Wrist
The anatomy of the hand and wrist is very complex. There
are many joints and internal structures in the hand and wrist which
allow us to perform a great variety of functions from grasping, to
writing and picking up objects. Injury or pain to the wrist or hand
can therefore be very debilitating. Due to the complexity of the
wrist, clinical examination alone may not be able to isolate the
cause of symptoms.
MRI is the imaging modality of choice in many
circumstances. By using a dedicated wrist coil it is possible to
obtain images of a very high quality - which aids diagnosis. A
multitude of conditions affect the wrist and hand some of which are
illustrated below.
Normal Wrist
The bones, cartilage and
ligaments all return normal signal. (Sequence T1 TSE Coronal)
Fracture of the Scaphoid
A scaphoid fracture is usually
caused by falling on an outstretched arm. The diagnosis can often
be made with an Xray of the wrist, but a proportion of scaphoid
fractures do not show up on Xray. Those fractures not seen on Xray
are clearly and easily identified with MRI. Scaphoid fracture is an
important diagnosis to make because if missed complications such as
non union(failure to heal) or avascular necrosis can result. Long
term problems such as pain, degenerative change and impairment of
function can result. Symptoms: Pain in the scaphoid region (the
hollow formed at the base of the thumb when extended) and wrist
swelling.
MRI
High
signal is seen across the neck of the scaphoid demonstrating an
undisplaced scaphoid fracture (sequence T2 FFE - Coronal).
Triangular Fibrocartilage Complex (TFCC) Tear
The Triangular Fibrocartilage
TFC is similar to the meniscal cartilage within the knee. It
overlies the far end of the ulna (one of the forearm bones) and is
part of the TFC complex. This provides support and some stability
to the carpal bones of the wrist and the distal radio-ulnar joint.
Tears may be caused by overuse, degeneration or trauma. Symptoms:
Pain in the ulnar side of the wrist which worsens with anterior
movement, ulna deviation and compression of the radio-ulnar
joint.
MRI
(high signal) through
the TFC. (Sequence T2 FFE - Coronal).
Case studies:
