Ch.20 Anode Bevel And Focal Spot Flashcards
At a bevel angle of 17 degrees describe the relationship between the size of the actual focal spot and the effective focal spot.
The effective focal spot is smaller than the actual focal spot.
At a bevel angle of 45 degrees describe the relationship between the size of the actual focal spot and the effective focal spot.
They are the same size
What is the actual focal spot?
The area on the beveled anode surface
What is the effective focal spot?
The area projected onto the patient and IR.
If you choose the large focal spot on the control panel what size is the focal spot?
Projected focal spot is 1-2mm
If you choose the small focal spot on the control panel what size is the focal spot?
Projected focal spot is .5-1mm
Describe the anode heel effect.
It is a variation of X-ray intensity from cathode to anode. With the intensity diminishing rapidly from cathode to anode
The anode heel acts and a type of ____ filtration.
Inherent
Photons exiting ___ to the anode have less distance to travel than those toward the heel.
Perpendicular
As you go from cathode to anode the photons have more and more ___ to pass through before it can exit the tube.
Filtration
If the anode angle is 17 degrees is there more or less anode effect?
More because they have a longer path through the target which increases absorption
If the anode angle is 45 degrees is the anode effect more or less?
Less
What does focal spot effect on the image?
Sharpness
The smaller the focal spot the ___ the recorded detail.
Sharper
Focal spot is ____ proportional to the image sharpness.
Inversely
