Developing an automated QC program for ACR accreditation compliance Quality Control

31 Pages·2013·4.92 MB·English

3/10/2013
Developing an automated QC
program for ACR accreditation
compliance
*Kiaran P. McGee, Ph.D., Scott Stiving MS, Paul Bao
Ph.D. Dianna Lanners, Teresa Peterson, Renee
Jonsgaard
*Associate Professor of Radiologic Physics
Mayo Clinic & Foundation
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Quality Control: Mayo Perspective
•Image quality a primary focus of Department
of Radiology mission.
•Quality control (QC) viewed as an essential
tool for maintaining optimal image quality of
imaging systems.
•In-house methods developed to monitor and
maintain image quality.
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Mayo Clinic MR QC: Historical Review
•Technologists scanned manufacturer’s QC
phantom.
•Script run on scanner to extract and process
images
•Distortion and Signal-to-Noise (SNR) ratios
calculated and reported on file
•Program prompted user to rescan if failed or
proceed if passed.
•Two failures required call to QC technologists
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Manufacturer QC Phantom
Phantom and External Fiducials
Phantom
Fiducials
Phantom and RF TR
Head Coil
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QC Data Files
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QC Reports
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Manual QC: The Good, Bad & Ugly
 Stringent quality control
measures are preemptive:
able to identify problems
before equipment fails
Reduces downtime and
unscheduled maintenance
- Manual record keeping is
time consuming and labor
intensive.
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Quality Control & Accreditation
Quality Control
•Quality control and
accreditation are
interlinked:
•Accrediting agencies
require establishment
of QC program for
maintenance of
accreditation
•QC programs provide
important, quantitative
feedback on system
performance.
Accreditation
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What is Accreditation & Why Do It
•Definition of Accreditation: To recognize or
vouch for as conforming with a standard.1
•Why accredit imaging systems:
•Ensures minimum image quality for
diagnostic imaging
•QC initiatives provide method for ongoing
image quality assessment
•Allows comparison of image quality across
different institutions
•However, a prime motivator is financial.
1Merriam-Webster dictionary
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Medicare Improvements for Patients
and Providers Act (MIPPA) of 2008
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Advanced Diagnostic Imaging Services
MIPPA Act - 122 STAT. 2532, SEC 135.
Advanced Diagnostic Imaging Services:
I. Diagnostic magnetic resonance imaging,
computed tomography, and nuclear
medicine (including positron emission
tomography).
II. ….. excluding X-ray, ultrasound, and
fluoroscopy.
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UnitedHealthcare’s (UHc) new policy to reimburse
only for medical imaging performed in accredited
facilities. The new policy goes into effect on March
1, 2008.
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CMS Approved Accreditation Agencies
•The ABR is not the only agency approved by the
Centers for Medicare and Medicaid Services
(CMS) – the US federal agency which administers
Medicare, Medicaid and State Children’s Health
Insurance Programs.
•CMS recognizes three accreditation agencies:
•American College of Radiology (ACR)

•Intersocietal Accreditation Commission (IAC)

•The Joint Commission (TJC)
Ambulatory Care Accreditation Program
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ACR MRI Accreditation Process
For sites to become ACR accredited they must:
1. Submit initial accreditation package
including phantom and clinical images.
2. Satisfy minimum image quality criteria for
those data.
3. Establish & maintain an ongoing weekly
quality control (QC) program in compliance
with ACR QC recommendations.
©2012 MFMER | slide-14
ACR MRI Weekly QC Standards
• Parameters derived from T1-weighted sagittal and axial images of ‘ACR
phantom’ :
Center frequency
Transmit Gain/Attenuation
Geometric accuracy
High-contrast spatial resolution
Slice thickness
Slice position
Image intensity uniformity
Percent-signal ghosting
Low-contrast object detectability
Signal-to-noise
• All phantom images are reviewed and free of artifacts
• MR Table and operator console are fully functional
• The following have been visually inspected:
Patient transport and magnet
Filming & Viewing
RF integrity
Facility safety
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ACR Recommended Testing Frequencies
Technologist’s Weekly QC Tests Physicist / MR
Scientist Annual
QC Tests
•Center frequency •Low-contrast resolution •Magnetic field
homogeneity
•Table positioning •Artifact analysis •Slice position accuracy
•Setup and scanning •Film quality control •Slice thickness accuracy
•Geometric accuracy •Visual checklist •Radiofrequency coil
checks
•High contrast resolution •Soft copy displays
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Why Automate The QC Process?
•Mayo performs daily QC checks
•Compliance with ACR QC requirements was
taking ~ 30 minutes per MR scanner.
•Limited personnel resources to perform daily
QC.
•No incremental staffing to meet ACR QC
requirements.
©2012 MFMER | slide-17
Daily ACR QC Workload
Daily ACR QC – Single Scanner
Daily ACR QC – 8 Scanners
Other (450 min)
AOCthRe rD (a2i4ly0 QmCin ()30 min)
ACR Daily QC (240 min)
In 2004, 8 MR scanners represented ~
30% of our total fleet (24 MR Scanners)
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The Bottom Line: Unsustainable
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So you want to develop your own
automated QC program!
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Our Experience
•Approximately 12 months of development by
team of two programmers for:
•Web and database development
•Algorithm development
•Testing
•Implementation
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Project Phases and Development
Define Project Scope & Deliverables
Web Page Design and Usability Testing
Algorithm Development & Testing
Clinical Rollout
0 1 2 3 4 5 6 7 8 9 10 11 12
Development Month
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Specifications
•System must process ACR images from
multiple vendors (Siemens & GE)
•Process images of the ACR phantom data
acquired at multiple field strengths and RF
coil types.
•System must process data with minimum
delay time
•User friendly and accurate
•Display, report and analyze data

©2012 MFMER | slide-23
Web Application Overview
Institutional MR Scanners
Intranet Accessible User PC
Sagittal localizer &
aimxiaagl eTs1 -owf eAigChRte QdC
phantom DICOM Daily QC review and
pushed to analysis additional QC
workstation checks performed
by technologists &
physicists through
web portal to QC
Images processed to extract 7 databases
ACR QC metrics
Institutional SQL Institutional Web Server
Daily ACR QC metrics Database
sent to SQL database
Communication between
web server and database
DICOM receiver and analysis server arellvoiwews ianntder taoclteirvaen dcaet as etting
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ACR QC: Initial Findings
•Experience is a great teacher:
•Largest cause of ACR QC failures were
not related to image quality but due to
poor phantom positioning.
•To address this problem, a immobilization
jig was built to ensure the phantom is
always positioned at the same place
within the head coil.
©2012 MFMER | slide-25
Phantom Positioning
Spirit Level will aid in positioning
with split head coils and Siemens
Head Matrix.
Poor positioning will decrease
SNR value and may result in a
repeat exam. Image is angled 5°.
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Head Coil Types
GE Split Head Coil Siemens Head Matrix
GE 8 Channel Head Siemens T/R Head
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Mayo – ACR Daily QC: 5 Basic Steps
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