QUIZ #2 Flashcards
[Collimator testing quarterly]
[_____]
[_____]
[_____]
[_____]
[Collimator Testing quarterly]
Light field - x ray field congruency
Image receptor (PBL) - x ray field congruency
Accuracy of X/Y scale
Illuminator bulb brightness
[Collimator testing semi-annually]
[_____]
[_____]
[Collimator testing semi-annually]
All AEC
Overload heat warning
[Light field- X ray field Congruency]
The [_____] of the light field to the radiation field is of great importance.
It must be within +/- [__] of the SID used
This is AKA the [_____] test
Film is placed table top and collimation is done, two pennies are lined up, so that they touch exactly where the light field ends. On all 4 sides.
Exposure is made and inaccuracies are totaled.
[Light field- X ray field Congruency]
The accuracy of the light field to the radiation field is of great importance.
It must be within +/- 2% of the SID used
This is AKA the 9 penny test
Film is placed table top and collimation is done, two pennies are lined up, so that they touch exactly where the light field ends. On all 4 sides.
Exposure is made and inaccuracies are totaled.
[Image receptor / X ray field Alignment]
Assures that the x-ray field is accurate to the size of a film when using [_____].
An unloaded 8X10 cassette is placed in bucky. A loaded 10 X 12 cassette is table top.
All are centered to the tube at 40” SID. Expose
If the resulting field size is 8 X 10 or less this passes, if it is more, triangulation is required to determine actual size. +/- [__] total, +/- [__] one side.
[Image receptor / X ray field Alignment]
Assures that the x-ray field is accurate to the size of a film when using PBL.
An unloaded 8X10 cassette is placed in bucky. A loaded 10 X 12 cassette is table top.
All are centered to the tube at 40” SID. Expose
If the resulting field size is 8 X 10 or less this passes, if it is more, triangulation is required to determine actual size. +/- 4% total, +/- 3% one side.
[Central Ray Congruency]
Ensures that center of [_____] is aligned with central ray.
Place loaded 8 X 10 cassette in tray, center tube at 40 “ SID, collimate to 4 X 6 area.
Expose
Draw line from corner to corner of film. Repeat from opposite corner. Place dot where lines intersect. Repeat for irradiated area.
Measure distance between points. Must not exceed +/- [__].
[Central Ray Congruency]
Ensures that center of bucky tray is aligned with central ray.
Place loaded 8 X 10 cassette in tray, center tube at 40 “ SID, collimate to 4 X 6 area.
Expose
Draw line from corner to corner of film. Repeat from opposite corner. Place dot where lines intersect. Repeat for irradiated area.
Measure distance between points. Must not exceed +/-1 % SID.
X/Y Scale- +/- [__]
Bulb Brightness- Using a photometer the illumination should be [__] ft-c or [__] lux at 40” SID.
SID indicators- +/- [__]
Overload Protection- Prevents exposure that exceeds [__] % of potential.
Heat Sensors- provides warning when [__] % capacity is reached.
X/Y Scale- +/- 2% SID
Bulb Brightness- Using a photometer the illumination should be 15 ft-c or 160 lux at 40” SID.
SID indicators- +/- 2% SID
Overload Protection- Prevents exposure that exceeds 80% of potential.
Heat Sensors- provides warning when 75% capacity is reached.
[Beam Alignment]
Ensures that the tube is mounted properly in housing, preventing any [_____].
The tube must be mounted within [__]-degree of perpendicular.
Testing should be done [_____].
A specific test tool is used to determine.
[Beam Alignment]
Ensures that the tube is mounted properly in housing, preventing any distortion.
The tube must be mounted within 1 degree of perpendicular.
Testing should be done annually.
A specific test tool is used to determine.
[Automatic Exposure Control (AEC)]
Advantage is consistent OD over range of [_____].
Uses a set intensity, once reached in detector, circuit is turned off
Density steps will increase/decrease set point changing intensity set point (mAs) only.
Back up timers are required to prevent excessive exposure to patient and tube, [__] sec or [__] mAs.
[Automatic Exposure Control (AEC)]
Advantage is consistent OD over range of patient size.
Uses a set intensity, once reached in detector, circuit is turned off
Density steps will increase/decrease set point changing intensity set point (mAs) only.
Back up timers are required to prevent excessive exposure to patient and tube, 6 sec or 600mAs.
[AEC Consistency Testing-mA]
AEC should adjust [_____] to maintain OD with different mA stations
+/- [__] %
+/- [__] OD
Center tube to bucky and phantom at 40” SID
Place 10 X 12 in bucky and expose, repeat four times, using different mA stations
Process and measure OD at center
[AEC Consistency Testing-mA]
AEC should adjust time to maintain OD with different mA stations
+/- 10 %
+/- 0.2 OD
Center tube to bucky and phantom at 40” SID
Place 10 X 12 in bucky and expose, repeat four times, using different mA stations
Process and measure OD at center
[AEC Consistency Testing-kVp]
AEC should adjust [_____] to maintain OD with different kVp settings.
+/- [__] %
+/- [__] OD
Center tube to bucky and phantom at 40” SID
Place 10 X 12 in bucky and expose, repeat four times, using 100 mA station and kVp settings of 60, 70, 80, 90.
Process and measure OD at center
[AEC Consistency Testing-kVp]
AEC should adjust time to maintain OD with different kVp settings.
+/- 15 %
+/- 0.3 OD
Center tube to bucky and phantom at 40” SID
Place 10 X 12 in bucky and expose, repeat four times, using 100 mA station and kVp settings of 60, 70, 80, 90.
Process and measure OD at center
[AEC Consistency Testing-Part Thickness]
AEC should adjust [_____] to maintain OD with different part thicknesses.
+/- [__] %
+/- [__] OD
Center tube to bucky + phantom at 40” SID
Place 10 X 12 in bucky and expose three times with an 100 mA station, adding a layer of material so images are taken with 10, 20 + 30cm of acrylic.
Process and measure OD at center
[AEC Consistency Testing-Part Thickness]
AEC should adjust time to maintain OD with different part thicknesses.
+/- 10 %
+/- 0.2 OD
Center tube to bucky + phantom at 40” SID
Place 10 X 12 in bucky and expose three times with an 100 mA station, adding a layer of material so images are taken with 10, 20 + 30cm of acrylic.
Process and measure OD at center
[AEC Consistency Testing-Field Size]
AEC should adjust [_____] to maintain OD with different areas of collimation
+/- [__] %
+/- [__] OD
Center tube to bucky and phantom at 40” SID
Place a film in bucky taking three exposures at 100 mA an collimation of 6 X 6, 10 X 10 and 14 X 14
Process and measure OD at center
[AEC Consistency Testing-Field Size]
AEC should adjust time to maintain OD with different areas of collimation
+/- 5 %
+/- 0.1 OD
Center tube to bucky and phantom at 40” SID
Place a film in bucky taking three exposures at 100 mA an collimation of 6 X 6, 10 X 10 and 14 X 14
Process and measure OD at center
[AEC Consistency Testing-Detector]
AEC should adjust [_____] to maintain OD with different detector configurations
+/- [__] %
+/- [__] OD
Center tube to bucky and phantom at 40” SID, 100mA and 70 kVp
Place 14 X 17 in bucky and expose three times using each detector
Process and measure OD at center
[AEC Consistency Testing-Detector]
AEC should adjust time to maintain OD with different detector configurations
+/- 10 %
+/- 0.2 OD
Center tube to bucky and phantom at 40” SID, 100mA and 70 kVp
Place 14 X 17 in bucky and expose three times using each detector
Process and measure OD at center
[AEC Reproducibility]
AEC should maintain OD when the same [_____] and [_____] are used
+/- [__] %
+/- [__] OD
Center tube to bucky and phantom at 40” SID
Place 10 X 12 in bucky and expose three times, using80 kVp at 200mA.
Process and measure OD at center
May also be done with a meter (mR), +/- 0.05 variance
[AEC Reproducibility]
AEC should maintain OD when the same mA and kVp are used
+/- 5 %
+/- 0.1 OD
Center tube to bucky and phantom at 40” SID
Place 10 X 12 in bucky and expose three times, using80 kVp at 200mA.
Process and measure OD at center
May also be done with a meter (mR), +/- 0.05 variance
[Back up Timer]
Back up or maximum exposure limits should be set at [__] mAs or [__] seconds
This will prevent over exposure to patients and damage to the tube.
[Back up Timer]
Back up or maximum exposure limits should be set at 600mAs or 6 seconds
This will prevent over exposure to patients and damage to the tube.