Obj. Wrist & Hand

List the ossification Centers and fusion and closure of the bones that make up the wrist & hand?

• Ossification of the wrist and the hand begins in the shaft of the metacarpals, phalanges, radius and ulna in the 8th week of fetal life.

• Carpals are cartilaginous at birth and ossify from a single center for each bone.

Carpals are complete at age

14-16 yrs. for boys and 1-2 yrs. earlier for girls.

2° centers appear for the distal MC and proximal phalanges at

age 2 years and close at 16-18 yrs.

2° centers appear for the distal radius at 1 year and ulna

at 5-6 years and close at 18-20 years.

The routine radiographic evaluation of the hand includes which three projections?

Posterior-Anterior (PA)

Lateral

Oblique

What are the three common optional projections of the wrist and what is special about each?

ULNAR DEVIATION

RADIAL DEVIATION

CARPAL TUNNEL VIEW

The basic CT exam of the WRIST extends from where to where (Superior-Inferior) and from where to where (Medial-Lateral)?

• Scanning plane is perpendicular to the long axis of the radius

• Field of view extends from the distal radius and ulnar metaphysis to the metacarpal bones.

• Slices are less than 1mm thick, and reconstructed to 2-3 mm thick; from 40-100 are reviewed in each plane.

Scanning plane

is perpendicular to the long axis of the radius

Field of view

extends from the distal radius and ulnar metaphysis to the metacarpal bones.

Slices

are less than 1mm thick, and reconstructed to 2-3 mm thick; from 40-100 are reviewed in each plane.

What are the three imaging planes for CT and MRI of the Wrist

Axial- allow visualization in cross-section and superior to inferior

Sagittal- allows visualization from lateral to medial

Coronal- allows visualization from front to back

What do the ABCs stand for when evaluating a CT of the WRIST?

A = Alignment

B = Bone density

C = Cartilage spaces

S = Soft tissue

What are the two basic pulse sequences for MRI of the WRIST and what do these sequences highlight?

Anatomy-defining sequences (T1 - weighted)

Fluid-sensitive sequences (T2 - weighted)

What do the ABCDs stand for when evaluating an MRI of the wrist?

A = Alignment/anatomy

B = Bone signal

C = Cartilage

D = eDema

S = Soft tissues

Anechoic Structures:

No echo appear black

Water (fluid)-synovial fluid, hemiarthrosis

Cysts (particularly fluid-filled)

Hyperechoic:

Highly reflective and appears white to light gray

Bone ( always dark behind it as no echo)

Fibrils of Connective tissue of tendon and ligament

Hypoechoic:

Low reflections and appears dark gray-gray

Muscle - has some hyperechoic connective tissue

Nerve - hypoechoic spots on a hyperechoic background (honey-comb appearance)

What are the six areas of an ultrasound evaluation of the wrist??

VOLAR 1 (CENTER OF WRIST)

VOLAR 2 (THUMB SIDE)

VOLAR 3 (ULNAR SIDE)

DORSAL 1 (CENTER OF WRIST)

DORSAL 2 (THUMB SIDE)

DORSAL 3 (ULNAR SIDE)

Dorsal 1-Tranverse:

Extensor compartment 3-Lister’s tubercle.

Volar 1-Transverse:

Median nerve.

Volar 3-Longitudinal:

Flexor carpi ulnaris tendon.