CT Parameters Trade Off Sheet Flashcards
What are the Effects of Increasing kVp (5)
Contrast. May be increased or decreased
Resolution Unchanged
Apparent Noise Decreases
Dose Slightly Increases
In Conclusion:
Increasing the penetration of photons for larger patients increases the contrast between tissues.
**Please note: Too high kVp results in most of
the photons penetrating through all tissues of the
anatomical tissues being imaged thus
differentiate between structures decrease.
What are the Effects of Increasing mAs (5)
Contrast Unchanged
Resolution Decreases
Apparent Noise Decreases
Dose May Decrease
In Conclusion
Visualization of large structures is improved due
to less noise, but partial voluming is increased.
What are the Effects of Increasing Table Increment (5)
Contrast Unchanged
Resolution May decrease
Apparent Noise Unchanged
Dose Decreases
In Conclusion
Gap between slices are increased which can
result in structure and pathology being missed,
but patient dose is decreased.
what are the Effects of Increasing Pitch (5)
Contrast Unchanged
Resolution May increase effective slice
thickness
Apparent Noise Unchanged
Dose Decreases
In Conclusion
Increases anatomical coverage.
What are the Effects of Increasing Reconstruction Field-of-View (5)
Contrast Unchanged
Resolution Decreases
Apparent Noise Decreases
Dose Unchanged
In Conclusion
\Larger field of view makes the it more difficult to
see tiny object because the displayed detail is
smaller, on the other hand the image appear less
grainy.
What are the Effects of Increasing Image Matrix (5)
Contrast Unchanged
Resolution Increases
Apparent Noise Increasing
Dose Unchanged
In Conclusion
Results in smaller pixels therfore smaller
structures can be resolved.
What are the Effects of Using a Sharper Reconstruction Filter (4)
Resolution Increases
Apparent Noise Increases
Dose Unchanged
In Conclusion
By emphasizing the high contrast borders, some
of the lower contrast structures may not be
clearly seen. Additionally, the image will appear
grainy.
