13. Imaging of the Upper Limb Flashcards
What are the advantages and disadvantages of X-ray?
A: Cheap, quick, good for bone (high spatial resolution), low radiation dose
D: Poor contrast resolution (bad for soft tissue), 2D image
What are the advantages and disadvantages of CT?
A: Quick, widely available
Cross-sectional images
Good for soft tissue (high contrast resolution)
D: Radiation higher, IV contrast risk
What are the advantages and disadvantages of MRI?
A: Good contrast resolution (soft tissue), can be used for specific applications (e.g. view the brachial plexus), no radiation
D: Limited availability, patient experience, £££, magnet/contrast risks, unsuitable for trauma
What are the advantages and disadvantages of US?
A: cheap, easily available, no radiation, specific applications
D: limited field of view, requires expert handler
What do the following stand for when searching X-Rays?
A
A
B
C
S
S
A - Adequacy
A - Alignment
B - Bones
C - Cartilage / Joint spaces
S - Soft tissues
S - Satisfaction of search (check again)
Which is the most common dislocation of the shoulder?
Which is the rarest?
Most common = anterior dislocation
Inferior = rarest
How do Ps with a posterior dislocation of the shoulder present?
Unable to lower their arm
What pathology is seen here?
Anterior dislocation of glenohumeral joint
Normal or abnormal?
Normal - young P with epiphysis of humerus seen in the neck.
Normal or abnormal?
Abnormal - clavicle lateral end displaced = dislocation of acromioclavicular joint.
What signs on xray can indicate osteoarthritis in a joint?
Reduced joint space
Osteophytes
Subchondral sclerosis
What is subchondral sclerosis and how does it appear on X-ray?
Subchondral sclerosis is a thickening of bone that happens in joints affected by osteoarthritis.
In Xray it can appear as a brighter white joint
What does this x-ray show?
Osteoarthritic changes of the shoulder - reduced subacromial space
What type of scan is this?
What is the go-to scan for rotator cuff assessment?
US
When is MRI used for rotator cuff assessment?
When there is complex injury / instability of the joint
What is used to assess the glenoid labrum or for ligament lesions?
MR arthrography - where contrast agent is injected into the joint
How do bursae appear on US?
Thin and anechoic (dark)
How do tendons appear on US?
Homogenous in texture with a brightness and smooth contour
In what order do ossification centres develop on children between 6 and 12?
CRITOL rule
Capitellum
Radial head
Internal (medial) epicondyle
Trochlear
Olecranon
Lateral Epicondyle
What are raised fat pads on an elbow xray a sign of?
That there is a fracture present
When is CT used for an elbow?
To assess bone or soft tissue tumours when MRI is contraindicated.
Can be used in trauma cases to establish the extent of a fracture
To make 3D reconstruction to allow assessment before surgery
Not commonly performed.
When is MRI of the elbow done?
To determine soft tissue pathology (inc tumours)
Avascular necrosis of the bone
What muscles does the radial nerve run between?
The brachialis and brachioradialis
Where do the ulnar nerve branches pass in the hand?
Deep - dorsal and distal to hook of hamate.
Superficial - distally into the palm
What is wrong in this X-ray?
Lunate dislocation
What is wrong in this X-ray?
Colles fracture - fracture of radius with dorsal displacement
What type of image is this?
CT Scan
What type of image is this?
MRI
What is the problem with a scaphoid fracture?
Part of the fractured bone can die because the blood vessel passes through the scaphoid itself = avascular necrosis of the scaphoid.
What joints does RA usually affect?
MCP
PIP
Ulnar styloid joint
How can RA appear on MRI?
Multiple bone erosions
Multiple bone erosions and destruction of the TFCC by an aggressive, (predominantly) hypervascular pannus.
What scan is best for early detection of RA? What does it show?
US & Doppler
US - very sensitive - can show early stages of inflammation, synovial hypertrophy and erosion
Doppler - shows inc blood supply in inflamed joint (synovitis)
What late changes are seen to the joints in RA?
Carpal fusion (ankylosis)
Joint subluxation
When is X-Ray most commonly used for hands?
For trauma
What is MRI used for in hands?
Assessing soft tissue masses, bone infection and RA
Can also show acute synovitis and erosions
What is US used for in hand?
Assessing inflammatory changes & bony erosions (RA)
What pathology is this?
Extensor tenon avulsion
What is mallet finger? How does it present?
Is avulsion of the extensor tendon from the DIP joint attachment.
Ps present with inability to extend the finger at the DIP or PIP joint. Bony fragment may be seen at the insertion of the tendon.
What pathology is this?
RA
How does RA present?
Symmetrical
Affects MCP, PIP and the carpal joints
Can get subluxation of the joints
Can get bone erosions
How does OA present?
Usually asymmetric
Affects the DIP joints
Get osteophytes
Bright joints on X-ray fro,
Reduced joint space
Can get degenerative changes between scaphoid, trapezium and triquetral
