A ghost image in a panoramic radiograph is caused by what?

A ghost image in a panoramic radiograph is primarily caused by the presence of metallic or radiodense objects in the patient's mouth or head during the exposure. These objects, such as jewelry, eyeglasses, or orthodontic appliances, can interfere with the image by creating a shadow or duplicate image that appears on the radiograph. The ghost image typically manifests as a transparent or faint double outline of the object adjacent to its original position, leading to misinterpretation of the anatomical structures.

The presence of these materials results in unnecessary artifacts that obscure the clarity of the radiograph, making it difficult to assess the underlying dental structures accurately. Therefore, it is crucial to ensure that all metallic and radiodense items are removed prior to taking a panoramic radiograph to prevent ghost images and ensure optimal image quality.

Other factors like patient movement or the reversal of film do not specifically create a ghost image but can lead to other types of artifacts or blurriness in radiographic images.