When should a wrist MRI be ordered for a patient with a soft‑tissue injury who has persistent pain, swelling, or functional limitation after 7‑10 days of rest, splinting, NSAIDs, and a normal plain radiograph, especially if there is suspicion of ligamentous tear, occult fracture, high‑energy mechanism, or risk factors such as advanced age, diabetes, or chronic steroid use?

When to Order MRI After Soft Tissue Wrist Injury

Order wrist MRI at 10-14 days after injury if pain, swelling, or functional limitation persists despite conservative management (rest, splinting, NSAIDs) and initial radiographs are negative or equivocal. 1

Timing Algorithm for MRI Ordering

Immediate to 10-14 Days Post-Injury

• Initial imaging: Obtain standard 3-view radiographs (posteroanterior, lateral, and 45° semipronated oblique) at presentation for all acute wrist trauma 1
• Conservative management trial: Implement rest, splinting, NSAIDs for 7-10 days if radiographs are negative 1
• Repeat radiographs at 10-14 days: This is an equivalent alternative to immediate MRI and may reveal fractures that were initially occult 1

When to Proceed Directly to MRI (Without Waiting 10-14 Days)

Order MRI earlier if any of the following high-risk features are present:

• High-energy mechanism of injury with persistent severe pain despite negative radiographs 2
• Clinical suspicion of ligamentous injury: Specific point tenderness over scapholunate or lunotriquetral ligaments, positive Watson test, or midcarpal clunk 1
• Suspected triangular fibrocartilage complex (TFCC) tear: Ulnar-sided wrist pain with clicking or instability 1
• Suspected occult scaphoid fracture: Anatomic snuffbox tenderness with negative radiographs, as 80% of MRIs done within 4 days post-injury reveal pathology 2
• Risk factors for poor healing: Advanced age, diabetes, chronic steroid use, or smoking 2

What MRI Detects That Radiographs Miss

In patients with negative radiographs after acute wrist trauma, MRI reveals pathology in 80% of cases 2:

• Occult fractures: 54 fractures detected in 155 patients with normal radiographs, most commonly in radius, scaphoid, triquetrum, capitate, and lunate 2
• Bone bruises/contusions: 56 bone bruises identified, which may progress to fracture or avascular necrosis if not protected 2
• Soft tissue injuries: 73 soft tissue injuries including 15 TFCC tears and 5 scapholunate ligament lesions 2
• Median of 2 pathological findings per patient (range 0-8), indicating multiple concurrent injuries are common 2

MRI Protocol Selection

Standard MRI Without IV Contrast

• First-line choice for suspected occult fracture, bone bruise, ligament tear, or tendon injury 1
• Sensitivity for ligament tears at 3.0T: Scapholunate 70-87%, lunotriquetral 50-63%, TFCC 63-100% 1
• No IV contrast needed for bone marrow edema, fractures, or most soft tissue injuries 1

MR Arthrography

• Superior to standard MRI for intrinsic ligament tears (scapholunate, lunotriquetral) and TFCC injuries 1
• Sensitivity with radiocarpal injection: 63-100% for TFCC tears, intrinsic ligament injuries, and cartilage lesions 1
• Consider for surgical planning when operative intervention is likely based on clinical examination 1
• Add DRUJ injection if ulnar-sided TFCC detachment is suspected 1

MRI With IV Contrast

• Reserve for suspected infection: Septic arthritis, tenosynovitis, or soft tissue abscess 1
• Inflammatory arthropathy: Distinguishes synovitis from joint effusion/ganglion cysts in suspected rheumatoid arthritis or seronegative spondyloarthropathy 1
• Not routinely indicated for traumatic injuries 1

Alternative Imaging Modalities

CT Without IV Contrast

• Equivalent alternative to MRI at 10-14 days for suspected occult fracture 1
• Preferred over MRI for suspected hook of hamate fracture due to superior cortical bone detail 1
• Advantages: Shorter acquisition time, easier in casted patients, better for claustrophobic patients 1
• Disadvantages: Lower sensitivity for bone bruises and soft tissue injuries compared to MRI 1

Ultrasound

• Equivalent to MRI for suspected tendon injuries (flexor/extensor tendons) and occult ganglion cysts 1
• Advantages: Real-time dynamic assessment, lower cost, no contraindications 1
• Limitations: Operator-dependent, poor visualization of intrinsic ligaments and bone marrow 1

Clinical Impact of Early MRI

• Changes management in 69.5% of cases when obtained for chronic wrist pain 1
• Leads to more differentiated treatment in >33% of acute wrist sprains when MRI reveals specific pathology 2
• Prevents inappropriate treatment by identifying injuries that require immobilization, surgical referral, or specific rehabilitation 2
• Reassures patients when MRI is normal (20% of cases), avoiding unnecessary prolonged immobilization 1, 2

Common Pitfalls to Avoid

• Inadequate initial radiographs: Two-view examination misses fractures; always obtain minimum 3 views 1, 3
• Delaying MRI beyond 2 weeks: Persistent pain after 10-14 days of conservative management warrants MRI rather than continued observation 1, 2
• Assuming "wrist sprain" is benign: This diagnosis is inaccurate—80% have identifiable pathology on MRI that requires specific treatment 2
• Ordering MRI with contrast for trauma: IV contrast adds no value for acute traumatic injuries unless infection is suspected 1
• Missing soft tissue swelling on radiographs: Navicular fat pad swelling strongly suggests scaphoid fracture; dorsal wrist fat plane swelling indicates carpal fracture or dislocation 4
• Failing to protect the wrist while awaiting imaging: Immobilize with splint to prevent progression of bone bruises to complete fractures 2

Specific High-Risk Scenarios Requiring Earlier MRI

• Scaphoid tenderness with negative radiographs: MRI within 3-5 days prevents delayed diagnosis of scaphoid fracture, which has high risk of avascular necrosis and nonunion 1, 2
• Distal radioulnar joint instability: MRI or CT in neutral, supinated, and pronated positions to assess for TFCC tear and DRUJ subluxation 1
• Suspected Kienböck disease: MRI detects early avascular necrosis of lunate before radiographic changes appear 1, 5
• Ulnar impaction syndrome: MRI shows characteristic focal signal changes in ulnar aspect of lunate 5