1. What is Bladder Volume Calculation?

The bladder volume calculation estimates urine volume in the bladder using measurements from CT imaging. It's commonly used in urology to assess urinary retention, post-void residual volume, and bladder function.

2. How Does the Calculator Work?

The calculator uses the ellipsoid volume formula:

Where:

• \( Length \) — Longest dimension of bladder (cm)
• \( Width \) — Perpendicular to length (cm)
• \( Height \) — Anteroposterior dimension (cm)
• 0.52 — Correction factor for bladder shape

Explanation: The formula approximates bladder volume by treating it as an ellipsoid shape, with the correction factor accounting for the bladder's irregular form.

3. Importance of Bladder Volume Measurement

Details: Accurate bladder volume measurement is crucial for diagnosing urinary retention, evaluating bladder function, monitoring post-void residuals, and assessing the need for catheterization.

4. Using the Calculator

Tips: Enter measurements in centimeters from CT imaging. All values must be valid (greater than 0). For best results, measurements should be taken at maximal bladder distension.

5. Frequently Asked Questions (FAQ)

Q1: How accurate is this calculation compared to ultrasound?
A: The CT-based calculation is generally more accurate than ultrasound estimates, with correlation coefficients typically >0.9 when compared to catheterized volumes.

Q2: What is a normal bladder volume?
A: Normal bladder capacity is typically 300-500 mL in adults, though this varies with age, gender, and individual factors.

Q3: When is this calculation most useful?
A: Particularly valuable for assessing chronic urinary retention, neurogenic bladder, and post-operative bladder function.

Q4: Are there limitations to this method?
A: Less accurate with irregularly shaped bladders or when bladder walls are thickened. May overestimate volume in cases of significant trabeculation.

Q5: Can this be used for pediatric patients?
A: Yes, but normal volumes vary significantly with age in children. Pediatric-specific reference ranges should be used for interpretation.