2. Fluoro 2 Flashcards
During digital fluoroscopy, the time required for the x-ray tube to turn on and reach the mA and kVp selected is called the:
Duty time
Stabilization time
Extinction time
Interrogation time
Interrogation time
Reducing noise and image file size by combining up to four pixels during fluoroscopic image processing is accomplished through:
vignetting
flux gain
pixel binning
pause and pulse
pixel binning
Federal law requires that under normal operation, the Entrance Skin Dose (dose at table-top) rate shall not exceed ______________ for conventional fluoroscopic procedures.
3 R/min
10 R/min
5 R/min
20 R/min
10 R/min
Digital fluoroscopy with a CCD has lower ____________ and higher ____________when compared to image intensified fluoroscopy with a television camera positioned at the output phosphor.
Spatial resolution, maintenance
Patient dose, DQE
Contrast resolution, patient dose
Light sensitivity, patient dose
Patient dose, DQE
Digital fluoroscopy created by a flat panel image receptor (FPIR), also called a flat panel detector:
Increases the radiation dose to the patient during magnification mode
Uses pulse progressive fluoroscopic technology
Operates in fluoroscopic mode, with less than 5 mA
Has a higher patient dose when compared to image intensified fluoroscopy
Uses pulse progressive fluoroscopic technology
The advantage of flat-panel image receptors over image intensifiers in digital fluoroscopy include:
Low SNR
High DQE
Affected by external magnetic fields
Circular imaging area
High DQE
During digital fluoroscopy, the tube is protected from heat overload due to:
High DQE
Low mA
Pulse-progressive fluoroscopy
Continuous fluoroscopy
Pulse-progressive fluoroscopy
At all radiation levels in fluoroscopy, which device maintains a high DQE (detective quantum efficiency)?
Flat panel image receptor (FPIR)
Cathode ray tube (CRT)
Image intensifier with television camera
Image intensifier with charge-coupled device (CCD)
Flat panel image receptor (FPIR)
During Fluoroscopy, the SOD on a fixed unit cannot be less than ______________ inches.
12 in (30 cm)
40 in (100 cm)
20 in (50 cm)
15 in (38 cm)
15 in (38 cm)
A charged coupled device used in digital fluoroscopy:
Replaces the image intensifier in conventional units
Provides low spatial resolution
Replaces the television camera tube in image intensified units
Has a low detective quantum efficiency (DQE)
Replaces the television camera tube in image intensified units
Digital fluoroscopy with a charge-coupled device has lower ______________ and higher ___________than image intensfied fluoroscopy with the television camera at the output phosphor.
Light sensitivity, patient dose
Detective quantum efficiency, maintenance
Patient dose, light sensitivity
Signal-to-noise ratio, patient dose
Patient dose, light sensitivity
In pulse-progressive fluoroscopy, the fraction of time that the x-ray tube is energized is called the:
Subtraction time
Interrogation time
Extinction time
Duty cycle
Duty cycle
Most digital fluoroscopic systems are capable of 8-bit processing, or ____ shades of gray.
32
16
64
256
256
With fluoroscopy, federal law requires an audible _____ minute timer that can be reset as many times as necessary to complete a procedure.
15
20
10
5
5
A lead apron of at least ____ mm Pb/eq must be worn by all people (except the patient) present in the fluoroscopic room during an exposure.
.5
.35
.4
.25
.5
With the flat panel image receptor (FPIR), the image captured is:
Ellipsoidal
Square or rectangular
Triangular
Circular
Square or rectangular
With fluoroscopy, strips of lead rubber forming a drape of ____ Pb/eq are positioned between the fluoroscopist and the patient.
.5
.10
.35
.25
.25
Viewing the fluoroscopic digital image during an exam routinely occurs on a ____________, which is rapidly replacing the cathode ray tube (CRT):
Vidicon
CCD
Flat panel image display
Plumbicon
Flat panel image display
The flat panel image receptor (FPIR) is an array of detector elements (DELS) and is composed of pixels made from cesium iodide (CsI) and:
Amorphous silicon
Crystallized Silicon
Zinc Cadmium Sulfide
Antimony compounds
Amorphous silicon
Advantages of using a charge coupled device (CCD) in digital fluoroscopy systems include:
- High spatial resolution
- Increased lag
- Lower patient dose
1 and 3
1 only
2 and 3
1, 2, and 3
1 and 3
In digital fluoroscopy, the x-ray tube operates in radiographic mode using __________ mA.
Hundreds of
Single phase
0.5-5.0
Less than a hundred
Hundreds of
Continuous Fluoro uses low mA (0.5-5.0)
Most digital fluoroscopic units have this feature which simply maintains the last real-time fluoroscopic image on the viewing monitor until it is replaced by the unit being activated again.
last image hold
minification gain
automatic brightness control (ABC)
magnification mode
last image hold
The flat panel detector used in fluoroscopy enables the operator to use magnification mode with _______ in patient dose, whereas the image intensifier used in fluoroscopy enables the operator to use magnification mode with ________ in patient dose.
no increase; an increase
an increase; no increase
no increase; an increase
In digital fluoroscopy, the time it takes for the generator to switch off is referred to as:
Extinction time
Duty cycle
Rest period
Interrogation time
Extinction time
The bucky slot cover must have ___ mm Pb/eq to protect the gonads of the fluoroscopist.
.15
.25
.2
.1
.25
