From the Guidelines
Yes, you can order a CT scan without contrast for a patient with impaired renal function undergoing dialysis. Non-contrast CT scans are generally safe for patients with renal impairment as they don't involve the administration of iodinated contrast media that could potentially worsen kidney function 1. For dialysis patients specifically, the timing of the scan in relation to dialysis sessions isn't critical when contrast isn't being used.
Key Considerations
- Non-contrast CT scans do not pose the risk of contrast-induced nephropathy, making them a safer option for patients with impaired renal function 1.
- Patients on regular dialysis can receive contrast if diagnostic needs require it, but the scan should ideally be scheduled so that dialysis follows shortly after the contrast administration (within 24 hours) to remove the contrast from circulation 1.
- The primary concern with contrast in renal patients is the risk of further damaging already compromised kidneys, but this risk is less relevant for patients already on dialysis since their kidneys are non-functional 1.
Additional Information
- Ultrasound (US) contrast media are not nephrotoxic and can be used for microvascular imaging in patients with acute kidney injury (AKI) or chronic kidney disease (CKD) 1.
- Contrast-enhanced US has the potential to provide dynamic quantitative information about renal perfusion and can diagnose acute cortical necrosis and infarction in allografts and native kidneys 1.
- For MRI, there are risk-benefit considerations with respect to the type of gadolinium-based contrast agents, and unenhanced MR angiography (MRA) techniques may be diagnostic 1.
From the Research
CT Scan without Contrast for Patients with Impaired Renal Function Undergoing Dialysis
- The use of contrast agents in patients with impaired renal function, particularly those undergoing dialysis, requires careful consideration due to the risk of contrast-induced nephropathy (CIN) 2, 3.
- Studies have shown that the risk of CIN is debatable and may be lower than previously thought, especially with the use of low-osmolar or iso-osmolar contrast media 4.
- However, patients with severely decreased kidney function, such as those on dialysis, are still at risk of CIN and other complications 5, 6.
- The incidence of CIN after contrast-enhanced CT in patients with chronic kidney disease (CKD) has been reported to be around 2.5% 6.
- The risk of CIN is increased in patients with severely decreased kidney function and diabetes 6.
- Alternative imaging modalities, such as non-contrast CT or MRI without gadolinium-based contrast agents, may be considered for patients with impaired renal function undergoing dialysis 2.
- If a CT scan without contrast is ordered for a patient with impaired renal function undergoing dialysis, it is essential to weigh the benefits and risks of the procedure and to consider alternative imaging modalities 2, 3.