Which term correctly describes the parameter calculated in PISA analysis for MR assessment?

Which term correctly describes the parameter calculated in PISA analysis for MR assessment?

• A. Proximal Isovelocity Surface Angle
• B. Distal Isovelocity Surface Area
• C. Proximal Isovelocity Surface Area
• D. Proximal Isovelocity Surface Analysis

Answer: (C)

PISA analysis for MR relies on the Proximal Isovelocity Surface Area, the surface area of the hemispherical flow-convergence region formed around the regurgitant orifice at the aliasing velocity. This area is what you use to estimate the flow rate (Q = 2π r^2 Va). From that flow and the MR jet velocity, you derive the effective regurgitant orifice area and regurgitant volume. The term describes the actual calculated quantity—the area of the proximal isovelocity shell—so it’s the correct descriptor. Names referring to angles, distal surfaces, or mere analysis don’t describe the parameter used in this method.

PISA analysis for MR relies on the Proximal Isovelocity Surface Area, the surface area of the hemispherical flow-convergence region formed around the regurgitant orifice at the aliasing velocity. This area is what you use to estimate the flow rate (Q = 2π r^2 Va). From that flow and the MR jet velocity, you derive the effective regurgitant orifice area and regurgitant volume. The term describes the actual calculated quantity—the area of the proximal isovelocity shell—so it’s the correct descriptor. Names referring to angles, distal surfaces, or mere analysis don’t describe the parameter used in this method.