Written by Andrea Fields MHA, RDCS

A Complete Guide to Performing MR PISA!

Over the past two months, we have provided ample amount of information regarding evaluation of mitral regurgitation. The goal of this blog is to discuss the 3 variables we use in quantifying the severity of mitral regurgitation (MR) and explain the first method to obtaining these values!

3 Measurable Variables

  1. Effective Regurgitant Orifice Area (EROA): measure of lesion severity
  2. Regurgitant Volume (RVol): measure of severity of volume overload
  3. Regurgitant Fraction (RF): ratio of RVol to forward SV specific to patient

EROA & RVol are the two values that provide the strongest predictors of clinical outcomes.

3 Methods to Quantifying MR

We are able to obtain these values in three different methods:

  1. PISA Method (Flow Convergence)
  2. Stroke Volume Method (Pulsed Wave Doppler)
  3. Volumetric Method 

For this blog, we are going to cover the first method: PISA

PISA Method

Proximal Isovelocity Surface Area (PISA) is a method based off of flow convergence. If you missed our prior blog over flow convergence, you can find it here.

This method is based off of the conservation of mass:

flow through the regurgitant orifice = flow through the isovelocity surface

It assumes the radius (r) occurs at the same time as the peak regurgitant velocity.

PISA method is able to provide us with:

  1. Regurgitant Flow
  2. EROA
  3. Regurgitant Volume

The regurgitant flow rate is the amount of regurgitant flow per second being pushed back into the LA. It’s the product from the surface area of the hemisphere and the aliasing velocity.

How to Perform PISA

There are two steps to performing the PISA method.

Step 1: Measuring the Radius (r)

  1. Zoom MV
  2. Color Doppler
  3. Shift Color Baseline DOWN (TTE) to 20-40 cm/sec
  4. Freeze to obtain mid-systolic frame
  5. Measure radius (r): point of color aliasing to vena contracta

 

MR PISA Radius

Step 2: CW Doppler MR Jet Velocity & Measure

  1. Zoom MV/LA
  2. Color Doppler
  3. CW Doppler MR
  4. VTI MR Velocity

MR PISA CW VTI Doppler

PISA Equations

Thankfully our machines do the math for us! But if you are the type of person that likes to know the breakdown process of how we obtain our outcome values, here are the equations!

PISA MR Equations

PISA Measurement Values

PISA Reference Values

PISA Limitations

  • CW Doppler & PISA Radius must be obtained at same point in cardiac cycle
  • PISA method is calculated from a single-frame image
  • Overestimation occurs if the jet is not holosystolic
  • RVol more appropriate measurement to utilize if jet is not holosystolic
  • Eccentric jets present challenge (angulation & inability record jet)

Case Example

Now that we understand how to perform the PISA method, let’s walk through a case example!

MR Radius

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Summary

This week we have provided you with a clear and easy understanding of how to perform PISA.  Keep an eye out for next week’s blog that will cover the second method to quantifying mitral regurgitation!

We love to hear feedback from our readers! Our goal at CardioServ is to provide our readers a clear understanding of proper ways to evaluate and quantifying structures within the heart!

Andrea Fields MHA, RDCS

Stay Connected: LinkedInFacebookTwitterInstagram

 

 

 

References: 

Zoghbi, W. A., MD, FASE, & Adams, D., RCS, RDCS, FASE. (2017). Recommendations for Noninvasive Evaluation of Native Valvular Regurgitation. JASE, 30, 4th ser., 1-69. Retrieved June 12, 2017.

EROAMitral RegurgitationMitral ValvePISARegurgitant VolumeRegurgitation Quantification

LET US KNOW WHAT YOU THINK...

Tadesse Gemechuhow d
excellent
Tammy Anderson
Thanks
Shaiful Islam
Excellent.
Shrinivas
I love to hear more equations which r really difficult to perform and memorize
Pradyumna Godbole
Thank you so much. May God bless you for this service to society.
provenzal antonio
excellent
Dr. sheikh rayees
This is very helpful for someone like me, who has a keen interest in cardiology....thanks
Dr. sheikh rayees
iam loving it
Nikita
Finally I understood this method! Had a problem with aliasing velocity, because on my machine, I should enter it manually.
Cardioserv
Happy we could help. You bring up a great point. If the ultrasound machine does not have a PISA measurement package built into the system, manual calculations will have to be performed. When manually performing these, you will have to enter the 'aliasing velocity' into the equation. You can find this by looking at the color Doppler scale, after you have adjusted your baseline accordingly (DOWN for TTE, UP for TEE). The number shown either below/above the scale (depending on which way you moved the baseline) will be your aliasing velocity you place within the equation. Thanks for your comment!
Phillip D Amato
Great insight on PISA.
MOHAMED ELDESSOUKY
Thank you very much very clear and concise keep up this good work
catalin mihai
Congratulations for this blog! I think radius appreciation is a little subjective, as do vena contracta measurement . Which would be exactly the measurement boundaries, but please practically , possibly through a practical example . Thank you for your effort and great help !
JVA
Neat & easy to follow tutorial! Thanks!. Noteworthy all values should be in cm/s, not m/s as PKV reg = Step 2 & 3, So: you should div by 640 cm/s not 6.4 m/s!. Regards!
Susan Nader
Is there a printable version we could download?
Cardioserv
We will have all the MR material available on our CME platform. You can download this material in a printable format within our CME platform.
Irina
Very comprehensive , thanks for sharing ☺️
Ivan Kamenov
So elegant again. Best wishes!
Mona Dhakal
Very nice explanation
Dana Parker
Thanks for the concise, complete review of mitral regurg. evaluation by PISA method. Well done.

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