Radiography Forearm Positioning Techniques

AP Forearm Positioning

• Hand supinated to prevent rotation of radius and ulna
• Straight tube angle
• Central ray perpendicular to mid radius/ulna
• Distance: 100-110cm
• Collimation: Include all skin edges, both wrist and elbow joints
• kVp: 50-60kVp
• mAs: 5mAs
• Grid: No
• Patient preparation: Remove artifacts (watches and jewelry)

AP Forearm Criteria

• Collimation: Include all anatomy, skin edges
• Alignment: Slight superimposition of radial head, neck and tuberosity over proximal ulna. Partially open elbow joint if the shoulder was placed in the same plane as the forearm.
• Anatomy: Entire Forearm, including wrist and distal humerus
• Density: Cortical outline and bony trabecular pattern visible
• Contrast: Soft tissue and bony interfaces visualized
• Markers: Side marker evident
• Identification: Appropriate labeling or anonymized

Lateral Forearm Positioning

• Patient seated with legs at right angle to table
• Entire Arm should be in the same plane
• Flex elbow 90 degrees and place medial aspect of forearm on image receptor
• Straight tube angle
• Central ray perpendicular to mid radius/ulna
• Distance: 100-110cm
• Collimation: Include all skin edges, both wrist and elbow joints
• kVp: 50-60kVp
• mAs: 5 mAs
• Grid: No
• Patient preparation: Remove artifacts (watches and jewelry)

Lateral Forearm Criteria

• Collimation: Include all anatomy, skin edges
• Alignment: Slight superimposition of radial head, neck and tuberosity over proximal ulna. Partially open elbow joint if the shoulder was placed in the same plane as the forearm.
• Anatomy: Entire forearm, including wrist and distal humerus in true lateral position. Superimposition of radius and ulna at distal end.
• Markers: Side marker evident
• Identification: Appropriate labeling or anonymized

Axial Lateral Elbow (Radial Head Trauma) Positioning

• Patient seated with arm bent at 90 degrees
• Hand pronated
• Elbow flexed at 90 degrees
• Hand pronated
• Tube angle 45 degrees towards patient
• Central Ray 45 degrees angled toward chest at mid elbow joint
• Distance: 100-110cm
• Collimation: Include skin edges, 5cm distal humerus, proximal forearm
• kVp: 55-65kVp
• mAs: 4-6 mAs
• Grid: No
• Patient preparation: Remove artifacts (clothing)

Axial Lateral Elbow (Radial Head Trauma) Criteria

• Collimation: Include all anatomy, skin edges
• Alignment: Elbow flexed at 90 degrees
• Anatomy: Radial head and neck free of superimposition, projected away from ulna. Capitellum seen.
• Density: Cortical outline and bony trabecular pattern visible
• Contrast: Soft tissue and bony interfaces visualized
• Markers: Side marker evident
• Identification: Appropriate labeling or anonymized

Toes (Dorso-Plantar) Positioning

• Patient seated on table
• Knee bent and place foot on image receptor
• Tube angle: 15 degrees angled towards heel
• Central Ray: perpendicular to third metatarso-phalangeal joint (MTP)
• Distance: 100-110cm
• Collimation: Include skin edges and adjacent toes.
• kVp: 55 kVp
• mAs: 3 mAs
• Grid: No
• Patient preparation: Remove artifacts (shoes, socks)

Toes (Dorso-Plantar) Criteria

• Collimation: Include all anatomy, skin edges and adjacent toes.
• Alignment: Toes separated without rotation of phalanges, concavity demonstrated on both sides of metatarsal shafts.
• Markers: Side marker evident
• Identification: Appropriate labeling or anonymized

Sesamoids Tangential View Positioning

• Patient lying prone on table or seated
• Foot positioned with first toe flexed and ball of foot perpendicular to image plate. Patient can remain seated with foot flexed and tape tensioning the toes back.
• Straight angle tube
• Central Ray: Centered on second metatarsal
• Distance: 100-110cm
• Collimation: Include skin edges, metatarsal head and sesamoids
• kVp: 50-55kVp
• mAs: 2-4 mAs
• Grid: No
• Patient preparation: Remove artifacts (shoes, socks)

Sesamoids Tangential View Criteria

• Collimation: Include all anatomy, skin edges
• Alignment: Open joint spaces between sesamoids and first metatarsal
• Anatomy: Both sesamoids seen in profile without superimposition
• Density: Cortical outline and bony trabecular pattern visible
• Contrast: Soft tissue and bony interfaces visualized
• Markers: Side marker evident
• Identification: Appropriate labeling or anonymized

Foot Dorso-Plantar View Positioning

• Patient seated on table
• Foot positioned flat on image plate
• Tube angle: 10 degrees towards heel
• Central Ray: Centered on base of third metatarsal
• Distance: 100-110cm
• Collimation: Include all anatomy of interest
• kVp: 50-55kVp
• mAs: 3-4 mAs
• Grid: No
• Patient preparation: Remove artifacts (shoes, socks)

Foot Dorso-Plantar View Criteria

• Collimation: Include all anatomy, skin edges
• Alignment: No rotation of foot, long axis of image plate aligned with long axis of foot.
• Anatomy: Toes to tarsals included, slight overlap of 2nd-5th metatarsal bases.
• Density: Cortical outline and bony trabecular pattern visible
• Contrast: Soft tissue and bony interfaces visualized
• Markers: Side marker evident
• Identification: Appropriate labeling or anonymized

PA Rosenberg Positioning:

• Tube angle: Parallel to tibial plateau, appx. 10 degrees caudal angle
• Central Ray: Centered to midline of knee at level of joint space
• Distance: 100-110cm
• Collimation: Include all anatomy of interest
• kVp: 60-70kVp
• mAs: 12-16 mAs
• Grid: Yes
• Patient preparation: Comfortable position, quick exposure

PA Rosenberg Criteria

• Collimation: Include all anatomy and skin edges
• Alignment: No rotation of femur or tibia. Tibial plateau in profile.
• Anatomy: Distal femur, proximal tibia and fibula. Open femoro-tibial joint spaces, intercondylar fossa visualized.
• Density: Cortical outline and bony trabecular pattern visible
• Contrast: Soft tissue and bony interfaces visualized
• Markers: Side marker evident, labeled “Wt Bearing Rosenberg”
• Identification: Appropriate labeling or anonymized

Horizontal Beam Lateral Knee View Positioning:

• Patient supine on bed, knee extended
• Performed medio-laterally with image receptor resting between patient’s knees.
• Tube angle: Perpendicular to long axis of knee.
• Central Ray: Angled appx 5 degrees caudally at distal portion of lateral condyle, superimposing the femoral condyles with medial femoral condyle appearing larger.
• Distance: 100-110cm
• Collimation: Include all anatomy of interest
• kVp: 60
• mAs: 12 mAs (adjust based on knee thickness)
• Grid: No

Horizontal Beam Lateral Criteria:

• Collimation: Include all anatomy, skin edges
• Alignment: Superimposed femoral condyles, true lateral. Patella in profile and open femoro-patellar joint space. Tibial plateau in profile.
• Anatomy: Distal femur, proximal tibia and fibula in lateral profile.
• Density: Cortical outline and bony trabecular pattern visible
• Contrast: Soft tissue and bony interfaces visualized
• Markers: Side marker evident, labeled “Horizontal Beam Lateral”
• Identification: Appropriate labeling or anonymized

This quiz focuses on the essential positioning techniques and criteria for imaging the forearm in radiography. It covers both AP and lateral views, emphasizing parameters like collimation, alignment, anatomy, and density. Test your knowledge on the crucial factors for successful forearm imaging.