Hand and Wrist
What is an alternative for a PA projection of the wrist?
AP projection of the wrist.. Because it shows the intercarpal spaces BETTER than the PA. It places the carpals more parallel to the IR.
What is the most commonly fractured carpal bone?
scaphoid
What does a lateral extension image better demonstrate than a fan lateral?
Any foreign bodies, and arthritis
What projection is the Gaynor Hart Method? -Hand position -CR:
Tangential Projection (skimming of the part) -Hand Position: Hyperextension -CR: Angled 25-30 Degrees
How can you tell if you didnt over-rotate or under-rotate for the PA oblique of the hand?
This is by looking at the heads of digit 3,4, and 5. They should be slightly overlapped/superimposed.
What specialty projection will you not be able to sit the patient sideways at the end of the table?
PA Scaphoid projection
How do you position the hand for a PA projection ?
-Hand is pronated -Fingers slightly spread apart -Hand is parallel to the IR to prevent foreshortening and closed JS
How do you position the patients hand in a PA oblique projection?
-Hand starts off pronated, rotate the hand laterally 45 degrees
How do you critique the lateral projection of the wrist?
-Head of metacarpals to as much of the distal radius and ulna -Superimposition of the 2-5 digit -Distal radius and ulna will be superimposed -STM BTD
What is the critique for a lateral projection of the hand?
-Superimposition of digits 2-5 -Distal Radius and Ulna will be superimposed -BTM and STM
What is the critique for the PA projection of the hand?
-To include entire hand and carpals -No rotation of phalanges and metacarpals (by equal concavity) -Open JS
What is the Technical factors for the hand? -kVp -mAs -SID -Field Size
-kVp: 55-65 -mAs: 2-3 -SID: 40 Inches -Field Size: 10x12
For the registry, you should have the CR for the oblique at the 3rd MCP JS, but which MCP joint is more ideal to center in the "real world"?
2nd MCP JS
Where is the CR for the PA projection of the hand?
3rd Metacarpal JS (Middle of hand)
Where do you center for a PA oblique projection?
At the Mid carpals
Where is your CR for the PA wrist?
At the mid carpals (Middle of the wrist)
What is the exposure factors for all hand projections?
BTM and STM
How do you position the patient for a PA scaphoid? -Center -Collimation
Center wrist to IR, curl fingers, bend hand to the wrist TOWARDS the ulna (ulnar deviation) -Angle 10-15 degrees Center: Scaphoid Collimation: Do NOT have to include much of the radius and ulna
Where do you collimate for the PA projection of the hand?
From the distal phalanges to an inch off the distal radius and ulna
What is the projection done that shows the carpal tunnel?
Gaynor Hart Method
What is the routine projections for the hand?
PA, PA Oblique, Lateral
What is the routine for a wrist?
PA, PA Oblique, and Lateral
Where is the CR for the Lateral projection?
The 2nd MCP JS
What is the name of the lateral projection that best demonstrates each phalanges?
The Fan Lateral.
How do you critique an oblique projection of the wrist?
-Head of the metacarpals to as much of the radius and ulna -makes sure metacarpals of 3-5 are mostly superimposed -Slight overlap of radius and Ulna -STM BTD
What are the Technical Factors for a wrist? -kVp -mAs
-kVp: 55-65 -mAs:3-4
What are the two reasons why you would want to curl the patients fingers in for a PA wrist?
1. To reduce OID of the carpal bones 2. It places the carpal bones more parallel to the IR which in turn open up the intercarpal spaces
Why is the oblique where the part is parallel to the IR a better option than the oblique which is NOT parallel?
Because you can see the JS where as an oblique position where the part is NOT parallel to the IR, you cannot see the JS.
How do you position for a lateral projection of the wrist?
Hand and wrist are at 90 degrees, fingers are extended
How do you position the patients hand for a PA wrist projection?
Hand is in pronation with fingers curled
How do you position a patient for a PA oblique projection of the wrist?
Hand is in pronation, fingers slightly curled, wrist at middle of IR, ROTATE 45 degrees laterally.
Where do you collimate for a lateral projection of the wrist?
Head of the metacarpals to as much of the distal radius and ulna
How do you collimate for a PA wrist?
Head of the metacarpals to as much of the distal radius and ulna as possible
Where do you collimate for a oblique projection of the wrist?
Head of the metacarpals to as much of the radius and ulna.
Where do you center for a lateral projection of the wrist?
Mid carpal region
How do you critique a PA projection of the wrist?
No or minimum overlap of distal radius and ulna, equal concavity of metacarpals -Head of metacarpals and as much of the distal radius and ulna as possible. (This is because if someone fractures the wrist, the radius or ulna is usually whats fractures than the carpal bone themselves) -STM and BTD
How do you position for a fan lateral?
Thumb will be up, hand will be up 90 degrees in a lateral. Then, the patient will separate each of the fingers so you can see each one.
When would you do a AP oblique projection? How would you position?
To better show the pisiform. -From a lateral, rotate externally 45 degrees
