From the Guidelines
For patients with end-stage renal disease (ESRD) who need an MRI to check for osteomyelitis, a non-contrast MRI is generally recommended. According to the American College of Radiology Appropriateness Criteria, MRI without IV contrast is usually appropriate as the next imaging study for suspected osteomyelitis following normal radiographs, or with findings suggestive of osteomyelitis 1. This approach is particularly relevant for ESRD patients, as gadolinium-based contrast agents used in MRI studies can pose risks, including nephrogenic systemic fibrosis (NSF), a rare but serious condition.
Some key points to consider when evaluating the need for contrast in MRI for osteomyelitis in ESRD patients include:
- Non-contrast MRI sequences such as T1-weighted, T2-weighted, and STIR images are usually sufficient to diagnose osteomyelitis, showing bone marrow edema, cortical destruction, and soft tissue changes.
- If contrast is absolutely necessary for diagnostic clarity, macrocyclic gadolinium agents at the lowest possible dose may be considered, followed by prompt hemodialysis after the procedure for patients already on dialysis.
- The decision should be made on a case-by-case basis, weighing the diagnostic benefits against potential risks, and should involve consultation between the radiologist, nephrologist, and referring physician.
Given the potential risks associated with contrast agents in ESRD patients and the equivalency of non-contrast and contrast-enhanced MRI for diagnosing osteomyelitis as stated in the ACR Appropriateness Criteria 1, a non-contrast MRI is the preferred initial approach for these patients.
From the Research
MRI for Osteomyelitis in ESRD Patients
- The use of MRI with or without contrast for diagnosing osteomyelitis in patients with End-Stage Renal Disease (ESRD) is a topic of interest due to the potential risks associated with gadolinium-based contrast agents 2, 3.
- A systematic review found that MRI with gadolinium-based contrast has a sensitivity of 89%, specificity of 79%, and overall diagnostic accuracy of 90% for diagnosing osteomyelitis in the appendicular skeleton, while MRI without contrast has a sensitivity of 92%, specificity of 89%, and overall diagnostic accuracy of 96% 4.
- Another study compared ferumoxytol with gadolinium as contrast agents for diagnosing osteomyelitis and found that ferumoxytol-induced MRI contrast changes correlated with systemic markers of inflammation, suggesting a potential alternative to gadolinium-based contrast agents 5.
Considerations for ESRD Patients
- Patients with ESRD are at increased risk of nephrogenic systemic fibrosis (NSF) when exposed to gadolinium-based contrast agents, and the use of these agents is not recommended in patients with reduced renal function 2, 3.
- Alternative imaging modalities should be considered in patients with ESRD, and if MRI with contrast is necessary, the use of the lowest dose possible of newer macrocylic, ionic agents (gadoterate meglumine) is recommended, along with immediate post-procedural hemodialysis (HD) in patients already on HD or peritoneal dialysis 3.
- The potential risks and benefits of using gadolinium-based contrast agents in ESRD patients should be carefully weighed, and alternative diagnostic approaches should be considered whenever possible 6.