Most common calculations used in echocardiography
| Parameter | Description | Calculation |
| Sound | Speed of sound | V = f · λ |
| Sound velocity constant in soft tissue | 1540 = f · λ |
| Nearfield length | L = r² / λ |
| Frequency | f = 1 / T |
| Doppler | Doppler formula | ΔF = 2·f0·v / c · cosα |
| Doppler shift | PRF = 2 · f doppler |
| Nyquist limit | Aliasing = PRF / 2 |
| Qs/Qp | Shunt calculation | πr² · VTI lvot / πr² · VTI rvot |
| MVA | Pressure half time | MVA = 220/PHT |
| TVA | Pressure half time | TVA= 190/PHT |
| MPI | Tei index | MPI = (IVCT + IVRT) / ET |
| PISA | Flowrate | πr² · Vn |
| ERO | Effective regurgitant orifice | Flowrate / Vmax MR |
| Regurgitation Volume | ERO · VTI MR |
| Output | Stroke volume | πr² · VTI lvot |
| Cardiac output | SV · HF |
| AVA | Continuity Equation | AVA = πr² · VTI lvot / VTI AoV |
| Pressure | Modified Bernoulli equation | ΔP = 4 (V2² - V1²) |
| Simplified Bernoulli equation | ΔP = 4 · V² |
| PA pressure | Systolic | 4 x (TR Vmax)² + estimated RAP |
| Diastolic | 4 x (PR Ved)² + estimated RAP |
| Mean | 0.3 x systolic PAP + 0.6 x diastolic PAP |
| | 90 - (0.62 x AccT) when AccT < 120ms |
| | 4 x (PR Vmax)² + estimated RAP |
| | TR PGmean + estimated RAP |
| LV | LV Volume | (IVS + LVIDd + PW)³ |
| Blood volume | (LVIDd)³ |
| Myocardial volume | (IVS + LVIDd + PW)³ - (LVIDd)³ |
| Relative wall thickness | 2 x PWd / LVIDd |
| LV mass | 0.8(1.04((LVIDd+IVSd+PWd)³−LVIDd³))+0.6 |
| LV mass index | LV mass / Body surface area |
References
Armstrong, W.F, Ryan, T, "Physics and Instrumentation" in 'Feigenbaum's Echocardiography', 7th ed, Philadelphia, Lippincott Williams & Wilkins, p.09-p.38
Armstrong, W.F, Ryan, T, "Hemodynamics" in 'Feigenbaum's Echocardiography', 7th ed, Philadelphia, Lippincott Williams & Wilkins, p.217-p.241.