1. What is Bladder Volume Measurement on Ultrasound?

Definition: This calculator estimates bladder volume using ultrasound measurements by modeling the bladder as an ellipsoid shape.

Purpose: It helps medical professionals assess bladder capacity, detect urinary retention, and evaluate bladder function.

2. How Does the Calculator Work?

The calculator uses the ellipsoid volume formula:

Where:

• \( V \) — Volume of bladder (cm³)
• \( L \) — Maximum length (cm)
• \( W \) — Maximum width (cm)
• \( H \) — Maximum height (cm)

Explanation: The formula approximates bladder volume by treating it as a three-dimensional ellipsoid, with π/6 (approximately 0.52) as the shape factor.

3. Importance of Bladder Volume Measurement

Details: Accurate bladder volume assessment helps diagnose conditions like urinary retention, monitor bladder function, and guide catheterization decisions.

4. Using the Calculator

Tips: Enter the maximum length, width, and height measurements obtained from bladder ultrasound in centimeters. All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: How accurate is this method?
A: The ellipsoid method is about 85-90% accurate compared to actual bladder volumes, with tendency to underestimate larger volumes.

Q2: What's a normal bladder volume?
A: Normal bladder capacity is typically 300-500 mL (300-500 cm³) in adults, but varies with age, gender, and individual factors.

Q3: When is this measurement clinically important?
A: Important for evaluating urinary retention, post-void residual volume, and bladder dysfunction in various urological conditions.

Q4: How do I convert cm³ to mL?
A: 1 cm³ equals 1 mL, so no conversion is needed - the values are equivalent.

Q5: Are there alternative calculation methods?
A: Yes, some ultrasound machines use different formulas (like the prolate ellipsoid method) or automated volume calculation tools.