MRI of the elbow (an approach)

MRI of the elbow is a fairly frequent examination in musculoskeletal radiology practice and not quite as common in general radiological practice. This approach is an example of how to create a radiological report of an elbow MRI with coverage of the most common anatomical sites of possible pathology, within the elbow without claim for completeness.

Systematic review

A systematic review in the MRI of the elbow is essential since elbow anatomy, pathologies and injury patterns and are rather complex and only rarely lead to an abnormality of a single structure but rather show diverse findings which might need to be addressed in further patient management.

Bones

The bony structures of the elbow, the pictured distal humerus with the trochlea, capitellum and the two epicondyles, the radial head and the proximal ulna with the olecranon are assessed:

• fractures
• bone tumors

Joint space and joint capsule

• assessment of the following structures:
  • joint space, joint effusion if present and possible intra-articular fragments or loose bodies
• synovia
  • synovial thickening and hyperenhancement and other abnormalities
  • elbow synovial fold syndrome

Ulnohumeral articulation

Assessment of the following structures:

• ulnohumeral articular cartilage and subchondral bony structures
  • chondral and osteochondral injury, subchondral fractures and subchondral cysts and or osteoarthritic changes of the trochlea and olecranon
• posterior compartment
  • subchondral sclerosis, osteophytes in valgus extension overload syndrome and posteromedial impingement
• coronoid process
  • coronoid process fracture
• medial (ulnar) collateral ligament complex (anterior and posterior bundle)  
  • elbow dislocation, valgus instability, advanced posterolateral rotatory instability
• medial epicondyle
  • golfer's elbow, medial epicondyle apophysitis
• common flexor and pronator origin
  • golfer's elbow
  • flexor-pronator mass injury

Triceps tendon, ulnar nerve and posterior soft tissues

Assessment of the following structures:

• distal triceps tendon
  • variant anatomy
  • triceps tendinopathy, triceps bony avulsion, tendon rupture
• olecranon bursa
  • olecranon bursitis
• cubital tunnel and ulnar nerve
  • variant anatomy: anconeus epitrochlearis muscle, thickened or absent retinaculum
  • ulnar nerve dislocation

Radiocapitellar articulation and proximal radio-ulnar joint

Assessment of the following structures:

• radiocapitellar cartilage and subchondral bony structures
  • chondral and osteochondral injury, subchondral fractures and subchondral cysts, osteoarthritic changes of the capitellum and radial head
  • lateral radiocapitellar compression, Osborne-Cotterill lesion
• lateral (radial) collateral ligament complex with the lateral ulnar collateral ligament and radial collateral ligament and the annular ligament
  • posterolateral rotatory instability
• medial epicondyle
  • tennis elbow
• common extensor origin
  • tennis elbow, tendon or muscle injury/tears
• variant anatomy: additional radial wrist extensor muscles

Pitfalls

• pseudo defect of the capitellum

Distal biceps tendon

Assessment of the distal biceps tendon insertion:

• biceps tendon rupture, partial tears
• postoperative changes, re-tear, heterotopic ossification

Volar soft tissues and median and radial nerves

Assessment of the following structures:

• brachialis, brachioradialis, supinator muscles, pronator teres muscle
  • muscle edema, muscle injury, brachialis tendon avulsion
• median nerve
  • pronator syndrome
  • anterior interosseous nerve compression syndrome
• radial nerve (between brachialis and brachioradialis muscle Arcade of Frohse)​
  • posterior interosseous nerve compression syndrome

Common pathology

• tennis elbow
• golfer's elbow
• elbow instability
• posterolateral rotatory instability
• valgus extension overload syndrome   
• biceps brachii tendon tear
• snapping triceps syndrome
• ulnar, median or radial nerve compression syndromes
• olecranon bursitis
• lipoma