RAD 211: Unit 5 Quality Assurance, Control & Testing

What is the formula for the inverse square law?

Intensity (old) / intensity (new) = distance (new) ^2 / distance (old)^2

What are the benefits of a QC/QM program for department?

Monetary savings by reduced repeat rate (film, labor, equipment depreciation)

What needs to be checked on digital/video display monitors?

check spatial resolution, optical density/brightness with phantom image quality test tool.

What does CQI stand for?

continuous quality improvement

Effective quality control and quality assurance programs are required for accreditation by:

the Joint Commission

What is half-value layer?

the amount of filtration causing the beam to be reduced by 50% when compared to having no Al in the beam

What is quality control?

the aspect of QM that monitors technical equipment to maintain quality standards. Deals with equipment

What are some reasons for reject analysis?

makes personnel aware of repeats/rejects, can analyze causes for repeats/rejects, demonstrates cost waste and unnecessary exposure

Exposure linearity must be accurate to within what?

10%

kVp must be accurate to within:

10%

Delivery of large exposures to a cold anode or the use of exposures exceeding tube limitations can result in: I. increased tube output II. cracking of the anode III. rotor-bearing damage

2 and 3 only

The collimator light and the actual irradiated area must be accurate within what percentage of the SID?

2%

The xray beam and collimator light field must coincide to within what?

2% of the SID

If the exposure rate at 2 meters from a source of radiation is 18mR/min, what will be the exposure rate at 5 meters from the source?

2.8 mR/min

How many half value layers will it take to reduce an x-ray beam whose intensity is 78R/min to an intensity of less than 10R/min?

3

What is the normal reject rate?

5 (ideal) to 15%, density and positioning most frequent cause. Difficult to get under 5% due to factors outside tech's control

Exposure reproducibility must be accurate to within what?

5%

If the distance from the focal spot to the center of collimator mirror is 6 inches, what distance should the illumitars bulb be from the center of the mirror

6 inches

How often should CR plates be erased?

Erase 24-48 hours

Continous quality improvement tends to focus on the people or the service rather than the process

False

IEMA

Illinois Emergency Management Agency

What should the collimator test tool be within?

+/- 2%

Using the the timer accuracy tests, if ≤ 10 ms it should be within what?

+/- 20 %

Using the the timer accuracy tests, if > 10 ms it should be within what?

+/- 5 %

The kV setting on radiographic equipment must be tested annually and must be accurate within what?

+/- 5 kV

What should reciprocity be within?

+/- 5%

What should displayed kVp test be?

+/- 5% kVp of the set kVp

Which of the following will improve the spatial resolution of image-intensified images I. a very thin coating of cesium iodide on the input phosphor II. a smaller diameter input screen III. increased total brightness gain

1 and 2 only

A slit camera is used to measure I. focal spot size II. spatial resolution III. PSP resolution

1 only

Deposition of vaporized tungsten on the inner surface of the x-ray glass window I. acts as additional filtration II. results in increased tube output III. results in anode pitting

1 only

What must the central ray congruency or x-ray beam/bucky tray alignment be?

1% of SID

A quality control (QC) program includes checks on which of the following radiographic equipment I. reproducibility II. linearity III. positive beam limitation/automatic collimation

1,2, and 3

Patient dose during fluoroscopy is affected by the I. distance between the patient and the input II. amount of magnification III. tissue density

1,2, and 3

What do the mAs accuracy tests have to be within?

10 %

What is perpendicularity of the beam?

Beam should be within 1 degree of perpendicular

What is the kvp accuracy test

Check penetrating capabilities kV and mA change as tube ages Digital kVp meters are used for this test

Whom is principally responsible for the QC/QA program?

QC technologist

What are the benefits of a QC/QM program for patients?

Reduction in x-ray exposure Reduction in time spent in the department

What can be used to determine if the monitor is displaying any distortion over the display?

SMPTE pattern

SSD

Source-to-skin distance

Acceptance testing should never be done by a _____. a. medical physicist b. manufacturer's representative c. QC technologist d. radiologic engineer

b. manufacturer's representative

TJC

The Joint Commission

The line focus principle refers to the fact that

The actual focal spot is larger than the effective focal spot

What is the formula for reject rate?

Total rejected films/Total film used

How does the mA accuracy tests work?

Use a computerized dosimeter and make 4 exposures using different mA stations

What are timer accuracy tests?

Use computerized dosimeter/digital timer for readout of exposure times (used to be the spinning top test) If > 10 ms, should be within +/- 5 % If ≤ 10 ms, should be within +/- 20 %

What is the penny test?

Used for light field-radiation field congruence Arrange 8 pennies on a cassette so they outline light field. Make exposure. X-ray field must be within 1/2 penny of light field

The determination of how consistently radiologists' image interpretations match patients' ultimate diagnoses is called _____. a. exposure linearity b. outcome analysis c. reproducibility d. uniformity

b. outcome analysis

The collimator must be accurately aligned to within ±_____% of the SID. a. 2 b. 5 c. 10 d. 12

a. 2

A QC program should include _____, routine performance monitoring, and maintenance. a. acceptance testing b. outcome analysis c. calibration d. personnel monitoring

a. acceptance testing

Most quality control testing on radiographic equipment is done _____. a. annually b. semiannually c. monthly d. weekly

a. annually

A minimum total amount of aluminum filtration A (inherent plus added) of 2.5 mm is required in equipment operated above what?

above 70 kVp

Resolution of the television monitor system may be measured using the following tool(s):

all of the answers listed

Effective focal spot size may be measured using the following tool(s):

all of the listed answers

What is done after the instillation of new equipment to determine if the equipment is performing to vendor specifications?

all of the listed answers

Which of the following are daily QC duties of the technologist?

all of the listed answers

Whose responsibility is it to maintain the quality of digital images?

all of the listed answers

Define quality control

all the actions necessary to control and verify the performance of equipment. It is part of quality assurance. It is the part of quality management that monitors technical equipment to maintain quality standards

How often are radiographic kV settings required to be evaluated (minimally acceptable)?

annually

The responsibilities of the medical physicist must be carried out at least how often?

annually

With what frequency must radiographic equipment be checked for linearity and reproducibility (minimal acceptable level)?

annually

A device used to ensure reproducible radiographs, regardless of tissue density variations, is the what?

automatic exposure control

AEC

automatic exposure control

A quality assurance program monitors _____. a. films b. imaging equipment c. people d. processors

c. people

The first step of the QA recommended by the Joint Commission on Accreditation of Healthcare Organizations (JCAHO) is to _____. a. collect and organize data b. take action to improve care c. assign responsibility d. assess and document actions

b. take action to improve care

The source to table distance in fixed/stationary fluoroscopy must

be at least 15 inches

All general purpose radiographic units must have a minimum of _____ mm Al filtration. a. 1.5 b. 2.0 c. 2.5 d. 3.0

c. 2.5

A quality control program is for _____. a. film processors b. CT scanners c. x-ray tubes d. all of the above

d. all of the above

Medical facilities have quality control programs in place in order to _____. a. have JAHCO approval and accreditation b. ensure quality patient care c. receive payment from insurance carriers d. do all of the above

d. do all of the above

Filtration is measured with _____ measurements. a. caliper b. photometer c. slit camera d. half-value layer

d. half-value layer

The test that measures the accuracy of adjacent mA stations is:

exposure linearity

What are the methods of gathering film rejects?

have central place to put rejects, categorize them by type (overexp., underexp., positioning, motion, artifacts, doubleexp, etc.)

How should aprons be stored?

hung up when not in use

The filtering effect of the xray tube's glass envelope and its oil coolant are referred to

inherent filtration

What is light field-radiation field congruence?

measures how well the collimator regulates the field size and if the area illuminated by the positioning light and the area exposed by the xrays are the same

The QC rresponsibility of collimation assessment is assigned to whom?

medical physicist

What device is used to measure the luminance of a monitor?

photometer

What is used to measure the luminance of a CRT screen?

photometer

What are filtration tests?

proves that filtration is/is not sufficient Make several exposures of the dosimeter, reading mR each time. Tape Al sheets one at a time to the tube and take exposures until mR is < ½ original reading

What is AEC?

provides uniform radiographic density regardless of patient size, part, position, and density of the area

The regular measurement and evaluation of radiographic equipment components and their performance is most accurately termed what?

quality control

The primary purpose of filtration is

radiation protection

Congruence of the x-ray beam with the light field is tested using what?

radiopaque objects

What is Illinois Emergency Management Agency?

regular (every two years usually) inspections. Test things that affect patient dose (collimator, exposure, half-value layer, timer, etc)

How often is preventative maintenance done?

regular inspections, cleaning, adjusting units. Most of this is done by service engineers 4X/yr

What is the Joint Commission?

requires ongoing written documentation of QM procedures

What is reciprocity in mA accuracy tests?

same mAs should be given same density with different mA and time combos. Make 3 exposures at [email protected]; [email protected]; [email protected].

How often are radiographic collimator's required to be evaluated?

semiannually

When and who does the monitor calibration?

service engineer, approximately 4x/year

A three phase timer can be tested for accuracy using a synchronous spinning top. The resulting image looks like a

solid arc, with the angle (in degrees) representative of the exposure time

What is reject analysis?

systematic study of all radiographs determined to be unacceptable by QA tech, or by the reading Radiologist

Define quality assurance.

the planned and systematic actions that provide adequate confidence that a diagnostic x-ray facility will produce consistently high quality images with minimum exposure of patients and personnel

What is quality assurance?

the planned and systematic actions that provide adequate confidence that a diagnostic x-ray facility will produce consistently high quality images with minimum exposure of patients and personnel. Deals with people

What is linearity in mA accuracy tests?

the proportional accuracy of 1 mA station compared to another

What is the definition for Half Value Layer?

the thickness of absorber necessary to reduce an x-ray beam to half its original intensity

Programs that deal with the safe and reliable operation of equipment and programs that address all aspects of the delivery of radiology services are called:

total quality management

When must aprons and gonadal shields be checked?

when received and then every 6 mo. after (must be annually at a minimum)

How much the alignment of the IR and radiation field be?

xray beam must be mounted properly in metal housing and aligned to bucky 8 penny test or collimator test tool can be used, just like the previous slide

What is the SSD limit for mobile equipment?

≥ 12"

What is the SSD limit for fluoro equipment?

≥ 15"