Enter the ICA PSV and the CCA PSV into the calculator. The calculator will evaluate the ICA/CCA PSV ratio. 

ICA/CCA PSV Ratio Calculator

Ratio (any 2 values)
Ratio (from PSV)

Enter any 2 values to calculate the missing value. If using ultrasound velocities: ICA/CCA ratio = ICA PSV ÷ CCA PSV.

Medical note: This calculator is for educational use only and cannot diagnose or grade carotid stenosis (clinical interpretation typically uses multiple ultrasound parameters plus plaque/imaging findings). Do not delay or change medical care based on this tool. If you have possible stroke/TIA symptoms (face droop, arm weakness, speech difficulty), seek emergency care immediately.

ICA/CCA PSV Ratio Formula

ICR = ICA / CCA

Variables:

  • ICR is the ICA/CCA PSV ratio (unitless)
  • ICA is the ICA peak systolic velocity (PSV) (cm/s)
  • CCA is the CCA peak systolic velocity (PSV) (cm/s)

To calculate the ICA/CCA PSV ratio, divide the ICA PSV by the CCA PSV.

How to Calculate ICA/CCA PSV Ratio?

The following steps outline how to calculate the ICA/CCA PSV ratio.

  1. First, determine the ICA PSV. 
  2. Next, determine the CCA PSV. 
  3. Next, gather the formula from above = ICR = ICA / CCA.
  4. Finally, calculate the ICA/CCA PSV ratio.
  5. After inserting the variables and calculating the result, check your answer with the calculator above.

Example Problem : 

Use the following variables as an example problem to test your knowledge.

ICA PSV = 89 cm/s

CCA PSV = 74 cm/s

FAQs

What is the significance of the ICA/CCA PSV Ratio?

The ICA/CCA PSV Ratio is used to compare two values (ICA PSV and CCA PSV). In carotid duplex ultrasound, it is one parameter that may be considered alongside other measurements and imaging findings.

Can the ICA/CCA PSV Ratio be used in medical diagnostics?

The ICA/CCA PSV ratio is commonly used in carotid duplex ultrasound interpretation alongside ICA PSV, ICA EDV, and plaque/gray-scale imaging findings. It should not be used alone to diagnose or grade stenosis.

How can errors in calculating the ICA/CCA PSV Ratio be minimized?

To minimize errors, ensure accurate measurements and units. Using a reliable calculator and double-checking entries can also help reduce inaccuracies.

Are there any limitations to using the ICA/CCA PSV Ratio?

Yes. The ICA/CCA PSV Ratio is a single parameter and has limitations. Contextual understanding and additional data are often necessary for accurate interpretation.