Computed Tomography

Which type of CT is worse at soft tissue lesions

Cone beam CT

Like radiographs CT has how many opacities?

5

What are the opacities for CT

• gas

• fat

• soft tissue

• mineral

• metal

What are the planes of CT

• sagittal

• transverse

• dorsal

If you wish to apply an algorithm to a CT you must be done _______ the scan

before

what type of algorithms are available for CT

• sharp

• soft

if you wish to change the displays you are able to do it _________

retroactively

Why is volume acquisition so useful

• elimination of superimposition

• better resolution of small structures

• better tissue contrast

• intravenous contrast medium for enhancement

What body parts is it useful to use a CT

• skulls

• nasal

• ears

What small structures is CT the preferred use

• vascular anomalies

• pancreatitis

• elbows

What slice thickens should the CT be set for

0.5-1.5 mm

What pitch is ideal for CT

1

The overlap in the spiral of the CT is known as ___________

pitch

Window width tell you what?

tell you how many grays you have

a smaller window width allows for _________ to be picked up

subtle changes

Window level tells you what?

tells you where on the scale your opacity starts

The contrast/grays of a CT are described in what terms?

Hounsfield units

What are common artifacts to identify on CT

• photon starvation/Beam hardening

• quantum mottle

• patient motion

What is most likely in CT to have photon starvation/beam hardening

• metal transponder

• temporal bone

What could cause quantum mottle/noise artifact in CT

not enough MA

How would you fix quantum mottle

• increase MA