1. What is Bladder Volume Calculation on Ultrasound?

Definition: This calculator estimates bladder volume using ultrasound measurements based on the ellipsoid formula.

Purpose: It helps medical professionals assess bladder volume non-invasively, useful for evaluating urinary retention or post-void residual volume.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( V \) — Volume of bladder (cm³)
• \( L \) — Length (cm)
• \( W \) — Width (cm)
• \( H \) — Height (cm)

Explanation: The formula approximates the bladder as an ellipsoid shape, which is the standard method for ultrasound bladder volume estimation.

3. Importance of Bladder Volume Measurement

Details: Accurate bladder volume measurement helps diagnose conditions like urinary retention, assess post-void residual, and evaluate bladder function.

4. Using the Calculator

Tips: Enter the three orthogonal measurements (length, width, height) obtained from ultrasound imaging in centimeters.

5. Frequently Asked Questions (FAQ)

Q1: How accurate is this method?
A: The ellipsoid method has about 90% accuracy compared to catheterized volumes, with slight overestimation in very full bladders.

Q2: What's a normal bladder volume?
A: Normal bladder capacity is typically 400-600 mL, but varies by age, sex, and individual factors.

Q3: How do I convert cm³ to mL?
A: 1 cm³ equals 1 mL, so no conversion is needed - the result can be read directly as milliliters.

Q4: When is this measurement most useful?
A: For evaluating urinary retention, post-void residuals, and bladder capacity in non-invasive urodynamics.

Q5: Are there alternative calculation methods?
A: Some ultrasound machines use different formulas (like the prolate ellipsoid method), but this is the most widely accepted standard.