What SID is recommended for a medial oblique radiograph of the fifth digit?

What SID is recommended for a medial oblique radiograph of the fifth digit?

• A. 28 inches (71 cm)
• B. 40 inches (102 cm)
• C. 52 inches (132 cm)
• D. 72 inches (183 cm)

Answer: (B)

A mid-range SID around 40 inches is used for imaging a single finger because it gives a good balance of sharp detail and controlled magnification for the small bones of the digit. With a shorter distance, like 28 inches, the image would be more magnified and edges of the bones could blur, making it harder to see cortical margins and joint surfaces clearly. A much longer distance, such as 52 or 72 inches, would reduce image brightness and may require more technique to achieve the same exposure, while also risking cropping or positioning difficulties for such a small structure. Therefore, 40 inches (about 102 cm) provides optimal image quality for a medial oblique view of the fifth digit.

A mid-range SID around 40 inches is used for imaging a single finger because it gives a good balance of sharp detail and controlled magnification for the small bones of the digit. With a shorter distance, like 28 inches, the image would be more magnified and edges of the bones could blur, making it harder to see cortical margins and joint surfaces clearly. A much longer distance, such as 52 or 72 inches, would reduce image brightness and may require more technique to achieve the same exposure, while also risking cropping or positioning difficulties for such a small structure. Therefore, 40 inches (about 102 cm) provides optimal image quality for a medial oblique view of the fifth digit.