From the Guidelines
You can get an MRI with contrast after receiving a CT scan with contrast, as there are no additional safety concerns with performing these procedures immediately before or after each other. According to the American College of Radiology and the National Kidney Foundation, contrast-enhanced MRI may be performed immediately before or after contrast-enhanced CT (and vice versa) without altering the recommendations for patients receiving nephrotoxic medications, chemotherapy, or contrast-enhanced CT 1. Some key points to consider include:
- Residual interstitial, urinary tract, or vascular gadolinium-based contrast media (GBCM) from the MRI may mildly alter the appearance of normal and pathologic structures at CT, but this will not affect the diagnostic value of CT for almost all clinical indications 1.
- Nephrotoxic drugs do not need to be withheld prior to an on-label dose of group II or group III GBCM, which are commonly used in MRI contrast agents 1.
- It is essential to note that your healthcare provider may still check your kidney function beforehand with blood tests like creatinine levels to ensure your kidneys can handle the additional contrast load, especially if both scans are urgently needed.
- Staying well-hydrated before and after both procedures helps your body clear the contrast agents more efficiently and reduces the risk of kidney problems.
From the FDA Drug Label
The studies were designed to compare MultiHance contrast MRI to non-contrast MRI alone. In Study A, patients highly suspected of having a lesion(s) of the CNS based on nuclear medicine imaging, computed tomography (CT), contrast CT, MRI, contrast- MRI, or angiography were randomized to receive two MRI evaluations with 0.05 mmol/kg (n=140) or 0. 1 mmol/kg (n=136) of MultiHance.
The FDA drug label does not answer the question.
From the Research
General Considerations
- It is possible to get a Magnetic Resonance Imaging (MRI) with contrast after receiving a Computed Tomography (CT) scan with contrast, but there are certain considerations to keep in mind 2, 3, 4.
- The main concern is the potential risk of contrast-induced nephropathy (CIN) or nephrogenic systemic fibrosis (NSF) associated with the use of iodinated CT and gadolinium-based MRI contrast media 2, 5, 6.
Safety of Contrast Agents
- Studies have shown that the use of gadolinium-based contrast agents in MRI is generally safe, even in patients with severe kidney disease 5.
- However, the risk of CIN and NSF should not be ignored, especially in patients with low estimated glomerular filtration rate (eGFR) 2, 6.
- The pharmacokinetics of contrast media will determine how long safe waiting intervals between successive CT or MRI examinations should be 3.
Waiting Times Between Examinations
- The Contrast Media Safety Committee suggests a waiting time between elective contrast-enhanced CT and MRI examinations of optimally 12 hours and minimally 4 hours in patients with normal renal function (eGFR > 60 mL/min/1.73 m2) 3.
- Safe waiting times increase with increasing renal insufficiency 3.
- An animal study found that conducting contrast-enhanced MRI on the same day as contrast-enhanced CT may not induce clinically significant kidney injury, but a sufficient time interval, probably more than 24 hours, between repeated contrast-enhanced CT examinations may be necessary to avoid deterioration in renal function 4.
Alternative Imaging Modalities
- Contrast-enhanced ultrasound (CEUS) is considered an effective first-line imaging modality for post-operative early and long-term follow-up in renal transplant patients, reducing the need for biopsies and providing adequate guidance for drainage procedures 6.
- CEUS may be a viable alternative to CT and MRI in certain situations, especially in patients with contraindications to iodine-based or gadolinium-based contrast agents 6.