Scan Acquisition And User Interface Basics - GE Revolution CT User Manual

1.1 Scan acquisition and user interface basics

Table 1: Scan acquisition and user interface terms
Generic description
The portion of the user interface where scans are prescribed
Other portions of the user interface, such as where reconstructed
images are viewed
CT localizer radiograph (i.e. the scanned projection radiograph, of‐
ten acquired by the CT system to allow the user to prescribe the
start and end locations of the scan range)
Axial scan mode: Data acquisition while the patient table remains
stationary; the table position may be incremented between X-ray
exposures to collect data over a longer z axis range.
Helical or Spiral scan mode: Data acquisition while the patient ta‐
ble is continuously moving along the z axis.
Dynamic scan mode - single detector width: Data acquisition at
multiple time points over the same anatomic location(s) while the
patient table remains stationary; X-ray exposure can be continuous
or intermittent
Dynamic scan mode - multiple detector widths: Data acquisition at
multiple time points over the same anatomic location(s) while the
patient table cycles back and forth between designated start and
end locations in order image a region wider than the detector
Interventional CT - Intermittent X-ray exposures
Interventional CT - Continuous X-ray exposures
Table increment (mm) per 360 degree rotation of the X-ray tube
(axial scan mode)
Table feed per 360 degree rotation of the X-ray tube (helical scan
mode)
Field of measurement: Diameter of the circular region within the
scan plane over which projection data are collected. Nominally
equal to the diameter of the primary beam at isocenter in the axial
plane.
Tube current: Number of electrons accelerated across an X-ray
tube per unit time, expressed in units of milliampere (mA)
Tube current-time product: The product of tube current and expo‐
sure time per rotation, expressed in units of milliampere • seconds
(mAs). In axial scan mode, this is equal to tube current × (scan an‐
gle ÷ 360) × rotation time. In helical scan mode, this is equal to
tube current × rotation time.
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Revolution CT User Manual
Direction 5480385-1EN, Revision 1
GE names
Scan Settings
Patient tabs or File Man‐
ager
Scout
Axial
Helical
Cine or zero interval Axial
Not used on this system
Not used on this system
Not used on this system
Scan Interval
Speed (mm/rot)
Scan Field of View (SFOV,
cm)
mA
Shown as read only in the
mA mode menu under Re‐
lated Settings
1 Lexicon