Forearm, Elbow, Humerus

Question 1

AP Forearm positioning

Answer 1

Seated at the end of the table.
Hand Supinated. (Leaned forward)
Elbow extended.
IR long axis parallel with forearm.
IR centered mid forearm.
Humoral epicondyles equidistant from IR.

Question 2

AP Forearm Central Ray (CR)

Answer 2

Enters perpendicular to the midpoint of the forearm.

Question 3

AP Forearm Collimation

Answer 3

2” distal to wrist joint and proximal to elbow joint.
1” on the sides
Place side marker in collimation field.

Question 4

AP Forearm Structures Shown

Answer 4

Entire Forearm, wrist & distal humerus.
Slight imposition of radial head, neck and tuberosity over proximal ulna.
No elongation or foreshortening of humeral epicondyles.
Partially open elbow joint.
Open radioulnar space.
Bony Trabecular detail and surrounding soft tissue.

Question 5

Lateral Forearm positioning

Answer 5

Seated at end of table.
Elbow flexed 90° with medial side against IR.
Long axis of IR parallel with forearm.
Adjust extremity to be true lateral (hand sandwich) to ensure epicondyles and styloid processes are superimposed and perpendicular to IR.
Thumb side up.

Question 6

Lateral Forearm Central Ray (CR)

Answer 6

Enters perpendicular to the midpoint of the forearm.

Question 7

Lateral Forearm Collimation

Answer 7

2” distal to wrist and proximal to elbow
1” on the sides

Question 8

Lateral Forearm Structures Shown

Answer 8

Entire Forearm, wrist and distal humerus.
Superimposition of radius/ulna at distal end.
Superimposition for radial head over coronoid process.
Radial tuberosity facing anteriorly
Super imposed epicondyles.
Flexed elbow 90°
Bony trabecular and surrounding soft tissue.

Question 9

AP Elbow positioning

Answer 9

Extend the elbow, center elbow on IR
IR long axis parallel with long axis of part.
Patient lean laterally until epicondyles and anterior surface of elbow at parallel to the IR
Supinate the hand

Question 10

AP elbow central ray (CR)

Answer 10

Perpendicular to the elbow joint.

Question 11

AP elbow structure shown

Answer 11

Radial head, neck and tuberosity slightly superimposed over the proximal ulnar.
Elbow joint centered to exposure field.
Open humeroradial joint.
No rotation of epicondyles
Bony trabecular detail and surrounding soft tissues

Question 12

Lateral elbow positioning

Answer 12

Flexed elbow 90°
Place humerus and forearm in contact with IR
Adjust hand and wrist in (true) lateral
IR centered to elbow joint.

Question 13

Lateral elbow central ray (CR)

Answer 13

Perpendicular to the elbow joint

Question 14

Lateral elbow Collimation

Answer 14

3” proximal and distal to the elbow joint

Question 15

Lateral elbow structures shown

Answer 15

Elbow joint centered
Elbow in true lateral
Superimposed, humeral epicondyles.
Radio tuberosity, facing anteriorly
Radiohead partially super imposing the coronoid process
Olecranon process in profile
Elbow flexed 90°
Bony trabecular detail & any elevated fat pads in the soft tissue at the anterior and posterior distal humerus in the anterior proximal forearm

Question 16

AP humerus positioning
(Upright)

Answer 16

Standing. Adjust the height of the IR to place it upper margin, approximately one and a half inches above the level of the humeral head.
Abduct the arm slightly, and supinate the hand
Chrono plane passing through epicondyles should be parallel with IR plane for the AP or PA projection l

Question 17

AP humerus central Ray (CR)

Answer 17

Perpendicular to the mid portion of the humerus and the center of the IR.

Question 18

AP humerus structures shown

Answer 18

Elbow and shoulder joints visible, but slightly distorted due to beam divergence
Humeral epicondyles without rotation
Humeral head and greater tubercle in profile
Outline of lesser tubercle, located between the humeral head, and the greater tubercle
Bony tubercular, detail, and surrounding soft tissue

Question 19

Lateral humerus positioning

Answer 19

Top margin of the IR approximately 1.5” above the level of the humeral head
Internally rotate the arm flex, the elbow, approximately 90° in place interior hand on hip
Epicondyles should be perpendicular to IR

Question 20

Lateral humerus central ray (CR)

Answer 20

Perpendicular to the mid portion of the humerus, and the center of the IR.

Question 21

Lateral humerus Collimation

Answer 21

2” distal to the elbow and superior to the shoulder
1” on the sides

Question 22

Lateral humerus structure shown

Answer 22

Elbow and shoulder joints visible, but slightly distorted, due to beam divergence
Superimposed humeral epicondyle
Lesser tubercle in profile on medial aspect
Greater tuber super imposed over the Humeral head
Bony tubercular detail, and surrounding soft tissues

Question 23

AP elbow Collimation

Answer 23

3” proximal and distal to the elbow joint
1” on the sides

Question 24

AP Humerus Collimation

Answer 24

2” distal to the elbow joint and superior to the shoulder
1” on the sides