Tomography Flashcards
What types of exams use tomography?
- IVP
- TMJ
- Mandible (panorex)
What is tomography
special technique used to improve visualization of selected objects by blurring out other structures in the body
What is the principal advantage of tomography
Contrast resolution
Where do the X-ray tube and the IR pivot at?
at the fulcrum
What does the location of the fulcrum define and control?
Defines object plane or focal plane
-Controls: Section level
How is the fulcrum adjusted
depending on object plane of interest in mm or cm (cuts)
Term for Thickness of tissue to be imaged?
and what controls the thickness
Tomographic section
-Controlled by tomographic angle
Term for factor that determines the thickness of the part to be imaged.
Tomographic angle
The further from the object plane an anatomical structure is , the more ____ its image will be
Blurred
The larger the tomographic angle the __ the tomographic section will be
thinner
What type of grid must be used in tomography and why?
// grids because grid line must be in the same direction as the tube movement
-Structures below or above the object plane appear
Blurred
Structures within the object plane appear?
Sharp
The position of the object plane is defined by the location of the ?
Fulcrum
-It is changed by changing the fulcrum
Name factors that influence image blurring
- Distance of object from objective plane
(As object gets further from objective plane,= more blurring)
2.Exposure angle
(if angle increases,blurring increases)
3.OID
(as OID increases, blur increases) - Alignment of anatomic part in relation to tube movement
(anatomy should be perpendicular to tube to maximize blurring outside objective plane)
5.Sectional thickness
(more blurring= thinner the objective plane)
