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Archive through February 14, 201114-02-11  05:04 pmJamie Clifton20
 
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 Link to this message James Watson  posted on Monday, February 14, 2011 - 05:43 pm Edit Post Delete Post Print Post
I represent a PACS provider and so have a commercial interest here.

I think the decision to host a service in a cloud has to be made on a case by case basis. However, outsourcing your service to a cloud is generally about convenience to the customer. The provider takes care of the day to day running of the system and any faults or issues that occur, and the local IT department or radiology dept pays for not having to worry about that element of the system.

If you want super fast access to images in a cloud then that can be arranged, the biggest issue would most probably be the links between the data centre and the viewing endpoint. Faster throughput = greater cost.

In real terms though, Storage is cheap these days and its easily possible to have 6TB of protected storage for less than 5K - I expect that would be enough to cover a lot of the oldest images, whilst keeping them online and readily accessible for instant viewing. That sort of solution in a hospitals own computer room shouldn't cause anyone a headache as its pretty much static data and should only be a matter of changing a failed disk every now and then.

If your PACS uses standard windows file systems to store images then it should be possible to split the storage area into fast storage for recent images and cheaper storage for older images. If you are lucky the storage has grown over time and you will find that your oldest images are on a disk partition that could be replaced by cheaper options...
 Link to this message Richard Mann  posted on Tuesday, February 15, 2011 - 08:45 am Edit Post Delete Post Print Post
I don't think friendly debate undermines anyone.

It's not clear to me why N3 is a bottleneck either - but it's pretty relevant to the discussion if we are considering offsite storage. Anyone know if it also comes up for re-negotiation soon?

Jamie - there are a few possibilities for the A&E scenario. If you have prefetching set up from your PAS, then you'd expect an A&E attendance (patients have to be booked in to the A&E dept on arrival to start the clock ticking) to trigger retrieval. Or maybe the new activity on RIS if they go for new imaging.

If you haven't gone down the prefetching route, then I guess you would be hoping that either the clinician who requests imaging or the radiographer who does it will notice there is previous and retrieve it. Depends on whether staff routinely check for previous imaging I suppose?
 Link to this message Neelam Dugar  posted on Tuesday, February 15, 2011 - 11:15 am Edit Post Delete Post Print Post
Excellent friendly debate here. :-)

Yes, LSP CDS stores contract also end in July 2013 (I think that is the date being stated). Hence, there are many options being considered. I hope Trusts will have a choice. Choice will allow for innovation.

"clinician who requests imaging or the radiographer who does it will notice there is previous and retrieve it"--My concern is when we introduce manual processes to prefetch--- we will not have the images available when we need them. The problem is that when an image is not avaialable clinicians will just read the report (which is available) rather than wait 15minutes to retrieve the image. My arguement is that if we are going to be dependent to reviewing reports--why store images--just delete them & save money. If we store images they must be available in a timely manner at the point of patient care.

I think we need to go back to basics
1. We need to store images (John Parkers posting)
adults - keep for 7 years
Paeds - until they are 21
medico legal - forever
This is a finite volume of storage we require. PACS systems must be able to delete (or compress) images after this. PACS must be able to follow business logic, and get this information from PAS about medicolegal flags.
2. Options for storage will include
a. Everything online (on spinning discs) by your local PACS supplier onsite
b. Everything online provided by your "Cloud PACS supplier"---as described by Henry. As described by Henry this is basically a "Cloud PACS" with display & storage data centre hosted.
c. Part storage by local PACS on spinning discs--18months (by PACS vendor who provides display) ---with local VNA (non-PACS vendor DICOM archive)/DVD/tapes for older images which rely on prefetch to ensure timely display of images at clinical frontend.
d. Part storage by local PACS on spinning discs--18months (by PACS vendor who provides display) ---with data centre hosted VNA (non-PACS vendor DICOM archive) for older images--- which rely on prefetch to ensure timely display of images at clinical frontend (similar to LSP CDS architecture we have today).

There will be pros & cons, variation in prices of each of the models. A good debate is what is required to allow Trusts to make the right decision. Perhaps Autumn 2011 Meeting debate?
 Link to this message Martin Peacock  posted on Tuesday, February 15, 2011 - 01:32 pm Edit Post Delete Post Print Post
Neelam.. There is another possibility to have data part local and part cloud - you've covered the prefetch options but there is in IHE Access to Radiology Information profile an option for the Image Display Actor to support multiple sources (section 7.3 in Technical Framework Vol I). The display can then simultaneously Q/R from local PACS AND the cloud.

That presupposes that the PACS doesn't add value by virtue of being the middle man but I don't think thats a big ask. What may be is to get workstation vendors to support multiple sources.

Offtopic: A little strange that in RCR Imaging Informatics Group forum, RCR, Informatics; PACS ; IHE and DICOM are highlighted as spelling errors! :-)
 Link to this message Neelam Dugar  posted on Tuesday, February 15, 2011 - 02:19 pm Edit Post Delete Post Print Post
Big fan of IHE.

However, it does not help this issue at all. In my view, ARI profile is superceded by XDS which will allow an XDS/XDS-I consumer to view images & documents stored in various XDS/XDS-I repositories provided it is registered on your XDS registry (Correct me if I am wrong here)

The issue is to have access to stored images in a timely manner ---3-5secs but not more than 15secs. If you cannot provide timely access to clinicians---delete the images & save taxpayers money is my view.
 Link to this message Richard Mann  posted on Tuesday, February 15, 2011 - 02:49 pm Edit Post Delete Post Print Post
Agree 15 minute wait would be tedious. The 10 minute CDS service level I referred to probably had a fair bit of slack built in - which would fit with our experience.

We've referred to the legal requirement to keep images (and there seem to be some practical issues with culling older images) so just deleting them isn't an option.

If trusts are seriously considering making a change isn't Autumn 2011 a bit late?
 Link to this message Neelam Dugar  posted on Tuesday, February 15, 2011 - 06:10 pm Edit Post Delete Post Print Post
Trusts can fulfill their 'legal' requirements to retain images, once reported by radiologists, by dumping them onto cheap & cheerful DVDs and dont make them available to anyone but lawyers. This will save millions of pounds of taxpayers money. Sorry, I am getting more & more cynical about why we in the NHS are storing patients images--- is it to support patient care is it just to fulfil our legal obligations as an organizations.

If the purpose if storing images is to support patient care then these images need to be available in a timely manner. Most NHS doctors have 10-15 minutes to consult with a patient. They review the notes prior to patient attending. They talk/examine patients requests tests, dictate a letter. I do not think they will wait more than 15secs for images. If images take more than 15secs most will simply read the report if available.

We as a community need to decide why we are storing images and then find the cheapest method of doing this.
 Link to this message Neelam Dugar  posted on Tuesday, February 22, 2011 - 11:28 am Edit Post Delete Post Print Post
Most Trusts will have taken a pragmatic approach just like John Parker for film culling --prior to PACS.
adults - keep for 7 years
Paeds - until they are 21
medico legal - forever

However,going through the various docs on DH, CFH & RCR websites---There is lack of clarity about WHY we are retaining patients records:
1. Is it to support clinical/patient care?
2. Or is it a simply for legal reasons?

I think we need clarity on this issue. As this has huge implications of the cost of PACS we procure in the future. I will request Dr. Nicola Strickland to discuss this at the College and get a view from College.

A.If we are storing patients images for clinical patient care then they need to be available within 3-5secs (but not more than 15secs).

B. However, if we are storing images simply for legal reasons then we need to store them as cheaply as possible---e.g DVDs in a locked cabinet. As they are very unlikely to be retrieved.
 
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