MR Arthrogram — hip
Hip joint, acetabular labrum, capsule and proximal femur, including radial reformats around the femoral neck axis.
Typical, not policy
Timings, volumes and delays here are representative values drawn from published guidance. Scanner generation, injector, cardiac output and local preference all move them. Confirm against your department's own protocol before you rely on a number.
When to use it
- Suspected acetabular labral tear in femoroacetabular impingement where arthroscopy is being considered.
- Assessment of chondral delamination alongside labral pathology.
- Persistent groin pain after a non-diagnostic conventional hip MRI.
- Assessment of the post-operative hip labrum.
- Where an intra-articular anaesthetic challenge is wanted to confirm the joint as the pain source.
Technique
- Fluoroscopic or ultrasound-guided injection with sterile technique, then immediate transfer to the scanner.
- Fat-suppressed T1 in coronal, sagittal and oblique-axial planes, plus radial sequences perpendicular to the labrum around the femoral neck axis.
- A large field-of-view coronal fluid-sensitive sequence of the pelvis is retained to detect extra-articular causes.
- Reported injection volumes for the hip vary from roughly 10 to 20 mL, with around 15 mL commonly used.
Where it goes wrong
- No radial imaging, so anterosuperior labral tears are under-detected — the exact reason the arthrogram was requested.
- Under-distension from too small an injected volume, or capsular leak in a patient with previous surgery.
- Long injection-to-scan interval.
- Anaesthetic response not recorded, discarding useful diagnostic information that the procedure generated for free.
Clinical questions that reach this study
Contrast
Gadolinium, intra-articular
Intra-articular dilute gadolinium at approximately 1:200 dilution, typically 10-20 mL for the hip joint, often with iodinated contrast for fluoroscopic confirmation and a short-acting local anaesthetic.
- An intra-articular anaesthetic response is diagnostically useful in its own right and should be documented.
Acquisition
- Breathing
- Free breathing.
- Preparation
- Consent, coagulation status and infection screening are needed as for any joint injection; anticoagulation should be declared at vetting. The injection and the MRI must be scheduled together — image quality falls once the contrast begins to be absorbed and diluted. Gadolinium here is intra-articular, not intravenous, and is used in a very small total dose; the renal considerations of an IV study do not transfer directly.
Safety checks this protocol carries
Derived from the contrast agent and phases above, not authored here — which is why they cannot drift apart from what the protocol actually does.
- MR safety screening for implants and foreign bodies· radiographer at scan