Help
Options
Didn't know it?
click below
click below
Knew it?
click below
click below
Don't Know
Remaining cards (0)
Know
retry
shuffle
restart
0:00
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.
Normal Size Small Size show me how
Normal Size Small Size show me how
RADT 412 QC
Quality Control
| Question | Answer |
|---|---|
| QC deals with _______ | EQUIPMENT Routine checks reduces need for maintenance |
| QA deals with _______ | PEOPLE How techs are performing |
| CQI (Continuous Quality Improvement) | Combination of both QA & QC; ensures quality patient care is being given! (Regulated by government) |
| 3 parts of QC Program | *Checks overall quality of equipment 1) Visual inspection 2) Environmental Inspection 3) Performance Testing |
| Visual Inspections should happen ______ | DAILY |
| Visual Inspection checks (list 5) | 1. Control panel 2. Overhead tube crane (no exposed wires, broken ties, etc) 3. Table 4. Lead aprons/shields (check aprons when new then every 6 months) 5. Ancillary equipment: sponges, calipers, filters, grids, etc. |
| Environmental Inspections checks ______ | High tension cables (visible wires for fraying, discoloration, sparking) Room temperature (equipment can get too hot) |
| Performance testing levels include | - Acceptance testing - Baseline performance parameters: est. baseline 1 or 2 months of use - Preventative maintenance & Routine testing: service engineer/medical physicist; checks after major component replaced - Daily, weekly, monthly checks |
| Exposure (mA) Linearity | Definition: accuracy of mA station relative to another used ANNUAL + or - 10% of adjacent station *Least reliable technique factor |
| Exposure Reproducibility | Definition: ability of equipment to repeat the same overall technique settings to get same results in exposure + or - 5% ANNUAL |
| filtration & Half Value Layer (HVL) | Definition: thickness of absorber material required to reduce the intensity of the xray beam to 1/2 its original value ANNUAL |
| HVL is the most _________ and the most ________ quality | accurate measurement of beam penetration; important |
| High HVL = _________ penetrating beam | HIGH |
| kVp Accuracy | use kVp meter, ion chambers/photodiodes ANNUAL + or - 5% |
| Timer Accuracy | Measures accuracy of exposure timer selected ANNUAL + or - 5% |
| Beam Alignment | Checks the crosshairs of collimator light using metal screw & BB SEMI-ANNUAL + or - 2 degrees off vertical |
| Collimator Accuracy | Checks projected xray field vs. the actual xray field (penny test) SEMI-ANNUAL + or - 2% of SID (0.8") |
| Distance | Measure SID to see if indicator reads the same SEMI-ANNUAL + or - 2% of SID |
| Focal Spot Size & Condition | Checks for last resolved line pair (LP/mm) ANNUALLY + or - 50% of stated size of focal spot |
| AEC | Looking for repeatability; making sure back up timer shuts off when it should ANNUAL + or - 10% same unit |
| IR calibration is done ______ | daily |
| IR maintenance is done _________ | semi-annual |
| IR tests done for (list 4) | Intrinsic (dark noise) Erasure thoroughness Plate/ Field Uniformity Spatial Resolution |
| Intrinsic (dark noise) comes from ___________ ___________ so we must erase CR detectors every _________ | background radiation; 48 hours |
| Erasure thoroughness is known as | Ghosting or Image Lag |
| Determine ghosting with | 2 exposures (1 with high attenuator object 1 without object) |
| Plate / Field Uniformity | Use long SID (don't change contrast) and check similarity of contrast boxes DAILY or SEMI-ANNUALLY |
| Spatial Resolution | Uses wire mesh, line pair took, or digital test test should look uniform in shade and crosses |
| KNOW TABLE 37.1 | :) so sorry |
| 3 main parts of the fluoro unit | 1. x-ray tube 2. generator 3. image intensifier (I.I.) |
| Image intensifier parts | Glass envelope (vacuum), input phosphor, photocathode, electrostatic focusing lenses, anode, output screen/phosphor |
| Minification Gain | input diameter squared / output diameter squared |
| Flux Gain "Flow" | Acceleration of electrons increases kinetic energy so more light is released |
| Brightness Gain | minification gain x flux gain |
| Image is magnified in an I.I by _________ | moving the focal point closer to input phosphor |
| Unique feature of fluoroscopy = meter that detects _______ | Air Kerma/ DAP meters or the radiation interactions occurring in the air when x-rays sent toward patient |
| 2 examples of phantom tests | Spatial resolution & uniformity AND contrast linearity |
| Exposure rate (fluoro) should not exceed _________ | 100 mGy/min or 10R/min |
| _______ kVp and ______ mA is desired | High; low |
| Source-to-skin distance (SSD) needs to be ________ for mobile c-arm | 12 inches |
| SSD needs to be ______ for standard stationary/fixed | 15 inches |
| Collimator Accuracy (fluoro) | shutters should be visible on monitor field within 4% of SID |
| Visible/Audible Monitors for fluoro exposure time | Cumulative timer: every 5 min Visible indicator: beam on light |
| Automatic Brightness Systems (ABS) are used to _________ | maintain a constant image brightness |
| The exposure switch is a _________ switch, meaning if exposure button is released, then it will stop | Deadman switch aka if you die, the exposure will stop x.x |
| Veiling Glare | light reflected "glare" shows up white |
| Pincushion distortion | input phosphor curve compared to flat output phosphor shape creates distortion around periphery |
| Barrel distortion | opposite to pincushion (looks like barrel) |
| Vignette | lateral borders are darker |
| S-distortion | strong magnetic field creating s-shape distortion |
| Protective Apparel QC checked | ANNUALLY Includes lead gloves, aprons, and protective curtains |
| Primary Display Devices are used by _________ | radiologists! Interpretation & diagnosis larger matrix and smaller pixel size |
| Secondary Display Devices are used by ______ | technologists/PACS used for everything else |
| Interpolation definition | mapping of image of one matrix to a display of another size; ex. small artifacts to a tech can look HUGE to a radiologist monitor |
| Aspect ratio definition | ratio of width to height of display |
| Refresh rate definition | how many times each second the monitor rewrites the image on the display |
| 2 main types of electronic display devices | 1. Liquid Crystal Diodes (LCD) displays 2. Light emitting diodes (LED) displays |
| Disadvantages of LCDs | viewing angle is best head on (glare), lack of true black color, time/temperature dependency for brightness |
| LEDs are | NOT used in radiologic imaging |
| QC of electronic display devices | clean front screen MONTHLY |
| Luminance definition | intensity of light emitted |
| Resolution definition | ability to differentiate between things |
| Grayscale standard display function (GSDF) | use photometer to check consistency/intensity of gray scale appearance on screen regardless of monitor device |
| Dead Pixels appear as _____ | a dot! 12 pt font will appear as a white spot on black background |
| Stuck pixels appear as ____ | a black dot on a white background it is any signal not refreshed or "stuck" from previous image |
| QC benefits (list them) | Patient Safety (#1 benefit! All about the pt) Reduced radiation Exposure Efficacy of Patient care Departmental efficiency Consistent image quality Cost-effectiveness |
Created by:
SavHoffman25
Popular Radiology sets