BladderVoidingEfficiencyAnalyzer

Utility description: Bladder Voiding Efficiency Analyzer

Bladder Voiding Efficiency Analyzer — Bladder emptying efficiency analysis tool

ℹ️  Utility calculates the percentage of activity evacuation from the bladder:
    • Voiding efficiency (normal >90%)
    • Residual activity percent (normal <10%)
    • Correction for background and Tc-99m radioactive decay

⚠️  CRITICAL: Low efficiency (<80%) may indicate pathology!
    Residual activity creates artifacts on kidneys and increases radiation dose.
    Important for differential diagnosis of obstructions and refluxes.

Usage:
  BladderVoidingEfficiencyAnalyzer.exe                            → demo mode (console output)
  BladderVoidingEfficiencyAnalyzer.exe input.csv output.json      → evaluate your data

Input format:
PatientID,StudyDate,PreVoidCounts,PostVoidCounts,BackgroundCounts,AcquisitionTimePreSec,AcquisitionTimePostSec,DecayCorrectionFactor,ResidualVolumeML

Example:
  PAT-RENAL-001,2026-07-21,150000,15000,500,60,60,1.05,20.0

— WHY IS THIS NEEDED?
During dynamic renography (with Tc-99m MAG3 or DTPA), the bladder accumulates radioactive urine.
Complete emptying is critical for:
• Accurate assessment of kidney function (to prevent bladder activity from "shining through" to the pelvis)
• Detection of vesicoureteral reflux (VUR)
• Diagnosis of neurogenic bladder or bladder neck obstruction
• Reducing patient radiation dose (residual urine continues to irradiate tissues)

⚠️  CRITICAL:
• Voiding efficiency >90% — normal for a healthy adult.
• Residual activity <10% — ensures no significant artifacts.
• Decay correction — mandatory if more than 5-10 minutes passed between "pre" and "post" frames.
• Background correction — necessary to account for scattered radiation from surrounding tissues.

Key features:
• Automatic calculation of Net Counts with background subtraction.
• Consideration of Tc-99m radioactive decay (T½=6h) between measurements.
• Calculation of Residual Activity Percent.
• Integration with residual urine volume data (if available).
• Generation of warnings for suspected pathological urine retention.

Critical parameters:
• Voiding efficiency: >90.0%
• Residual activity: <10.0%
• Net pre-void counts: >0
• Decay factor: 1.0–1.5 (typical range for short intervals)

💡 Usage tips:
1. Bladder ROI (Region of Interest) must be identical on "pre" and "post" frames.
2. Background is measured in an area near the bladder but outside the projection of kidneys and intestines.
3. Patient should drink water before the study to ensure sufficient diuresis.
4. If efficiency is low (<80%), repeat scanning after catheterization or ultrasound measurement of residual volume is recommended.
5. In children, normal efficiency may be lower due to incomplete sphincter control.

⚠️ Note: Accumulation of Tc-99m in the bladder is not a side effect but an expected excretion pathway. However, the inability to completely empty the bladder is a serious clinical sign. This utility helps quantify this parameter, converting visual assessment into precise numbers for the medical record.