IHE: Basic Image Review Profile

Open for Public Comments !

What is the Basic Image Review profile?

The Basic Image Review (BIR) Profile was developed to address physicians frustration with the viewers provided on DICOM CDs. The BIR profile defines a universal set of basic functionality to be provided by vendor's CD viewers, with common user interface elements, so that when a user inserts a CD, the same functions and a similar user interface will be available regardless of vendor. This set of functions has been selected with the feedback of the American Medical Association and other members of the imaging community.

Why is this important to Nuclear Medicine?

Nuclear medicine has long been neglected when PACS image displays are designed, resulting in markedly sub-optimal display of nuclear medicine images. The SNM has worked with the profile authors at the IHE to include essential nuclear medicine features in the BIR profile. Note, however, that the BIR features define a simple "basic" viewer for radiology images, and thus we are quite limited as to how many features we can include. Therefore, it is important that we find exactly the right mix, limiting our requests to only essential NM features.

What Nuclear Medicine specific features are available in the BIR profile?

• Ability to display all NM DICOM image types
• Ability to display PET images
• Ability to view multiple images at the same time. "At least 2 viewports, and at least 2x2 tiles within a viewport shall be supported."
• Side-by-side display of registered PET-CT images, with synchronized scrolling
  • Automatically linked if the vendor codes the images so as to permit this (same DICOM Frame of Reference)
  • Manual linking available otherwise (with ability to scroll images and re-link)
  • Linked cursors or crosshairs, to allow pointing out of the same structures on both images.
• Cine of NM images
• For image windowing, automatic clamping of lower level to zero for NM and PET images
  • When the window settings are changed by dragging the mouse cursor, only the upper level changes.
    (ie, no accidental background subtraction)
  • This feature may be toggled off whenever desired.
  • Currently defined as " vertical movement upward shall lower the upper limit of the window (increase the perceived brightness)"
  • Applies to both NM and PET images, as well as grayscale screen snapshots (DICOM SC objects) if they are marked NM
  • Does not apply to color screen snapshots, which typically cannot be windowed.
  • Windowing of a cine applies to all images in the cine.
  • Similarly, windowing changes apply to all images in a "series", which is typically defined as a set of images acquired as a single acquisition.
• Display of numerical pixel values under the cursor (counts or (if available) SUV units).
• Zoom and pan.

What Nuclear Medicine specific features are excluded from the BIR profile?

• The following features are not permitted in the basic viewer (but the vendor is permitted to provide an “Advanced Mode” which includes these or any other features or user interface embellishments they choose).
  • No color image fusion of PET-CT images (instead, use side-by-side display above)
  • No MPR (generation of sagittal and coronal images from transaxial data)
  • No image processing (region of interest, time activity curves, image filtering, etc is not allowed)
• The following features are permitted in basic viewers but not required
• Ability to apply arbitrary color scales to grayscale images.
• Ability to control the contrast or brightness of a color image.
• Cine of multiple different images at the same time
• All of the above features are "very useful" in nuclear medicine, but did not rise to the level of "essential in every basic viewer" in the opinion of the drafting committee—the intended audience for the basic viewer is both radiologists and non-radiologists, and there is a downside to both vendors and users if the viewer specifications are too complex..

Where can I download the draft version of the BIR profile?

A current draft version of the BIR profile is available for download and public comment on the IHE web site.

How is the document laid out?

Start reading at the Open Issues and Closed Issues; you are strongly encouraged to provide feedback on Open Issues as you read the rest of the document.  The Closed Issues may provide answers to some of the questions you have that have already been answered.  The BIR profile expands the PDI (Portable Documents for Imaging) profile, which clarifies for vendors how to properly make a DICOM CD. You will therefore see some text pertaining to both the BIR profile and the PDI profile in the draft. You may want to then skip ahead to Section 15.x (line 301) which introduces the option to request a BIR compliant viewer be included on PDI CDs and describes details related to such inclusion, as well as hardware and performance requirements.  Section 4.16.4.2.2.5 (line 606) then begins the definition of the basic image viewer itself. 

How can I submit comments?

You can submit comments between March 19, 2009 and May 1, 2009 by following the instructions in the document at line 20—you will need to create a free IHE login account. Alternately, you may find it easier to email me, and I will post a summary of all the comments received. To do this, email Jerold Wallis ( wallisj ). Note you will need to re-type the email address. Please include the words "BIR comment" in the title of the email, and be sure to include in the body your name and institution or company affiliation. When you comment, reference line numbers in the document.  If you would like something changed, if possible please suggest what it should be changed to.

Are vendors required to adopt the BIR profile?

No, but they will be strongly encouraged to do so by the AMA, IHE, and other sponsoring organizations. The IHE (Integrating the Healthcare Enterprise) has a long history of working closely with industry to help guide the solution of problems in medical imaging, and offers ongoing opportunity to vendors for testing and feedback. More information regarding the IHE can be found at http://www.ihe.net/ .

Jerold W. Wallis, MD
Washington University in St. Louis, School of Medicine.