Week 2 Flashcards
Axial scanning is still used today for ___ imaging as it provides better image quality than helical scanning
Brain
The time delay between scans in axial scanning
Interscan delay (ISD)
Scan area of interest set by the technologist
Scan field of view
Reconstructed area seen on the image monitor
Display field of view
volumetric counterpart to pixel
voxel
___ determines the maximum number of shades of gray in the image (image contrast)
window width (WW)
The midpoint of the range of CT numbers; determines displayed image brightness
Window level
___ WL appears brighter; ___ WL appears darker
Low; high
Displays a video-like format; obtained through overlapping image sets
Cine
When considering detector efficiency, the measure of how well the detectors gather incoming photons is called:
Capture efficiency
When considering detector efficiency, the measure of how well captured photons are absorbed and converted to electrical signals is called:
absorption efficiency
In multidetector CT systems, __________ determine(s) slice thickness.
reconstruction algorithms
When considering detector efficiency, the measure of how consistently the detectors respond to similar transmitted radiation events is called:
reproducibility
In single slice CT scanning, thin collimation results in [increased/decreased] resolution
increased
The development of helical and continuous acquisition scanning was made possible by:
slip-ring technology
