Resources/Protocols
Musculoskeletal MRI protocols
Small fields of view, high resolution, and coil craft — the region that teaches SNR trade-offs faster than any other.
Musculoskeletal imaging is where parameter decisions become visible immediately. Push resolution too far and noise swamps the cartilage; suppress fat carelessly and a tendon tear disappears. Every MSK protocol is a negotiation between resolution, signal and scan time, decided per joint.
Deep-dive protocol guides
Full step-by-step protocols — positioning, per-sequence planning, parameters, artifacts and a review checklist for each study:
Studies in this region
- Shoulder
- Axilla
- Arm
- Elbow
- Wrist
- Hand
- Thumb & fingers
- Hip
- Thigh
- Knee
- Lower leg
- Ankle
- Foot
- Ankle with foot
- MR arthrography
- MR neurography
- Limb angiography
Planning
- Choose the smallest coil that comfortably covers the joint — coil proximity buys signal that no parameter change can replace.
- Position the joint at the coil centre and, where the protocol expects it, in the standard orientation for that examination.
- Plan all three planes from the joint's own anatomy, not the scanner axes.
- Keep the field of view tight and raise the matrix — MSK diagnosis depends on resolving millimetre structures.
- Immobilise with padding: a small joint moving slightly ruins a high-resolution sequence faster than a large one.
Sequences by study
| Study | Typical core | Why |
|---|---|---|
| Shoulder | Oblique coronal & sagittal PD/T2 fat-sat, axial T2 | Rotator cuff and labral assessment |
| Knee | Sagittal PD fat-sat, coronal T1/PD, axial T2 fat-sat | Meniscus, ligaments, cartilage |
| Wrist / hand | Thin coronal T1 & PD fat-sat, axial T2 | Small structures need small voxels |
| Ankle / foot | Axial, coronal and sagittal PD fat-sat with T1 | Tendon and ligament tracking in three planes |
| Hip | Coronal STIR & T1, axial and oblique sequences | Marrow, labrum and joint effusion |
| MR arthrography | Fat-suppressed T1 in multiple planes after joint injection | Contrast distends the joint and outlines labral or cartilage tears |
| MR neurography | High-resolution fat-suppressed T2 along the nerve course | Nerve signal and calibre change |
Mistakes that cost repeats
- Field of view larger than the joint, wasting resolution on soft tissue nobody is assessing.
- Fat suppression failing off-centre — reposition the joint towards isocentre rather than accepting patchy suppression.
- Planning from scanner axes instead of joint anatomy, producing planes that no orthopedic reader recognises.
- Uncomfortable positioning: an unsupported limb will move, and high-resolution sequences show it first.
Common questions
- Why does coil choice matter so much in MSK MRI?
- Signal falls off rapidly with distance from the coil. A correctly sized joint coil placed close to the anatomy provides signal that no combination of TR, TE or averaging can recover from a large, distant coil.
- Why is fat suppression used in most MSK sequences?
- Marrow and soft-tissue fat are bright on PD and T2 imaging and can hide edema, tears and fluid. Suppressing fat makes pathological fluid stand out clearly against a dark background.
- What does MR arthrography add?
- Injected contrast distends the joint and pushes into tears that would otherwise stay collapsed and invisible, making labral and cartilage lesions far easier to identify.
- Why do small joints need thinner slices?
- Partial volume averaging. A 4 mm slice through a 2 mm ligament blends the structure with surrounding tissue; thin slices keep small anatomy distinct.
Try it in ScanFlo: Scan a knee with a standard field of view, then repeat with the field of view reduced and matrix raised for the same scan time. Compare meniscal detail against noise — the trade-off you just made is the core MSK skill.