Title: Potential problems displaying PET/CT Scans accurately on IMPAX

Category: Patient Safety Briefing

Sent date: 19/12/07 (resent with title)

Reference: PACS 07 31

Background:

Sheffield Teaching Hospitals NHS Foundation Trust has reported that when reviewing PET/CT Scans imported via CD from the Alliance Service the slices were inappropriately displayed (Safety Incident Report reference SIR 241). This is because each axial slice is, by default, scaled to its individual maximum pixel value within the slice rather than the global maximum of the entire data set. Additionally, when the images are loaded they may initially be scaled incorrectly; it is reported that the correct scaling is only applied once the user has altered the window levels.
The potential clinical risk is that when imported PET/CT scans are reviewed by a clinician the incorrect scaling may disguise or distort the clinical picture – with the potential for an inappropriate treatment decisions to be made on the basis of a review process rather than a primary diagnostic process.


Briefing Information:

This bulletin is being issued to alert users to the possibility that when reviewing PET/CT Scans imported into PACS the images may be scaled incorrectly. Please be advised that particular caution should be exercised when attempting to interpret the image, especially when what is observed does not appear to accord with the written report.

Accenture and Agfa are investigating the reported issue and will be providing Connecting for Health with regular updates –once the investigation has been completed and a course of action determined and agreed an updated bulletin will be published.

Additionally, users are reminded that IMPAX as currently deployed does not contain the additional tools needed to “fuse PET/CT images”. Primary reporting and diagnosis from PET/CT Studies should not be undertaken from within IMPAX, but from an appropriate workstation designed and approved for the purpose.
Users need to ensure that diagnosis of all images is undertaken from a workstation designed for diagnostic reporting, not a web viewer or client PC that is designed for review purposes only.

Necessary Actions:

·  Review whether your trust is importing PET/CT Studies into PACS and, if so, please inform the Accenture Service Desk so they can keep you informed of findings as the root cause analysis progresses Additionally, if you do import such studies please can you see whether you also experience incorrect scaling of the images on initial view – if so please notify Accenture and the National Service Desk using the reference “PET Import Scaling Issue” to ensure that accurate tracking of the problem occurs?

·  Disseminate this information to your colleagues

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