Complete Solutions.
the measurement of the attenuation that occurs along each path through the patient from the xray
tube to the detector correct answers data acquisition
the computerized processing of the transmission measurements into the ct image correct answers
data reconstruction
display of the reconstructed grayscale image in 2D and/or 3D format, a representation of the
attenuation that occurred across the scanned volume of tissue correct answers multidimensional
image display
display as well as storage, both short term and long term archival of images on workstations
correct answers image archival and communication
The angle of the tube and detectors in relationship to the patient position during scout acquisition
correct answers azimuth
the technixal elements of helical ct acquisition include: (4) correct answers -continuous rotation
of the gantry (slip ring technology)
-a powerful xray tube capable of long exposure times
-continuous movement of the table
-specialized mathematical reconstruction techniques
the development of ____ advanced the helical acquisition sequence correct answers
multidetector ct (MDCT)
_____ enables ct sections of varying widths to be reconstructed at any point along the acquired
volume correct answers multidetector arrays
____ allows for a choice of two focal spots ranging from .5-1.2 mm in diameter correct answers
dual filaments
normal focal spots for ct range from: correct answers .5-1.3 mm
___ focal spots improve the geometric efficiency of the xray beam, leading to greater spatial
resolution correct answers smaller
____ involves the electromagnetic steering of the electron beam emitted from the cathode.
correct answers flying focal spot
, with flying focal spot technology, the electrons are directed towards two separate locations on
the rotating anode, resulting in: correct answers two sources of radiation
as the tube rotates around the patient, the number of data samples is essentially doubled because
of: correct answers two focal spots
having two focal spots, the oversampling technology will improve ___ and ___ correct answers
temporal and spatial resolution
what are 4 ways that the tube dissapates heat correct answers -oil
-air cooling
-increased anode diameter
-conduction by tube rotation
what are 3 specific characteristics that enable a tube to achieve the performance demanded by
MDCT correct answers -high heat rating
-small and lightweight
-stable and long lasting
____ programs adjust the mA throughout the acquisition to reduce patient radiation dose to a
minimum correct answers automatic tube current modulation
___ alters the applied mA according to a predetermined noise index that is acceptable for
appropriate image quality correct answers automatic tube current modulation
the ___ value directly controls the quantity of xrays, or photon fluence, directed towards the
patient correct answers mA
the rate at which the photon fluence passes through a unit area over unit time correct answers
photon flux
the mAs value for a given acquisition is ___ proportional to patient radiation dose and ___
proportional to images noise correct answers directly
inversely
the calculated mAs value per acquired slice correct answers effective mAs
the main controlling factor of effective mAs is: correct answers table speed
the ____ selected for a given acquisition determines the speed at which the patient translates
though the gantry for each tube revolution correct answers pitch
what is the effective mAs formula correct answers mAs/pitch
as pitch increases, mAs applied to each acquired slice ______ correct answers decreases