Tomography
is a special technique to show in detail images of structures
lying in a predetermined plane of tissue, while blurring or
eliminating detail due to images of structures in other planes.
The more complex the motion, the more effective the elimination
of structures outside the focal plane.
Hypocycloidal Motion:
Examination of the wire phantom graphically illustrates that
when using the hypocycloidal motion, there is uniform blurring
of all wires. All elements of the phantom outside the plane
of focus experience uniform blur and do not distort the image
of the focal plane. A sharp image of only one wire will result.
Linear Motion: Examination
of the wire phantom graphically illustrates that the blurring
pattern of a linear tomographic system is very irregular and
incomplete. Irregular blurring with linear obscuring movements
can create false images in the plane of focus. Any anatomy
within approximately 30cm of the focal plane can appear in
the image and cannot be distinguished from the anatomy inside
the focal plane. This phenomenon suggests that a linear tomogram
does not record the image of a section plane, but rather it
records an irregular plane of varying depths.
"The single most significant factor to influence the quality
of a tomogram is the spatial direction of the tube-film obscuring
motion", therefore the more complex the motion, the more effective
the blurring (elimination) of structures outside the focal
plane. The more effective the blur, the less the image will
contain unwanted structures and artifacts that might interfere
with interpretation.
The Panorex CMT PLUS uses the most sophisticated of complex
motions available on the market today, called "hypocycloidal
motion". For details on this technology (as compared to linear/transverse
motion), please refer to Science Behind the Panorex CMT PLUS.
