ERO = Flow/Peak velocity = 178/450 = 0.39 cm²

R Vol = EROA x TVI = 0.39 cm² x 210 cm = 82 mL

Limitations

• PISA shape affected
  • by the aliasing velocity
  • in the case of non-circular orifice
  • by systolic changes in regurgitant flow
  • by adjacent structures (flow constrainment)
• PISA radius is more a hemi-ellipse
• Errors in PISA measurement are squared
• Inter-observer variability
• Not valid for multiple jets
• Feasibility limited by aortic valve calcifications

Usefulness/Advantages

• Can be used in eccentric jet
• Quantitative: estimate lesion severity (EROA) and volume overload (R Vol)