Ghost like shadow is seen in
Structures located between the X-ray source and moving center of rotation (orange zone) cast ghost images.
On the panoramic image, ghost images appear on the image on the opposite side of its true anatomic location and at a higher level, because of the upward inclination of the X-ray beam. Because the object is located outside of the focal plane and close to the X-ray source, the ghost image is blurred and significantly magnified. Several anatomic structures cast ghost images.
MRI
OPG
CT
Cephalogram