Panoramic errors result in image presentations that may be due to patient preparation, machine preparation, patient positioning, tissue projection, patient movement, shoulder interference of a combination thereof.
Technique errors can result from difficulties encountered from each of the three stages in panoramic technique:
The features of these errors on radiographs are characteristic and are therefore usually readily self-diagnostic.
- Metallic artifacts – The most common patient preparation error is failure to remove metallic or radiodense objects – This causes two problems:
- First, they produce a radiopaque outline of themselves, usually providing a telltale indication of the error.
- Second, they may produce so-called “ghost images.” Ghost imaging is a normal component of the panoramic projection and occurs when an object is penetrated twice by the x-ray beam. Structures or objects that are located posterior to (behind) the center of rotation and the x-ray source tend to be ghosted onto the contralateral side of the image. Ghost images have specific recognizable characteristics that are viewable on the panoramic image.