NMTCB REVIEW CT, EKG & LUNG
QUESTIONS AND ANSWERS 100%
CORRECT
xrays were discovered by - ANSWER-wilhelm roentgen
xray - ANSWER-radiation with characteristics identical to gamma rays but originates in
electron orbitals
how are xrays produced - ANSWER-charged particles strike a nuclei, interact with the
nucleus and either stop or change direction
xray energy depends on - ANSWER-how closely the charged particle passes by the
nucleus
distant nucleus interactions - ANSWER-low energy, little change in velocity
clse nucleus interactions - ANSWER-high energy, big change in velocity
produces most of imaging xrays - ANSWER-close interaction
in close interactions an atom may - ANSWER-lose an inner shell electron and create
characteristic xray emission
characteristic xrays have - ANSWER-specific energies based on their targets atomic
number
xray tube - ANSWER-rotates around pt to create images
xray tube contains - ANSWER-2 electrodes, cathode and anode
cathode - ANSWER-filament
anode - ANSWER-tungsten
generator creates - ANSWER-current o reach high temps and release outer shell e
generator provides - ANSWER-kvp to pull e from filament to target
tube current or mas - ANSWER-number of electrons moving from cathode to anode per
second
, mas and kvp - ANSWER-effect the number of xrays created
xray tube is kept - ANSWER-under a vacuum to provide a clear path for electrons
long filament - ANSWER-high mas
short filament - ANSWER-low mas, smaller focal point on target
smaller focal point on target - ANSWER-better spatial res
cooling system - ANSWER-anode target rotation to dissipate heat
target and filament are made of - ANSWER-tungsten
gantry houses - ANSWER-tube, generator, filters, colls, detectors
bremsstrahlung are - ANSWER-polyenergetic
lowest kvp photons - ANSWER-not diagnostic, absorbed by tissue, inc rad dose to pt
low kvp are filtered out by - ANSWER-aluminum at tube window
window - ANSWER-only part of tube that lets xrays pass
additional ct filters - ANSWER-thin aluminum or copper sheets that attenuate low
energy xrays
ADC job - ANSWER-amplify and digitize elec signals from detectors
DAS - ANSWER-data acquisition system
DAS parts - ANSWER-detector, ADC, transmissor
fxns of DAS - ANSWER-measure beam, change elec signal to digital, send data to
computer
CT image recon - ANSWER-# rays going to pt v # rays passing through pt
high quality CT - ANSWER-diagnostic CT
low dose ct use - ANSWER-AC, anatomical mapping
when is ac ct done - ANSWER-before pet imaging
order of pet ct - ANSWER-topogram, ct, pet
QUESTIONS AND ANSWERS 100%
CORRECT
xrays were discovered by - ANSWER-wilhelm roentgen
xray - ANSWER-radiation with characteristics identical to gamma rays but originates in
electron orbitals
how are xrays produced - ANSWER-charged particles strike a nuclei, interact with the
nucleus and either stop or change direction
xray energy depends on - ANSWER-how closely the charged particle passes by the
nucleus
distant nucleus interactions - ANSWER-low energy, little change in velocity
clse nucleus interactions - ANSWER-high energy, big change in velocity
produces most of imaging xrays - ANSWER-close interaction
in close interactions an atom may - ANSWER-lose an inner shell electron and create
characteristic xray emission
characteristic xrays have - ANSWER-specific energies based on their targets atomic
number
xray tube - ANSWER-rotates around pt to create images
xray tube contains - ANSWER-2 electrodes, cathode and anode
cathode - ANSWER-filament
anode - ANSWER-tungsten
generator creates - ANSWER-current o reach high temps and release outer shell e
generator provides - ANSWER-kvp to pull e from filament to target
tube current or mas - ANSWER-number of electrons moving from cathode to anode per
second
, mas and kvp - ANSWER-effect the number of xrays created
xray tube is kept - ANSWER-under a vacuum to provide a clear path for electrons
long filament - ANSWER-high mas
short filament - ANSWER-low mas, smaller focal point on target
smaller focal point on target - ANSWER-better spatial res
cooling system - ANSWER-anode target rotation to dissipate heat
target and filament are made of - ANSWER-tungsten
gantry houses - ANSWER-tube, generator, filters, colls, detectors
bremsstrahlung are - ANSWER-polyenergetic
lowest kvp photons - ANSWER-not diagnostic, absorbed by tissue, inc rad dose to pt
low kvp are filtered out by - ANSWER-aluminum at tube window
window - ANSWER-only part of tube that lets xrays pass
additional ct filters - ANSWER-thin aluminum or copper sheets that attenuate low
energy xrays
ADC job - ANSWER-amplify and digitize elec signals from detectors
DAS - ANSWER-data acquisition system
DAS parts - ANSWER-detector, ADC, transmissor
fxns of DAS - ANSWER-measure beam, change elec signal to digital, send data to
computer
CT image recon - ANSWER-# rays going to pt v # rays passing through pt
high quality CT - ANSWER-diagnostic CT
low dose ct use - ANSWER-AC, anatomical mapping
when is ac ct done - ANSWER-before pet imaging
order of pet ct - ANSWER-topogram, ct, pet
