Chapter 5: Essential projections of the digits and thumb Flashcards
What are the essential projections for digits 2 to 5?
PA, Lateral, PA oblique
Where does the CR enter for a PA image on digits 2 to 5?
It enters at the patients proximal interphalangeal joint (PIP)
What should the collimation be for a PA image on digits 2 to 5?
1 inch on all sides of the digits, including 1 inch proximal to the MCP joint
What is the position for a lateral image on second and third digits?
Extend affected digit with lateral surface in contact with IR
(mediolateral projection)
close the rest of the fingers into a fist
What is the position for a lateral image on fourth and fifth digits?
Extend affected digit with medial surface in contact with IR
lateromedial projection
close the rest of the fingers into a fist
Where should the central ray be and where should it enter the patient for a lateral digit image on digits 2 to 5?
It enters the patient at the PIP joint of affected digit
What is the position like for a PA oblique image on digits 2 to 5?
Palmar surface resting on 45 - degree wedge sponge or hand rotated with digits extended parallel with the IR plane so that the IP joint spaces are open.
the digit of interest should be separated from the rest with no soft tissue overlap
Where should the central ray be and enter for PA oblique image on digits 2 to 5
perpendicular to PIP joint of the affected digit. It enters at the pip joint of affected digit.
What are the essential projections for a thumb image?
Anteroposterior (AP)
Lateral
PA oblique
AP thumb patient position
Hand in extreme medial internal rotation
posterior surface of thumb on IR
MCP joint centered to IR
What should collimation be for an AP thumb?
1 inch on all sides of the digit, including 1 inch proximal to CMC joint
What should the position be like for a lateral thumb?
palmar surface on IR
align long axis of thumb parallel
center mcp joint to IR
rotate thumb until lateral surface is on IR (mediolateral projection)
central ray for lateral thumb
perpendicular to mcp joint of thumb
PA oblique thumb position
palmar surface on IR
Ulnar deviate hand slightly
