Is an MRI with or without contrast recommended for a finger injury?

MRI for Finger Injury: Without Contrast is the Standard Approach

For most finger injuries, MRI without IV contrast is the appropriate imaging modality and provides excellent diagnostic accuracy for tendon, ligament, and bone injuries without the need for contrast administration. 1

When to Use MRI Without Contrast

MRI without IV contrast is ideal for evaluating the full spectrum of finger injuries and should be your default choice in the following scenarios:

Tendon Injuries

• MRI without contrast has excellent sensitivity (92-100%) and specificity (91-100%) for flexor tendon injuries, including jersey finger (flexor digitorum profundus avulsion) and assessment of tendon retraction level 1
• Extensor tendon injuries, including mallet finger and central slip injuries, are well-visualized without contrast, though sensitivity ranges from 28-85% for extensor hood injuries 1
• Pulley system injuries (particularly A2 and A4 pulleys) can be accurately depicted with 100% direct identification rates on non-contrast MRI 1

Ligament Injuries

• Collateral ligament tears show sensitivity of 67-100% and specificity of 91-94% on non-contrast MRI, including the critical Stener lesion of the thumb ulnar collateral ligament 1
• Volar plate injuries are accurately diagnosed without contrast, which is important since untreated lesions lead to contractures or joint laxity 1

Technical Considerations

• High-resolution 3T MRI with dedicated hand-and-wrist coils provides exquisite anatomic detail of finger structures 2, 3
• Normal ligaments and tendons show uniform low signal intensity, while disruption manifests as increased signal intensity, discontinuity, and heterogeneous signal 4, 5

When to Add IV Contrast

MRI with IV contrast is reserved for specific clinical scenarios and is NOT routinely needed for traumatic finger injuries:

Infectious/Inflammatory Conditions

• Suspected septic arthritis or soft tissue infection requires contrast to distinguish abscess from cellulitis 1
• Tenosynovitis evaluation benefits from contrast to differentiate active inflammation from simple fluid 1
• Rheumatoid arthritis or seronegative spondyloarthropathy evaluation requires contrast to distinguish synovitis from joint effusion and ganglion cysts 1

When to Consider MR Arthrography

MR arthrography (direct intra-articular gadolinium injection) is superior to standard MRI for specific wrist ligament injuries but has limited application in finger injuries:

• For metacarpophalangeal joint collateral ligament injuries, MR arthrography increases sensitivity from 67% to 75% and specificity from 91% to 98% 1
• However, this is a minimally invasive procedure and should be reserved for equivocal cases or surgical planning 1

Practical Algorithm for Finger Injury Imaging

1. Start with 3-view radiographs (PA, lateral, oblique) to assess for fractures and joint alignment 6

2. If radiographs are negative but clinical suspicion remains high:

   • Order MRI without IV contrast for suspected tendon, ligament, or occult fracture 1, 6
   • Alternative: Splint and repeat radiographs in 10-14 days 6

3. Add IV contrast only if:

   • Suspected infection (septic arthritis, abscess, osteomyelitis) 1
   • Inflammatory arthropathy evaluation 1
   • Need to distinguish tenosynovitis from simple effusion 1

4. Consider MR arthrography only for:

   • Equivocal collateral ligament injuries requiring definitive diagnosis before surgery 1

Common Pitfalls to Avoid

• Do not routinely order contrast for traumatic finger injuries – it adds cost, time, and IV access without improving diagnostic accuracy for tendons and ligaments 1
• Ensure adequate radiographs first (minimum 3 views) before proceeding to MRI, as many fractures are missed with only 2 views 6
• CT has limited utility for soft tissue finger injuries and should not be substituted for MRI 1
• Ultrasound has limited utility for bone and deep soft tissue injuries in fingers 6