LATERAL FOREARM 

Pathology demonstrated :

Fractures and dislocations of the radius or ulna

• Pathologic processes, such as osteomyelitis or arthritis

IR SIZE :

30 × 35 cm (11 × 14 inches), for  smaller patients; 35 × 43 cm (14 × 17  inches), for long forearm. 

IR POSITION :

lengthwise / tabletop

Shielding:

Shield radiosensitive tissues outside region of interest. 

Patient position : 

Seat patient at end of table, with elbow flexed 90°.

Part position:

Drop shoulder to place entire upper limb on same horizontal plane.

• Align and center forearm to long axis of IR; ensure that both wrist and elbow joints are included on IR.

• Rotate hand and wrist into true lateral position, and support hand to prevent motion, if needed. (Ensure that distal radius and ulna are superimposed directly.)

• For heavy muscular forearms, place support under hand and wrist as needed to place radius and ulna parallel to IR.

CR : 

CR perpendicular to IR, directed to mid-forearm . 

Collimation:

Collimate both lateral borders to the actual forearm area. Also, collimate at both ends to avoid cutting off anatomy at either joint. Considering divergence of the x-ray beam, ensure that a minimum of 3 to 4 cm (1 to 2 inches) distal to wrist and elbow joints is included on IR.

criteria:

Anatomy Demonstrated: • Lateral projection of entire radius and ulna, proximal row of carpal bones, elbow, and distal end of the humerus are visible as well as pertinent soft tissue, such as fat pads and stripes of the wrist and elbow joints.

Position: 

• Long axis of forearm should be aligned with long axis of IR. • Elbow should be flexed 90°. 

• No rotation as evidenced by head of ulna being superimposed over the radius, and humeral epicondyles should be superimposed. 

• Radial head should superimpose coronoid process, with radial tuberosity demonstrated. 

• CR and center of collimation field should be to midpoint of the radius and ulna.

Exposure: 

• Optimal density (brightness) and contrast with no motion should visualize sharp cortical margins and clear, sharp bony trabecular markings and fat pads and stripes of the wrist and elbow joints.