팔꿈치 관절의 MRI Checklist

1. Bones/Cartilage 

1) Capitellar pseudodefect 

2) Bare area “trochlear cortical notch or groove” (devoid of cartilage) and “transverse trochlear ridge” of olecranon seen on sagittal 3) Radiocapitellar joint, Ulnohumeral joint 

4) Prox RUJ : Panner’s, OCL 

- MIMIC : pseudodefect posterior non-articular capitellum has abrupt notch-like slope on coronal image (but no edema), Epicondylitis, Stress fx, Posterior dislocation

2. Ligaments (coronal) 

1) Radial(lateral) collateral ligaments : RCL, LUCL, Annular ligament 

① Evaluate integrity of common extensor tendon 

② Lateral synovial fringe (radiocapitellar meniscus; seen on coronal), Tennis elbow, Radial nerve entrapment 

2) Ulnar(medial) collateral ligaments : Anterior bundle UCL, Posterior bundle, Transverse bundle 

① Evaluate integrity of common flexor tendon 

② Golfer’s elbow, Valgus instability

3. Muscles (axial and sagittal) 

1) Anterior compartment : Biceps brachii tendon, Brachialis 

2) Posterior compartment : Triceps brachii, Anconeus 

3) Medial compartment : Common flexor tendon, Flexors of wrist/hand, Palmaris longus, Pronator teres 

4) Lateral compartment : Common extensor tendon, Extensors of wrist/hand, Supinator, Brachioradialis 

4. Nerves (axial T1 and T2) 

1) Neuropathy 

① Nerve : increased T2 signal, thickened nerve, indistinct fascicles, fluid around nerve

② Muscle : acute neurogenic edema, late fatty infiltration and muscle atrophy)

2) Ulnar nerve (injury more common than other nerves; located posterior to medial epicondyle) 

① Cubital tunnel syndrome 

② Look for “surrounding” increased T2 signal with enlarged or flattened or irregular nerve (may have magic angle on PD imaging) 

3) Median nerve 

① Best seen on prone imaging 

② Pronator syndrome, Anterior interosseous syndrome, Median neuropathy 

4) Radial nerve 

① Located btwn brachialis and brachioradialis muscle 

② Radial neuropathy, Radial tunnel syndrome or Posterior interosseous syndrome

5. Misc 

1) Effusion 

2) Loose bodies 

3) Bursitis(Bicipitoradial bursa, Interosseous bursa, Olecranon bursa) 

4) Epitrochlear adenopathy

5) Steroid injection for epicondylitis (peritendinous approach); PRP injection (intratendinous approach)