In panoramic imaging, an object located posterior to the center of rotation can produce what artifact?

• A. Double image
• B. Ghost image
• C. Air-space
• D. Distortion of real image

Answer: (A)

In panoramic imaging, where an object sits relative to the center of rotation changes how its shadow is projected on the film. If an object is posterior to the center of rotation, the rotating beam can intersect that same object twice during the sweep, producing two projections of the same structure on the image. That results in a double image artifact—the same anatomy appears duplicated on the radiograph.

This differs from ghost images, which occur when objects are anterior to the center of rotation and create a single, contralateral image that looks like a ghost. Keeping in mind the geometry of the panoramic system helps you anticipate why a posterior object would show up as two images rather than a single ghost on the opposite side.