# AI miscalculates contrast volume for CT scan based on wrong formula, exceeding safe iodine dose for renal impairment

- **ID:** `medical/ct-contrast-renal-dose-miscalculation`
- **Domain:** medical
- **Category:** data_error
- **Error Code:** `CT-CONTRAST-VOL-ERR`
- **Verification:** ai_generated
- **Fix Rate:** 85%

## Root Cause

Contrast volume should be calculated using patient weight and estimated GFR (e.g., 1.5 mL/kg for eGFR > 60, max 125 mL), but AI applies a fixed volume (e.g., 100 mL for all adults) or uses body surface area formula, leading to potential contrast-induced nephropathy (CIN) in at-risk patients.

## Version Compatibility

| Version | Status | Introduced | Deprecated |
|---------|--------|------------|------------|
| Siemens Somatom Definition Flash v7.0 | active | — | — |
| GE Revolution CT v3.2 | active | — | — |
| Canon Aquilion ONE v6.5 | active | — | — |

## Workarounds

1. **Use the ACR contrast manual formula: for eGFR > 60, give 1.5 mL/kg up to 125 mL; for eGFR 30-60, give 1.0 mL/kg up to 100 mL; for eGFR < 30, consult radiologist for alternative imaging or pre-hydration protocol** (85% success)
   ```
   Use the ACR contrast manual formula: for eGFR > 60, give 1.5 mL/kg up to 125 mL; for eGFR 30-60, give 1.0 mL/kg up to 100 mL; for eGFR < 30, consult radiologist for alternative imaging or pre-hydration protocol
   ```
2. **Implement a clinical decision support tool (e.g., Nuance mPower) that checks eGFR, weight, and contrast type before approving the scan order** (90% success)
   ```
   Implement a clinical decision support tool (e.g., Nuance mPower) that checks eGFR, weight, and contrast type before approving the scan order
   ```
3. **Use iso-osmolar contrast (iodixanol) for all patients with eGFR < 45, which reduces CIN risk, and calculate volume based on 1.0 mL/kg max 100 mL** (80% success)
   ```
   Use iso-osmolar contrast (iodixanol) for all patients with eGFR < 45, which reduces CIN risk, and calculate volume based on 1.0 mL/kg max 100 mL
   ```

## Dead Ends

- **** — This is safe only for normal renal function; for eGFR < 30, even 1.0 mL/kg can exceed safe iodine load (e.g., 350 mgI/kg) (50% fail)
- **** — Age alone is not a reliable predictor; some elderly have normal eGFR and need full dose for diagnostic quality; under-dosing causes nondiagnostic scans (65% fail)
- **** — AI may use outdated formulas (e.g., Cockcroft-Gault instead of CKD-EPI) or ignore acute kidney injury, giving falsely normal eGFR (55% fail)