Foot MRI Recognition Pattern

Systematic approach to interpreting foot MRI with anatomical landmarks, common pathologies, and protocol optimization

Enhance your radiology skills with our app!

Download Radiology Assistant App

1. MRI Protocol

A. Standard Sequences

• • T1-weighted:
  - Anatomical detail
  - Bone marrow evaluation
  - Slice thickness: 3-4mm
• • T2-weighted fat-sat:
  - Fluid-sensitive
  - Edema detection
  - STIR alternative
• • PD-weighted:
  - Cartilage/tendon detail
  - Intermediate TE

B. Specialized Sequences

• • DIXON:
  - Simultaneous water/fat imaging
  - Useful for metal artifact reduction
• • 3D isotropic:
  - SPACE/CUBE sequences
  - Reformats in any plane

2. Anatomical Evaluation

A. Compartment Approach

Compartment

Key Structures

Common Pathology

Medial

Abductor hallucis, posterior tibial tendon

Tibialis posterior tendinopathy

Lateral

Peroneal tendons, calcaneofibular ligament

Peroneal tendon subluxation

Central

Plantar fascia, flexor digitorum

Plantar fasciitis

B. Key Landmarks

• • Lisfranc joint:
  - Tarsometatarsal articulation
  - Assess for ligament disruption
• • Sinus tarsi:
  - Fat-filled space
  - Edema in sinus tarsi syndrome

3. Tendon Abnormalities

A. Common Tendinopathies

Tendon

Location

MRI Signs

Achilles

2-6cm above insertion

Thickening, intrasubstance signal

Posterior tibial

Medial malleolus

Tenosynovitis, longitudinal splits

Peroneal

Lateral malleolus

Subluxation, split tears

B. Tendon Rupture Grading

• • Grade 1:
  - Peritendinous edema
  - Normal tendon morphology
• • Grade 2:
  - Partial thickness tear
  - Fiber disruption <50%
• • Grade 3:
  - Complete rupture
  - Fiber discontinuity

4. Ligament Assessment

A. Key Ligaments

Ligament

Appearance

Injury Signs

Spring

Calcaneonavicular

Thickening, discontinuity

Lisfranc

Medial cuneiform-2nd MT

Avulsion, marrow edema

ATFL

Anterolateral ankle

Thickening, wavy fibers

5. Bone Marrow & Osteochondral

A. Marrow Abnormalities

• • Stress reaction:
  - T1: preserved fat signal
  - T2/STIR: edema
• • Fracture:
  - T1: hypointense line
  - T2: surrounding edema

B. Osteochondral Lesions

Stage

MRI Features

I

Subchondral edema, intact cartilage

II

Partial detachment

III

Complete detachment, nondisplaced

IV

Displaced fragment

6. Special Conditions

A. Diabetic Foot

• • Osteomyelitis:
  - Cortical disruption
  - Adjacent soft tissue ulcer
  - Diffuse marrow edema
• • Charcot:
  - Dislocation/fragmentation
  - Subchondral cysts

B. Nerve Entrapment

• • Tarsal tunnel:
  - Tibial nerve enlargement
  - Perineural fibrosis

7. Reporting Template

• 1. Technique: Sequences, planes
• 2. Tendons:
  - Achilles, peroneal, tibialis
  - Integrity, signal changes
• 3. Ligaments:
  - Lisfranc, spring
  - ATFL/CFL if included
• 4. Bones:
  - Marrow edema
  - Fracture lines
• 5. Soft tissues:
  - Plantar fascia
  - Masses/collections

Always correlate with clinical history and physical exam findings. For tendon assessment, use two orthogonal planes. In trauma cases, carefully evaluate the Lisfranc complex. For diabetic patients, differentiate osteomyelitis from neuroarthropathy. Document nerve abnormalities in patients with sensory symptoms. Compare with prior imaging when available to assess progression.

Get more radiology resources in our app!

Download Radiology Assistant App Now