1. What is the Resistive Index?

The Resistive Index (RI) is a Doppler ultrasound parameter used to assess vascular resistance in various organs. In dogs, it's commonly used to evaluate renal, hepatic, and other organ perfusion, helping to diagnose conditions affecting blood flow.

2. How Does the Calculator Work?

The calculator uses the Resistive Index formula:

Where:

• \( PSV \) — Peak Systolic Velocity (cm/s)
• \( EDV \) — End Diastolic Velocity (cm/s)

Explanation: The RI measures the resistance to blood flow in vessels, with higher values indicating increased vascular resistance.

3. Importance of RI Calculation

Details: RI calculation is important for assessing organ perfusion, diagnosing vascular diseases, monitoring treatment response, and evaluating transplant organ viability in veterinary medicine.

4. Using the Calculator

Tips: Enter PSV and EDV values in cm/s obtained from Doppler ultrasound measurements. Ensure PSV > EDV and both values are positive.

5. Frequently Asked Questions (FAQ)

Q1: What is the normal RI range for dogs?
A: Normal renal RI in dogs is typically between 0.55-0.70, but values may vary depending on the organ being assessed and the dog's age.

Q2: What does an elevated RI indicate?
A: Elevated RI values may indicate increased vascular resistance, which can be associated with conditions such as renal disease, hypertension, or obstruction.

Q3: When should RI be measured in dogs?
A: RI measurement is indicated when assessing renal function, evaluating transplant organs, investigating hypertension, or monitoring vascular diseases.

Q4: Are there limitations to RI measurement?
A: RI can be affected by various factors including heart rate, blood pressure, hydration status, and technical aspects of the ultrasound examination.

Q5: How should the results be interpreted?
A: RI results should be interpreted in conjunction with clinical findings, other diagnostic tests, and by a qualified veterinary professional.