Foreshortening occurs when which condition is met?

• A. Central Ray Parallel to the Receptor, Object Not Parallel
• B. Central Ray Perpendicular to the Receptor, Object Not Parallel
• C. Central Ray Perpendicular to the Object, Receptor Not Parallel
• D. Central Ray Perpendicular to the Receptor and the Object

Answer: (B)

Foreshortening is a type of shape distortion that happens when the part being imaged is not lying parallel to the image receptor while the X-ray beam is directed perpendicular to that receptor. In this setup, the beam hits the anatomy at an angle relative to its length, so the projection of the part onto the receptor is shortened. That’s why the condition where the central ray is perpendicular to the receptor and the object is not parallel to the receptor produces a foreshortened image. If the object were parallel to the receptor or the beam were angled differently, you’d see less foreshortening or a different distortion like elongation.