Unit 9 - MI 238

department of environmental protection (DEP)

related to x-ray equipment registrant responsibilities

to require registrants to have a quality assurance program

quality assurance

addresses repeat rate, image recording, processing & viewing, maintenance & modifcations to program

often improves image quality & reduce pt exposure

continuous quality improvement (CQI)

ongoing process that focuses on evaluating & improving performance overtime

proactive problem solving → analysis to improve pt care

tools & technique → uses audits, performance indictators (pt feedback)

open teamwork & communication for continuous learning

standard of quality

high standard of safe & effective imaging practices

specific requirements for a quality mangement system

demonstrates provide products & services that meet customer & regulatory requirements

FDA

who sets the standards of quality?

the Joint Commission & PA Deparment of Health

what state & national association are the Standards of Quality measured by?

communication

quality assurance committee

must occur between entire imaging department & inter-departmentally

quality assurance committee

primary function to maintain lines of communciation among all groups

quality mangament manual

should be made readily avaialble to all personel

at least annually

how often should the quality assurance manual be reviewed?

centeral refernce document

manual outlines of quality policies, procedures & responsibilities for consistent departmental practices

supports training & consistency

aids onborading & ensures uniform quality practices across staff & shifts

ensures compliance & improvement

manual demonstrates structured quality during inspections & support continuous updates for improvements

responsibility & administration

routine quality control monitoring & maintence system incorporating state of the art procedures that should be established & conducted on a regular schedule

quality control techs → day to day adminstration of program

quality control techs

carry out monitoring duties day to day that are beyond the level of training of staff tech

staff tech

physicists

supervising tech

quality control tech

staff service engineers

who are professionals that can do QM?

administrative leadership

over see quality activites, compliance & resources allocation w/in department

support education, open communication & pt safety

verfiies the QC testing effective

involvement in quality control

ASRT: The Practice Standards for Medical Imaging & Radiation Therapy Radiology Practice Standards

QC testing & monitoring, preventive maintenance & corrective maintenance

ASRT: The Practice Standards for Medical Imaging & Radiation Therapy Radiology Practice Standards

participates in ongoing quality asssurance program

test equipment

accurate & well-maintained

ensures reliable quality control results

standardized procedures

consistent, standardized testing procedures reduce variability & allow comparsion of results over time

staff training & competency

ensures techs can perform test correctly & interpret results to maintain quality

quality control test of equipment

calibration & monitoring of equipment & repeat analysis

4 main components of QC program

may require support from outside vendors

acceptance of testing of the equipment

establishment of baseline performance parameters

diagnosis of correctable deviations

documentation of actual corrections made

what are the 4 components of the QC program?

how much the process or equipment neturally changes

how old the euqipment is

how important that part is to producing a good image

what does the frequency of QC test depend on?

preventive maintenance procedure

performed on a regularly scheduled basis w/ the goal of preventing breakdowns due to equipment falling w/out warning signs detectable by monitoring

record keeping

data must be recorded after each perfromance test & kept on file

provides proof that quality control test was perfromed

test review

ensures euqipment & procedures meet established quality standards

must be timely to address issues promptly

to prevent negative impacts of pt care

why should issues be address promptly?

first level of evaluation

results from the monitoring procedures

used to evaluate performance of equipment

second level of evaluation

evaluating the effectiveness of their program

quality assurance program

an organized effort by the staff operating a facility to ensure that diagnostic images produced are high quality

consistently provides adequate imaging info. at the lowest possible cost & w/ least amount of pt exposure

what does it mean when we say “to produce the highest quality of imaging”?

quality assurance

prevents problems → plans & policies

department reviews protocols, trends, education & corrective action

fixes the system

quality control

detects problems → checks & tests

finds issues

techs identifies & documents the problem

exposure indicator accruacy

image integrity

what are the components of image quality control?

expsoure indicator accuracy

provides valuable info about exposure to the IR

evaluated along w/ image quality

image integrity

verification that images are saved in PACS

performed at end of procedure

technologist

who are the first in line of defense in preventing, recognizing & reporting QC issues?

weekly

how often are IR maintence inspections?

monthly

how often are IR maintenance cleaning?

weekly

how often does RH erasure the IR systems?

10 X 10 collimation w/ 2 pennies in the center w/ relatviely high technique

9 X 9 collimation, no pennies w/ relatively low technique

what is the weekly erasure test?

CR reader

how does a CR cassette get erased?

0-80

what is the acceptable EI value in a re-exposed image?

faint remnant of previous anatomy or objects → ghosting

non-uniform area related to prior exposure

repeatable artifacts indicating incomplete erasure

what happens if the DR equipment fails to erase an image itself?

equipment calibration

checks the equipment’s accuracy & ensures consistent image quality

corrects drift

shortens lift of tube

affect pt exposure

affect quality of image

what happens if the equipment is not recalibrated?

DR calibration

pixel sensitivity

machine does it automatically

BIOMED will take action after the service

ensures accurate detector signal response across the detector

CR plate reader calibration

plate wear = change in system senstivity

ensures accruate plate reading & signal conversion

non-uniform shading

banding & striping

dead/stuck pixels

image log

incorrect exposure response

what are some DR calibration issues?

non-uniform shading

light & dark in creatin regions

banding & striping

vertical/horizontal lines across images

dead/stuck pixels

black/white spots

image log

residual outlines from previous image

incorrect exposure response

image appears too noisy or smooth

laser/PMT miscalibration

streaking

ghosting

increase noise

what are some CR reader calibration issues?

laser/PMT miscalibration

uneven brightness across image

streaking

bands aligned w/ plate scan direction

ghosting

residual outlines from previous image

increased noise

grainy appearance unrelated to exposure

uniformity

ALL digital detectors are inherently nonuniform

corrections must be repeated → daily-semi-annually

purpose for evening out the overall signal/brightness across entire image field

why must uniformity corrections must be repeated on a daily-semi-annually basis?

phantom

what is used to test spatial resolution?

lines pairs per millimeter

what is spatial resolution measured in?

spatial resolution test

compares previous test images

change in image quality brings to service engineer’s attention

reject analysis

crticial that repeat exposures are identified

allows solution to be found to minimize repeats

department monitoring

repeat reasons

number of repeats

techs responsible

how are the reject analysis idenifying the repeated exposures?

quarterly

how often is the reject analysis done?

not exceed 4-6%

what is the minimum percentage of repeats rates?

causal & total

what are the types of department monitoring for reject analysis?

department monitoring caual

% of repeats from a specific cause

department monitoring total

all repeats no matter what the cause

pt exposure monitoring

part of QA program

recording of modality specific dose indices, associated equipment settings & pt habitus obtained → air kerma

identification & analysis of dose index values & conditions that consistently deviate from corresponding norms

radiation dose index monitoring system (RDIM)

GE: dosewatch

what are the vendor-supplies software for pt exposure monitoring?

GE: dosewatch

automatically collect & analyze pt radiation & iodine exposure acorss multi-facility imaging environments

radiographic QC testing

requires sepcialized equipment

corrective actions taken only by service personne;

filtration & half-value layer (HVL)

only true measure of actual x-ray beam penteration

minimum HVL must be achieved

annually

how often is the filtration & HVL tested?

protective filtration

used to remove low-energy x-rays from the beam that cannot penetrate the body

2.5 mm of aluminum

what is the graded thickness minimum of the protective filters stated by the state?

there is a need for calibration of the kVp due to insufficient filtration in the beam

if the HVL falls below the minimum requirements indicate, what does that means?

1.5 mm of aluminum

at 70 kVp what is the minimum HVL?

2.3 mm of aluminum

at 80 or 90 kVp, what is the minimum HVL?

greater

the value should be _______ than the minimum required HVL according to the FDA

kVp accuracy test

expose at various levels w/ consistent mAs values

annually

how often is the kVp accruacy tested?

± 5

what is the acceptable range in diagnostic for the accuracy of kVp?

exposure linearity

alignment of a particular mA station relative to other stations in it output of radiation

annually

how often is the exposure linearity tested?

should double w/in ± 10 %

during the exposure linearity test, each time the mA is doubled, what should happen to the mR/mAs?

exposure reproducibility

ability to repeat the same technique setting & obtain the same results in exposure

exposure reproducibility test

make 10 exposures w/ identical settings for exposure time, mA, & Kvp

sum up all exposures & divide by 10

compare each reading to get the average

annually

how often does diagnostic exposure reproducibility should be tested?

w/in ± 5%

what is the acceptable range for the diagnostic exposure reproducibility?

time accuracy

major repairs performed

part replacement to generator or console

annually

how often should the timer accuracy be tested?

± 5%

unless exposure times less than 10 ms

what is the acceptable range for diagnostic timer accuracy test?

beam alignment

perpendicularity

verticality of the central ray is indicated by a metal screw/BB embedded in the center if the cylinder top & bottom

x-ray beam must be w/in 1 degree (5mm) of vertical alignment (w/in inner circle)

what are is the acceptable range for diagnostic beam alignment test?