Question | Answer |
refers to the sharpness of structural lines recorded in the radiographic image | geometric properties |
Optimal geometric quality is achieved by maximizing the amount of ________ and minimizing the amount of ________. | maximizing recorded detail and minimizing image distortion |
refers to the distinctness or sharpness of the structural lines that make up the recorded image | recorded detail |
What alters the amount of unsharpness recorded in an image? | the size of the focal spot, SID, and OID |
Focal spot size is determined by: | the filament size |
What is a typical small focal spot size? | 0.5 or 0.6 mm |
What is a typical large focal spot size? | 1.0 or 1.2 mm |
What does focal spot size affect? | recorded detail |
True or False: The focal spot size affects recorded detail and can change as an z-ray tube ages. | True |
What relationship does focal spot size have with recorded detail? | inverse |
When the SID is increased, the amount of image unsharpness is ____. | decreased |
When the SID is increased, the amount of recorded detail in the image ________. | increases |
Except for chest and cervical spine radiography, what is the standard SID? | 40" or 48" (100cm or 122cm) |
SID indicators should be accurate within ___% of the SID. | 2% |
Optimal recorded detail is achieved when the OID is ______. | zero |
When the OID is increased, the amount of unsharpness _______. | increases |
When the OID is increased, the recorded detail ________. | decreases |
What has the greatest effect on the amount of geometric unsharpness recorded? | OID |
When increased OID is unavoidable, SID should be ________ slightly to compensate. | increased |
refers to the smallest detail that can be detected in an image | spatial resolution |
refers to images of objects that appear longer than the true objects | elongation |
refers to images that appear shorter than the true objects | foreshortening |
unsharpness resulting from patient motion | blur |
Why can't a radiographic image be an exact reconstruction of the anatomic structure? | Because some information is always lost during the process of image formation |
Why can't a radiographic image be an exact reconstruction of the anatomic structure? | Because some information is always lost during the process of image formation |