Hi,
Mike is correct in his explanation but if I may go further with extra detail in that:
In the UK, radiology equipment and other medical devices are treated separately by different professions so documents or guidance reflect accordingly and now goes so far as to be treated separately by imaging, radiotherapy or nuclear medicine professionals. In summary - treat separately to other devices for the many reasons Mike lists.
Geoff raises comparisons with older x-ray technology. I think this needs to be discussed separately as a chat rather than the discussion request. I teach BEng and MEng Biomedical students and those that do not listen to my lectures go on to refer to the internet where there is vast amounts of "old" information instead of using my slides. The bottom line for up and coming radiology engineers is - don't look back and stick to what you are taught about current equipment - then take history lessons from oldies like me and Mike.
Hope the above doesn't sound flippant but I'm trying to distill issues.
WRT - "in my experience, the highest risk of unnecessary patients doses arose from "repeat" exposures due (in the main) to what we might call "operator error" (bad patient positioning, incorrect selection of factors, etc.)."
This is all covered by the IR(ME)R Regs and is about patient exposure and very little is now due to x-ray equipment. What clouded the regulatory aspects of equipment in the past was that HSE got involve with all equipment failures but the latest change in law in 2017 saw this move to the IRMER2017. This is where you need to understand about the latest handover form as well. You also have to be able to distinguish device failures (MHRA) and exposure failures that are QA related.
"Aren't we really talking about the welcome change from film cassettes (and wet-processing) to Computerised Radiography? And won't most (almost all) exposures these days be terminated by AEC techniques such as (Siemens) Iontomat? Has anyone we know had a go at retro-fitting CR to old x-ray systems? Was it a cost-effective solution? And (perhaps most importantly) did patient doses decrease - or even increase?"
This overlap period has now waned and is a massive discussion in itself. Exposures are still terminated by the HT generator but software and detector technology has put it into the black box category and you can't fix it any more like most stuff.
"Meanwhile, I am interested in the matter of x-ray exposure dose. Myself, I doubt that dose for equivalent examinations have decreased that much over the last ten, twenty (or perhaps even thirty) years. I know that early CT blasted out hefty doses of the "magic rays", but I reckon they improved quite quickly (maybe as far back as thirty years ago). But I am more interested in traditional (conventional) radiography (the sort of thing that Dr.Röntgen would instantly recognise). Does anyone have any documentation (charts etc.) about exposure dose-rates over the years?"
UKHSA (was PHE) have responsibility for national dose reference levels. These are updated and require a lot of work to collate what to post on this site by Medical Physics Experts at UKSHA.
https://www.gov.uk/government/publi...l-diagnostic-reference-levels-ndrls/ndrlHope this helps?
Ian
