Biomedical Imaging X-ray5

Is CT contrast resolution better or worse than xray imaging?

Better
Is CT spatial resolution better or worse than Xray imaging?

Worse
What are all the CT artefacts
- Beam hardening
- Ring artefacts
- Aliasing
- Partial volume effects
- Motion artefacts
What causes aliasing and what does it look like on CT
- Insufficient sampling or tube current
- Looks like dark lines radating around dense object
What is partial volume effect and what does it look like in CT
- Occurs with object smaller than slice thickness or at slice edges
- Attenuation coefficients are averaged out
Results in blurring
What is motion artefacts and what does it look like
- When patient moves
- Results in blurring
What are ring artefacts in CT caused by?

Caused by detector fault
What does a Beam hardening artefact look like

Centre of image looks brighter.
What is mA modulation in CT
- Required in CT to ensure that a sufficient no of xrays reach the detector
- Patients are ont the same thickness head to toe so need different mA
- mA modulation aims to keep detector dose constant by reducing mA through thinner part of patient.
What is pitch in CT scanners. What is another name for it

table movement per 360 roation/detector weidth
What iscollimator pitch

table movement per 360 roation/collimator width

Author

keesukim

340202

Card Set

Biomedical Imaging X-ray5

Description

(INCOMPLETE) CT and helical and axial stuff

Updated

2018-05-14T10:15:58Z

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