CT review

primary mathematical method used in the creation of computerized medical images is

Fourier transformation

a series of tissue density values that evolved for CT measurements is called what?

Hounsfield units

as noise increases in a CT image

a low contrast resolution increases

in the event a CT pt. needs emotional support for a procedure during the acquisition

a pt. family member should be allows to attend to the pt.

calculation of CT numbers is based upon the calculations of

attenuation coefficients

the smaller the scan field size the

better resolution faster scan time less the risk of motion

process of modifying pixel values by a mathematical formula

convolution

computed tomography sections are available as

coronal, sagittal and transverse

increasing FOV does what to resolution

decreases

the most recent generation of CT scanners use what motion

helical

What does kVp, slice thickness and pitch do to pt. dose

i

increasing magnification does what to resolution

increases

What does increasing kVp, slice thickness, dose reduction, distance from tube to isocenter, shielding and pitch do to pt. dose

it decreases it

what does increasing mA, exposure time, pt. size, do to pt. dose

it increases it

A CT radiographer usually varies what to control the primary beam

mA

to achieve coronal and sagittal sections what has to happen

reconfiguration software is implemented

artifact is caused by detector error

ring

the localization image produced by the CT scanner is technically called what

scanogram

CT console provides the radiographer access to what?

software program data acquisition data display

what artifact is caused by presence of metal in the pt.

star

first generation CT scanners scanned only the what?

the head

CT image data is acquired in the

transverse plane and reconstructed in any plane

the gantry of the CT unit contains what?

xray tube