IMIIT99 2729 August 99 Kuala Lumpur

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IMIIT9927-29 August 99Kuala Lumpur

• A Tutorial on
• Standards and Infrastructure in Teleradiology

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Standards and Infrastructure in Teleradiology

• by
• Ng Kwan-Hoong, PhD
• UMMC
• Ong Hang-See, PhD
• UNITEN
• B J J Abdullah, FRCR
• UMMC

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Objectives

• Appropriate utilization of teleradiology can
  improve access to quality radiological
  interpretation and thus significantly improve
  patient care.
• ? To introduce the American College of Radiology
  (ACR) standards that should serve as a model for
  Malaysian health care providers. Relevant issues
  and possible solutions will also be discussed.
• ? To introduce the basic of hospital data
  communication infrastructure. Data communication
  devices, protocols and standard will be
  presented. A sample list of solution providers
  will be given with some suggestions on the
  selection.

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Basis of the Malaysian Teleradiology Standards
being drafted by theMalaysian Radiological
Society
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Standards in Teleradiology

• CONTENT
• 1. What is Teleradiology?
• 2. What are the Functions of Teleradiology?
• 3. When is Teleradiology not appropriate?
• 4. Goals of Teleradiology
• 5. Qualifications of Personnel
• 6. Equipment Specifications

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Infrastructure in Teleradiology

• CONTENT
• 1. Introduction
• 2. Overview of Data Communication
• 3. Local Area Network
• 4. Wide Area Network
• 5. Emerging Technology
• 6. Solution Providers

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• The resource material for this tutorial are
• 1. ACR Standard for Teleradiology
• Revised 1998 (Res. 35)
• 2. Andrew S. Tanenbaum, "Computer Network",
  3rd ed.
• Prentice- Hall, Upper Saddle River, NJ,
  USA.
• ISBN 0-13- 394248-1
• 3. Networking 101
• http//richardbruce.com/networking/
• 4. The impact of teleradiology in clinical
  practice
• - a Malaysian perspective
• B J J Abdullah, K H Ng, R Pathmanathan
• Medical Journal of Malaysia, 54(2),
  169-174, 1999

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What is Teleradiology?

• Teleradiology is the electronic transmission
  of radiological images from one location to
  another for the purposes of interpretation and/or
  consultation.

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What are the functions of Teleradiology?

• May allow more timely interpretation of
  radiological images and give greater access to
  secondary consultations and to improved
  continuing education.
• Users in different locations may simultaneously
  view images.
• May improve access to radiological
  interpretations and thus significantly improve
  patient care.

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When is Teleradiology not appropriate?

• If the available system does not provide images
  of sufficient quality to perform the indicated
  task.
• When a system is used to produce the official
  interpretation, there should not be a clinically
  significant loss of spatial or contrast
  resolution from image acquisition through
  transmission to final image display.
• For transmission of images for display
• use only, the image quality should be
  sufficient to satisfy the needs of the clinical
  circumstance.

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Goals of Teleradiology

• 1. Providing consultative and interpretative
  radiological services in areas of need
• 2. Making radiologic consultations available in
  medical facilities without on-site radiologic
  support
• 3. Providing timely availability of radiological
  images and radiological image interpretation in
  emergent and non-emergent clinical care areas

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Goals of Teleradiology/2

• 4. Facilitating radiological interpretations in
  on-call situations
• 5. Providing subspecialty radiological support as
  needed
• 6. Enhancing educational opportunities for
  practicing radiologists

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Goals of Teleradiology/3

• 7. Promoting efficiency and quality
• improvement
• 8. Sending interpreted images to referring
• providers
• 9. Supporting telemedicine and
• 10. Providing direct supervision of off-site
• imaging studies.

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QUALIFICATIONS OF PERSONNEL

• The radiological examination at the transmitting
  site must be performed by qualified personnel.
  In all cases this means a licensed and/or
  registered radiographer. He/she must be under the
  supervision of a qualified/
• licensed radiologist or a physician.
• It is desirable to have medical physicist and/or
  image management specialist on site or as
  consultants.

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EQUIPMENT SPECIFICATIONS

• Vary depending on the individual facility's needs
  but, in all cases, should provide image quality
  and availability appropriate to the clinical
  need.

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EQUIPMENT SPECIFICATIONS

• Compliance with the ACR/NEMA Digital Imaging and
  Communication in Medicine Standard (DICOM) is
  strongly recommended for all new equipment
  acquisitions and consideration of periodic
  upgrades incorporating the expanding features of
  that standard should be part of the ongoing
  quality-control program.

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EQUIPMENT SPECIFICATIONS

• Equipment guidelines cover two basic categories
  of teleradiology when used for rendering the
  official interpretation
• ? small matrix size (e.g., CT, MR, US, NM,
  digital fluorography, and digital angiography)
  and
• ? large matrix size (e.g., CR and digitized
  radiographic films).

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EQUIPMENT SPECIFICATIONS

• Small matrix A data set should provide
  full-resolution data (typically 512 x 512
  resolution at minimum 8-bit depth) for
• processing, manipulation, and subsequent
  display.
• Large matrix A data set allowing a minimum of
  2.5 lp/mm spatial resolution at minimum 10-bit
  depth should be
• acquired.

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EQUIPMENT SPECIFICATIONS

• A. Acquisition or Digitization
• B. Compression
• C. Transmission
• D. Display Capabilities
• E. Archiving and Retrieval
• F. Security
• G. Reliability and Redundancy

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A. Acquisition or Digitization

• 1. Direct image capture
• The image data set produced by the digital
  modality both in terms of image matrix size and
  pixel bit depth should be transferred to the
  teleradiology system. It is recommended that the
  DICOM standard be used.
• This is the most desirable mode of digital image
  acquisition for primary diagnosis.

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A. Acquisition or Digitization

• 2. Secondary image capture
• a. Small matrix images. Each image should be
  digitized to a matrix size as large or larger
  than that of the original image by the imaging
  modality. The images should be digitized to a bit
  depth of 8 bits per pixel or greater. Film
  digitization or video frame grab systems
  conforming to these specifications are
  acceptable.
• b. Large matrix images. These images should be
  digitized to a matrix size corresponding to 2.5
  lp/mm or greater, measured in the original
  detector plane. These images should be digitized
  to a bit depth of 10 bits per pixel or greater.
  Film digitizers will generally be required to
  produce these digital images.

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A. Acquisition or Digitization

• 3. General requirements
• At the time of acquisition (small or large
  matrix), the system must include
• Annotation capabilities including patient
  name, identification number, date and time of
  examination, name of facility or institution of
  acquisition, type of examination, patient or
  anatomic part orientation (e.g., right, left,
  superior, inferior, etc.), amount and
• method of data compression. The capability to
  record a brief patient history is desirable.

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B. Compression

• Data compression may be performed to facilitate
  transmission and storage. Several methods,
  including both reversible and irreversible
  techniques may be used with no reduction in
  clinically diagnostic image quality. The types
  and ratios of compression used for different
  imaging studies transmitted and stored by the
  system should be selected and periodically
  reviewed by the responsible physician to ensure
  appropriate clinical image quality.

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C. Transmission

• The type and specifications of the transmission
  devices used will be dictated by the environment
  of the studies to be transmitted. In all cases,
  for official interpretation, the digital data
  received at the receiving end of any transmission
• must have no loss of clinically significant
  information. The transmission system shall have
  adequate error-checking capability.

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D. Display Capabilities

• General Display workstations used for official
• interpretation and employed for small matrix
  and large matrix systems should provide the
  following characteristics
• 1. Luminance of the gray-scale monitors should be
  at least 50 foot-lamberts (538 lux)
• 2. Care should be taken to control the lighting
  in the reading room to eliminate reflections in
  the monitor and to lower the ambient lighting
  level as much as is feasible.

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D. Display Capabilities

• 3. Provide capability for selection of image
  sequence
• 4. Capable of accurately associating the patient
  and study demographic characterizations with the
  study images
• 5. Capable of window and level adjustment, if
  those data are available
• 6. Capable of pan functions and zoom
  (magnification) function
• 7. Capable of meeting guidelines for display of
  all acquired data

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D. Display Capabilities

• 8. Capable of rotating or flipping the images,
  provided correct labeling of patient orientation
  is preserved
• 9. Capable of calculating and displaying accurate
  linear measurements and pixel value
  determinations in appropriate values for the
  modality (e.g., Hounsfield units for CT images),
  if those data are available
• 10. Capable of displaying prior image compression
  ratio, processing, or cropping
• 11. Elements of display that should be available
  include
• a. Matrix size
• b. Bit depth and
• c. Total number of images acquired in the
  study.

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E. Archiving and Retrieval

• If electronic archiving is to be employed, the
  guidelines listed below should be followed
• 1. Teleradiology systems should provide storage
  capacity capable of complying with all facility,
  state, and federal regulations regarding medical
  record retention. Images stored at either site
  should meet the
• jurisdictional requirements of the
  transmitting site.

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E. Archiving and Retrieval

• Images interpreted off-site need not be stored
  at the receiving facility, provided they are
  stored at the transmitting site. However, if the
  images are retained at the receiving site, the
  retention period of that jurisdiction must be met
  as well. The policy on record
• retention should be in writing.

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E. Archiving and Retrieval

• 2. Each exam data file must have an accurate
• corresponding patient and examination database
  record, which includes patient name,
  identification number, exam date, type of
  examination, facility at which examination was
  performed. It is desirable that space be
  available for a brief clinical history.
• 3. Prior examinations should be retrievable from
  archives in a time frame appropriate to the
  clinical needs of the facility and medical staff.

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E. Archiving and Retrieval

• 4. Each facility should have policies and
  procedures for archiving and storage of digital
  image data equivalent to the policies that
  currently exist for the protection of hard-copy
  storage media to preserve imaging records.

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F. Security

• Teleradiology systems should provide network
  and software security protocols to protect the
  confidentiality of patients identification and
  imaging data. There should be measures to
  safeguard the data and to ensure data integrity
  against intentional or unintentional corruption
  of the data.

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G. Reliability and Redundancy

• Quality patient care depends on availability
  of the teleradiology system. Written policies and
  procedures should be in place to ensure
  continuity of care at a level consistent
• with those for hard-copy imaging studies and
  medical records within a facility or institution.
  This should include internal redundancy systems,
  backup tele-communication links, and a disaster
  plan.

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The impact of teleradiology in clinical practice
- a Malaysian perspective B J J Abdullah,
K H Ng, R Pathmanathan Medical Journal of
Malaysia, 54(2), 169-174, 1999
Standards Infrastructure in Teleradiology