From the Guidelines
For persistent internal gluteal (inferior gluteal) pain, MRI is the ideal imaging modality of choice. This recommendation is based on the fact that MRI provides excellent visualization of soft tissues, including muscles, tendons, ligaments, and nerves in the gluteal region, making it superior for diagnosing conditions like piriformis syndrome, hamstring tendinopathy, ischiofemoral impingement, and sciatic nerve entrapment 1.
Key Considerations for Imaging Modalities
- MRI is highly sensitive and specific for detecting many abnormalities involving the surrounding soft tissues and should, in general, be the first imaging technique used after radiographs 1.
- The study should be performed with contrast if inflammatory or infectious processes are suspected, as it can aid in the evaluation of soft tissues and enhance the imaging contrast between vascular and nonvascular tissues 1.
- Before proceeding to MRI, plain radiographs of the pelvis and hip may be useful as an initial screening tool to rule out bony abnormalities or arthritis 1.
- Ultrasound can be considered as a less expensive alternative that allows dynamic assessment but has limitations in deeper tissue visualization 1.
- CT scans are generally reserved for cases where bony pathology is the primary concern 1.
Special Considerations for Specific Conditions
- For evaluating labral tears, MRI with or without arthrography can be used, and direct MR arthrography with the intra-articular injection of a dilute solution of gadolinium chelate in saline has been established as a reliable technique for diagnosing acetabular labral tears 1.
- Ultrastructural cartilage imaging may prove to be useful to determine potential timing of surgery or whether surgery would be appropriate for femoral acetabular impingement (FAI) 1.
- Diagnostic joint injections are safe and useful tools for confirming the etiology of pain, such as labral tear, and US can also be used to localize paralabral cysts for aspiration and injection 1.
When ordering an MRI for gluteal pain, it is essential to specify the clinical history and suspected diagnosis to ensure appropriate protocols are used, as specialized sequences may be needed to properly evaluate specific structures like the sciatic nerve or piriformis muscle 1. Patients should be advised that the procedure takes approximately 30-45 minutes and requires lying still in a confined space.
From the Research
Ideal Imaging Modality for Persistent Internal Gluteal Pain
The ideal imaging modality for persistent internal gluteal (inferior gluteal) pain is a subject of discussion in various studies.
- Magnetic Resonance Imaging (MRI) is considered the diagnostic procedure of choice for assessing Deep Gluteal Syndrome (DGS) and may substantially influence the management of these patients 2.
- MRI is also useful in diagnosing gluteal muscle tears or strains, as it can show partial tears and fluid infiltration due to edema and hemorrhage 3.
- Ultrasound (US) can also be used for diagnosing muscle tears or strains, and is recommended for accurate diagnosis of muscle tear or strain 3.
- US-guided infiltration of the perisciatic nerve is a simple and effective technique for treating piriformis syndrome, using the inferior gluteal artery as a landmark 4.
- Imaging findings for pelvic neural causes of chronic buttock pain and sciatica primarily relate to the presence of sciatic neuritis and peri-sciatic pathology, including neural compression and peri-neural adhesions or fibrosis, and can be evaluated using MRI and US 5.
Key Imaging Modalities
- MRI: considered the diagnostic procedure of choice for assessing DGS and useful in diagnosing gluteal muscle tears or strains 2, 3.
- US: useful in diagnosing muscle tears or strains and can be used for US-guided infiltration of the perisciatic nerve 3, 4.
- MRI and US: used to evaluate imaging findings for pelvic neural causes of chronic buttock pain and sciatica 5.