ABSTRACT
The recommended methods to test the performance of computed radiography (CR) systems have been established
by The American Association of Physicists in Medicine, Report No. 93, “Acceptance Testing and Quality Control
of Photostimulable Storage Phosphor Imaging Systems”.1 The quality assurance tests are categorized by how
frequently they need to be performed. Quality assurance of CR systems is the responsibility of the facility that
performs the exam and is governed by the state in which the facility is located. For Example, the New York State
Department of Health has established a guide which lists the tests that a CR facility must perform for quality
assurance.2 This study aims at educating the reader about the new quality assurance requirements defined by
the state. It further demonstrates an easy to use software tool, henceforth referred to as the Digital Physicist,
developed to aid a radiologic facility in conforming with state guidelines and monitoring quality assurance of
CR/DR imaging systems. The Digital Physicist provides a vendor independent procedure for quality assurance
of CR/DR systems. Further it, generates a PDF report with a brief description of these tests and the obtained
results.

Keywords: Quality Assurance, Quality Control, AAPM, New York State Guide
1. INTRODUCTION
Quality assurance of CR systems is the responsibility of the facility that performs the exam and is governed
by the state in which the facility is located. For Example, the New York State Department of Health has
established a guide which lists the tests that a CR facility must perform for quality assurance.2 Current state
guides are developed based on the acceptance evaluation plan, detailed in AAPM Report No. 93 section 8.3. The
acceptance evaluation plan consists of dark noise, uniformity, laser beam function, spatial resolution, low contrast
resolution, spatial accuracy, artifact examination, contrast/noise, laser jitter, exposure indicator accuracy and
few others. Each state guide instructs the CR facility to conform with the standards set by the state and to
maintain records for atleast three years. The exact tests performed may vary from manufacturer to manufacturer
but must include those quality control checks specified by the manufacturer and be modeled after the program
in the state guidelines.
The Digital Physicist is a Java based framework developed as a paradigm of the acceptance evaluation plan
detailed in the AAPM report No. 93. It uses ImageJ, an open source image manipulation software developed by
the NIH, as a reference library for some mathematical manipulation. The Digital Physicist provides an intuitive
and easy to use graphical user interface (GUI) to perform quality assurance tests, namely - Dark Noise, Linearity,
Uniformity, Laser Jitter, Spatial Resolution, Erasure Thoroughness and Noise/Low Contrast Resolution. It offers
wizard-like work flow to guide the user with instructions for image acquisition and test execution for each test.
The Digital Physicist is modularized and each test is represented as a separate module. The architecture of the
software allows for the addition of more test modules. The Digital Physicist also provides storage and retrieval
functionality for test results. Comparison modules to compare the saved results are provided for a few tests.
The Digital Physicist also provides a reporting module which enables the user to choose from the saved results of
these tests and write PDF reports indicating pass/fail criteria for each test. The report generated is a paradigm
of the QC records that the CR facility maintains to conform with the state guidelines.