Can a CT (Computed Tomography) chest with contrast be done in a patient with a history of left nephrectomy (removal of the left kidney)?

CT Chest with Contrast in Patients with Left Nephrectomy

CT chest with contrast can be safely performed in patients with a history of left nephrectomy as long as the remaining kidney has adequate function to handle the contrast load.

Assessment of Renal Function

Before administering contrast for a chest CT in a patient with a single kidney, the following evaluation should be performed:

• Check renal function via serum creatinine and estimated glomerular filtration rate (eGFR)
• Review recent laboratory values for trends in renal function
• Assess for risk factors that may increase the likelihood of contrast-induced nephropathy

Decision Algorithm

1. If eGFR > 45 mL/min/1.73m²:

   • Proceed with contrast-enhanced CT chest
   • Ensure adequate hydration before and after the procedure

2. If eGFR 30-45 mL/min/1.73m²:

   • Consider risk vs. benefit of contrast administration
   • Implement nephroprotective measures:
     • IV hydration with normal saline before and after contrast
     • Minimize contrast volume
     • Avoid other nephrotoxic medications 24-48 hours before and after

3. If eGFR < 30 mL/min/1.73m²:

   • Consider non-contrast CT chest
   • Consider alternative imaging modalities (MRI chest if appropriate)
   • Nephrology consultation prior to contrast administration if contrast is deemed necessary

Clinical Context and Guidelines

According to the American College of Radiology guidelines, CT chest with contrast is considered appropriate for many clinical scenarios, including surveillance after treatment for renal cell carcinoma 1. The use of IV contrast for chest CT is optional but may be beneficial for detection and characterization of hilar lymph nodes 1.

The National Comprehensive Cancer Network (NCCN) guidelines indicate that chest imaging is an important component of follow-up after nephrectomy, with CT being preferred for patients with higher risk of recurrence 1. For post-nephrectomy surveillance, chest CT with contrast can be performed after IV contrast administration when patients are also undergoing abdominal imaging with contrast 1.

Special Considerations for Single-Kidney Patients

• Hydration: Ensure adequate hydration before and after contrast administration
• Contrast volume: Use the minimum necessary dose of contrast
• Timing: Consider spacing out contrast studies if multiple are needed
• Follow-up: Monitor renal function 48-72 hours after contrast administration

Common Pitfalls to Avoid

1. Failing to assess renal function: Always check recent creatinine/eGFR before administering contrast
2. Overlooking alternative imaging options: Non-contrast CT chest may be sufficient for some clinical scenarios
3. Ignoring hydration status: Dehydration increases risk of contrast-induced nephropathy
4. Disregarding medication interactions: Some medications (NSAIDs, certain antibiotics) may increase risk of renal injury when combined with contrast

Conclusion

Having a single kidney is not an absolute contraindication to contrast-enhanced CT chest. The decision should be based on the patient's current renal function, clinical necessity of the contrast study, and implementation of appropriate preventive measures to protect the remaining kidney function.