RAD370 - CH12/13 Quality in PACS

People Centered quality

(QA) Quality Assurance

Product centered quality

(QC) Quality Control

Most health care institutions are accredited by

The Joint Commission (TJC)

Accreditation is voluntary but necessary to

• Obtain Medicaid Certification

• Hold certain licenses

• Obtain reimbursements from insurance companies

• receive malpractice insurance

QC data from various activities

are kept by designated individuals

• Acceptance testing

• Routine maintenance

  • can catch problems before they are apparent

• Error Maintenance

Major categories of QC tests

testing before newly installed or equipment with major repairs accepted by department

Acceptance testing

• testing by vendor’s specifications

• DICOM

• AAPM

• SMPTE

• ACR

monitor quality for electronic image displays

Digital Imaging & Communication in Medicine

DICOM

American Association of Physicists in Medicine

AAPM

Society of Motion Picture & Television Engineers

SMPTE

American College of Radiology

ACR

• requires compliance with standards to ensure quality

ACR creates/suggests tests

be carried out with a SMPTE test pattern

• carried out monthly

also widely accepted for use in QC activities pertaining to digital monitors

Test pattern developed by AAPM Task Group 18

AAPM has a much more rigorous schedule

testing be performed on acceptance and annually by a trained physicist 

Daily and monthly or quarterly tests can be performed by

• trained QC technologist

• physicist

Monitor Quality

weakest link in digital imaging chain

• daily/monthly/quarterly QC - trained technologist

• Annual + acceptance - medical physicist

• warm up monitor

• check for dust

• use test pattern (SMPTE or TG 18 QC)

• evaluate image of test pattern

• luminance meter or photometer

Daily

• Geometric pattern (test pattern)

• reflection (other sources of light)

• luminance response (TG 18-LN test pattern) and photometer resolution

Monthly

SMPTE (picture)

AAPM TG18 - QC (picture)

rate of light emitted from an LCD screen

Luminance

total rate of light emitted

Unit of candula (Cd)

device measuring the luminescence of areas on the monitor

Photometer

• Contrast

• Resolution

• Noise

general areas that define digital image quality

first line of defense in preventing, recognizing, and reporting QC

Technologist

Strongly recommended that a personal repeat rate log be kept by each technologist

• vendors have software that automatically keeps repeats

Reject Analysis

• allows technologist to see possible trends in exposure error

Service personnel have a duty to patient to ensure equipment is maintained properly

(PM) preventive maintenance

• takes place semi-annually

• Reestablish baseline values

• check exposure indicator accuracy with calibrated ion chamber

• determine exposure trends

• analyze repeat rates

• review QC records

• Analyze service history

Physicist Responsibilities

AAPM established QC parameters for PSP in

AAPM Report #93

QC standards for PACS can be found in

ACR, AAPM, and equipment vendor