TOE X - RAY | AP OBLIQUE

AP OBLIQUE PROJECTION - MEDIAL OR LATERAL ROTATION : TOES

Pathology Demonstrated:

• Fracture and/or dislocations of the phalanges of the digits in question are demonstrated. Some pathologies such as osteoarthritis and gouty arthritis (gout) may be evident, especially in the first digit, big toe pain.

Technical Factors:

• IR size - 18 x 24 cm (8 c 10 inches), crosswise
• Divide in thirds, crosswise
• Detail screen, tabletop
• Digital IR - use lead masking
• 50 to 60 kV range
• mAs 2

Shielding:

• Place lead shield over pelvic area to shield gonads.

Patient Position:

• Take radiograph with patient supine or seated on table; knee should be flexed with plantar surface of foot resting on cassette.

Part Position:

AP Oblique, Medila Rotation

• Center and align long axis of digit(s) to CR and long axis of portion of IR being exposed.
• Ensure that MTP joint(s) of digit(s) in question is (are) centered to CR.
• Rotate the leg and foot 30 to 45 degree medially for the first, second, and third digits and laterally for the fourth and fifth digits.
• Use 45 degree radiolucent support under elevated portion of foot to prevent motion.

Central Ray:

• CR perpendicular to IT, directed to MTP joint(s) in question
• Minimum SID of 40 inches (100 cm)

Collimation:

• Collimate on four sides to include phalanges and a minimum of distal half of metatarsals. On side margins, include a minimum of one digit on each side of digit(s) in question.

CR and DR:

• Close collimation and lead masking are important over unused portions of image plate to prevent  fogging from scatter radiation to the hypersensitivity image plate or receptor.

Radiographic Criteria:

Structure Shown:

AP Oblique, Medila Rotation

• Digit(s) in question and distal half of metatasals should be included without overlap (superimposition).

Position:

• Long axis of foot aligned to long axis of portion of IR being exposed.
• Correct obliquity should be evident by increased concavity on one side of shafts and by overlapping of soft tissue of digits.
• Heads of metatasals should appear directly side by side with no (or only minimal) overlapping.

Collimation and CR:

• Collimation borders should be visible on four sides with the center (CR) at the  MTP joint(s) of interest.
• Interphalangeal and MTP joints of interest appear open, indicating correct CR.

Exposure Criteria:

• No motion as evidenced by sharply defined cortical margins of the bone and detailed bony trabeculae.
• Optimal contrast and density will allow visualization of bony cortical margins and trabeculae and soft tissue sturctures.