orifices, leading to underestimation or overestimation of Rvol with standard 2D hemispheric models.
• A combined 2D approach (hemisphere, hemicylinder with single/double bases) showed improved precision in Rvol quantification.
• Three-dimensional integrated PISA demonstrated the highest accuracy in quantifying Rvol across both TTE and TEE acquisitions.

Conclusions:

• The 2D combined approach and integrated 3D PISA are superior to conventional hemispheric methods for quantifying MR with double orifices.
• These advanced PISA methods provide valuable tools for the challenging assessment of MR in cases with multiple regurgitant jets.