Which adjustment would improve visibility on oblique hand radiographs when the phalanges are foreshortened?

Which adjustment would improve visibility on oblique hand radiographs when the phalanges are foreshortened?

• A. Rotate the hand from 45-55 degrees
• B. Rest the thumb and fingertips on the image receptor
• C. Use a block to place digits parallel to the image receptor
• D. Move the central ray to the first metacarpophalangeal joint

Answer: (C)

Foreshortening occurs when the bones aren’t parallel to the image receptor, causing loss of length and edge detail. Placing the digits parallel to the receptor, with a block supporting them, directly reduces this distortion. That alignment keeps the phalanges and joints in true projection, improving visibility of bone margins and joint spaces. Other adjustments don’t address the core issue: changing the oblique angle alters projection, not the alignment to the IR, and simply resting the hand or shifting the central ray doesn’t ensure parallelism of the digits to the image receptor.

Foreshortening occurs when the bones aren’t parallel to the image receptor, causing loss of length and edge detail. Placing the digits parallel to the receptor, with a block supporting them, directly reduces this distortion. That alignment keeps the phalanges and joints in true projection, improving visibility of bone margins and joint spaces. Other adjustments don’t address the core issue: changing the oblique angle alters projection, not the alignment to the IR, and simply resting the hand or shifting the central ray doesn’t ensure parallelism of the digits to the image receptor.