From the Guidelines
For an ankle injury, an MRI ankle without IV contrast is usually the recommended imaging study, as it provides detailed images of soft tissues, including ligaments, tendons, cartilage, and bone marrow, making it excellent for diagnosing common ankle injuries such as ligament tears, tendon injuries, osteochondral lesions, and stress fractures 1.
Key Considerations
- The choice of MRI protocol depends on the specific injury being evaluated, with the possibility of using 1.5T or 3T MRI strength, depending on availability and the need for higher resolution images for subtle cartilage injuries.
- In some cases, such as suspected infection, inflammatory arthritis, or tumors, an MRI with contrast (gadolinium) might be ordered 1.
- The American College of Radiology recommends MRI ankle without IV contrast or CT ankle without IV contrast for patients with acute trauma to the ankle and persistent pain for more than 1 week but less than 3 weeks, with negative initial radiographs and no exclusionary criteria present 1.
Imaging Options
- MRI ankle without IV contrast is more likely to be performed for potential osteochondral injury evaluation, while CT ankle without IV contrast is more likely to be performed for known fracture evaluation 1.
- MRI is the reference standard for ligamentous injury and assessment of stability, which is particularly important in athletes 1.
Patient Preparation
- No special preparation is needed for an MRI ankle without IV contrast, though metal objects must be removed before entering the MRI room.
- Patients will need to remain still during the scan, which usually takes about 30-45 minutes to complete.
Clinical Decision Making
- The decision to order an MRI ankle without IV contrast should be based on the patient's specific symptoms, physical examination findings, and suspected diagnosis, as determined by the doctor 1.
From the Research
Ankle Injury MRI Types
- For ankle injuries, MRI is the established noninvasive means of evaluation 2
- The design of an ankle protocol depends on various factors, including magnetic field strength, imaging planes, and the presence of metal prostheses 2
- Ultrashort echo time sequences are valuable for both structural and quantitative evaluation of ankle injuries 2
- Specialized imaging planes, such as MR neurography, can be useful but may require metal reduction techniques and prolong acquisition times 2
Quantitative MRI Parameters
- Quantitative MRI techniques, such as T1, T2, T2*, T1rho, and diffusion-weighted imaging, can provide numerical values for tissue characterization 3
- These techniques can be used to evaluate various body imaging applications, including ankle injuries 3
- However, the application of these techniques for ankle injuries is not specifically discussed in the provided studies
MRI Sequences
- Turbo spin-echo (TSE) sequences can be used for routine MRI of various body parts, including the brain 4
- TSE sequences offer advantages such as reduced flow artifacts, better lesion contrast, and acquisition time reduction 4
- However, the use of TSE sequences for ankle injuries is not specifically discussed in the provided studies, and their application may vary depending on the specific clinical indications and protocol design 2