When ordering a breast MRI with contrast, should I assess kidney function, specifically estimated glomerular filtration rate (eGFR), in patients with liver disease?

When to Order eGFR Before Breast MRI with Contrast

For patients undergoing breast MRI with contrast, eGFR assessment is required for patients with hypertension, diabetes, kidney disease, but NOT routinely required for patients with liver disease alone. 1

Rationale for eGFR Assessment

Gadolinium-based contrast agents (GBCAs) used in breast MRI have different risk profiles based on their chemical structure. The primary concern with GBCAs is the risk of nephrogenic systemic fibrosis (NSF) in patients with impaired renal function.

Risk Stratification for eGFR Testing

According to the American College of Radiology and National Kidney Foundation consensus statements:

• Required eGFR testing before contrast administration:

  • Patients with known kidney disease (acute or chronic)
  • Patients with diabetes mellitus
  • Patients with hypertension requiring medical therapy
  • Patients on metformin/metformin-containing medications
  • Patients over 60 years of age
  • Patients with a history of renal surgery, single kidney, or renal cancer

• NOT required for eGFR testing:

  • Patients with liver disease alone (without other risk factors)
  • Patients under 60 years without other risk factors

GBCA Risk Categories and eGFR Considerations

GBCAs are classified into three groups based on NSF risk 1:

1. Group I (highest risk): Linear agents with highest NSF risk
2. Group II (very low risk): Macrocyclic agents with minimal NSF risk
3. Group III (likely very low risk): Agents with insufficient data

For Group II agents (which are commonly used):

• Kidney function screening is optional
• These agents can be safely used even in patients with eGFR <30 mL/min/1.73m²

For Group III agents:

• Kidney function screening is necessary
• Direct communication with referring provider is suggested for patients with eGFR <30 mL/min/1.73m²

Important Clinical Considerations

• Liver disease alone is not listed as an independent risk factor for contrast-induced nephropathy or NSF in any of the guidelines 1
• While liver disease can affect creatinine production and potentially impact eGFR measurements 2, this does not necessitate routine eGFR testing before contrast administration
• The risk of NSF increases with larger doses of Group I GBCAs, but is very low for standard doses of Group II GBCAs even in patients with severe renal impairment 1

Special Situations

• If the patient has both liver disease AND kidney disease, eGFR assessment is required
• If the patient has liver disease with abnormally high serum bilirubin (>3 mg/dL), reduced hepatic contrast enhancement may occur, but this is not related to kidney function 3

Practical Algorithm for eGFR Assessment Before Breast MRI

1. Always check eGFR if patient has:

   • Known kidney disease (any stage)
   • Diabetes mellitus
   • Hypertension requiring medication
   • Age >60 years
   • Taking metformin
   • History of renal surgery or single kidney

2. No need to check eGFR if patient has:

   • Liver disease without other risk factors
   • Age <60 years without other risk factors

3. If using Group II GBCA (preferred):

   • Can proceed with contrast even with eGFR <30 mL/min/1.73m²
   • Use lowest effective dose

Remember that the primary concern with GBCAs is NSF risk in patients with kidney dysfunction, not liver dysfunction. The guidelines do not support routine eGFR testing in patients with isolated liver disease.