Geometric Considerations

 

Terms to know:

Source - The source is in reference to the x-ray tube.  Specifically, it  is the target within the tube when describing distances.

Image Receptor - The image receptor is the part of the system which accepts  the x-rays to convert to an image.  I can be the digital plate permanently  within the table or wall bucky.  It can be a computed radiography plate  within the bucky or on the table top.  It can be a film cassette within the  bucky or on the table top.

Bucky - The image holder within the table or wall mounted system.

Object - Refers to the body part being imaged.

SID - Source to Image receptor Distance. 

SOD - Source to Object Distance.

OID - Object to Image receptor Distance.

Central Ray - Refers to the primary beam, specifically the exact center of  the primary beam

Distortion - There are 2 types.  Size distortion, and shape distortion.

Size distortion - Magnification.  When the size of the object being  imaged is not truly represented in size.

Shape distortion - there are 2 types of shape distortion.  The result of  the shape distortion depends on how the image receptor, object, and central ray  are positioned.

SIDOID