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| Pranav Shah |
Remember the old days when modality workstation was the only means of advanced visualisation and volumetric analysis. The so called ‘workstation’ was perceived as the most valuable resource and was the only means by which multi-slice CT, MRI and PET/CT procedures could be efficiently interpreted and reviewed. Generally speaking, nothing is wrong with it as far as it goes.
Most CT scanners come bundled with a 3D workstation offered as part of the package, and these workstations often have good software for providing 3D interpretation support. The problem is that there is usually only one supplied per CT or MR, and purchasing an additional one is very expensive.
The CT technologist usually needs access to the workstation for various management tasks, and so there is competition for this valuable resource that can only be used by one person at a time. As a result, physicians often have to interpret from 2D viewer looking at static images created by technologists, precluding the possibility of pursuing a diagnostic decision tree that requires multiple consecutive questions to be addressed in 3D.
The key problem that has arisen with the introduction of MDCT is how to provide cost effective volumetric interpretation support to interpreting and referring physicians, and this is where the ‘bundled’ workstation falls down. Failing to plan for an Enterprise Advanced 3D solution is planning to fail. So let us understand how modern technology and software innovation would make this 3D advanced visualisation available to all.
Technological challenges and innovation in medical imaging
Making advanced visualisation available to a broad enterprise poses some technological challenges. This is not like browsing the web where the processing power required is small and the data volume transferred is manageable. Modern MDCT datasets can run to gigabytes and the processing power needed to render them in real time 3D pushes the very limits of modern computing technology. As a result there is tremendous value in being able to avoid moving the large CT datasets around to multiple computers across the enterprise, and in being able to avoid reliance on the processing power of whatever computer may be available out there to do the 3D rendering itself.
This is where the client-server architecture comes in and this is where it brings such an advantage. All the data can be centralised into one server, which can easily be located close to the modalities or PACS, such that the transfer is fast. This server, if equipped with a huge amount of processing power, can then provide rendering services to many computers across the enterprise which can run a simple application to control the server and receive a real time stream of images for display. This effectively turns every computer in the enterprise into a 3D workstation and if the power and feature set of the server is adequate, this becomes a really elegant, viable and cost-effective solution for delivering advanced image processing to everyone who needs it.
This ‘thin client’ approach, when implemented properly, is also excellent for PACS integration because, since it makes no significant demands on the client-side hardware, it can easily run alongside the PACS software without impairing its performance and still be available for instant access in 3D.
Volume rendering technique and client-server architecture
The key differences between the 3D technologies in the market relate to the technology used for 3D rendering and the general architecture of the system. When the CPU of a computer is used for 3D rendering, a general purpose processor designed for Microsoft applications performs a specialised medical imaging task, often with poor efficiency and performance, even when compromises are made in image quality. The same is true for GPU rendering, as ‘video cards’ in most computers are mainly designed for computer games. These cards deal primarily with ‘polygon’ graphics and typically do a poor job on anatomical data, with compromises in terms of performance and image quality.
As a result, such systems usually have to calculate additional information about every dataset that is received, just to prepare it for 3D rendering, which takes time, memory and CPU power, and the results must then be stored on the hard drive, consuming additional space. The alternative is to use a dedicated hardware processor specifically designed to perform medical visualisation where the slice data can simply be downloaded to the board’s memory without any delay or additional processing, with real time 3D following. Such a system can have the power and scalability to manage a true client-server deployment powerful enough for an imaging enterprise.
Third-party 3D vendors generally have some architecture to address the enterprise solution, which has an emphasis on client-server and dedicated board based rendering technology platform. Usually they are designed for such enterprise wide advanced 3D visualisation and when packaged with advanced clinical applications makes physicians less dependent on the modality workstation. A truly capable enterprise solution based on a client-server solution enables multiple users to use any networked standard PC as a 3D workstation and use various clinical applications for diagnostic interpretation and review.
Inbuilt automation
Nowadays, software innovation alongwith client-server architecture, allows automatic preprocessing of datasets. The server automatically pre processes datasets performing assigned tasks such as bone removal, rib cage removal, CT table removal, automatic vessel extraction and drawing centerlines, etc. When these tasks are automated and performed off-line, results are delivered to a technologist or physician without them having to initiate the process and then wait for it to complete, and hence, valuable time is saved.
PACS with 3D capabilities enhances workflow
Integration of advanced visualisation tools with PACS is not essential, but it does help smooth the workflow and it can save a few additional seconds of locating the patient for a second time when you want to work in 3D. If you have a PACS, check if the 3D vendor can integrate and if so, how easy is that to realise? Is there a cost on the PACS vendor side? If you have not yet purchased your PACS, think ahead and ensure advanced 3D clinical capabilities is part of the PACS package!
Seeking access to 3D tools outside your hospital? Look to the cloud
There is definitely a challenge and it may also sound expensive for centres with low volume to provide advanced visualisation to all. Hospitals have to invest into hardware and software solutions to deploy such server-client solution. Moreover, it is confined to your hospital and if you need to reach outside your hospital to share or collaborate it can get complicated. With true client-server technology, healthcare providers are now offering cloud based advanced visualisation. Wherein as a customer you don’t need to invest in purchasing entire solution but enroll for a subscription. It is like software as a service (SaaS). Physicians have to upload their cases through secured gateway onto the cloud servers provided by vendor and by any web browser a physician can access entire suite of clinical applications. A strong Internet bandwidth of 3-5Mbps is essential for using cloud accounts and with recent IT and telecommunications regulations, and there are no foreseen major challenges in getting such Internet connections. There are companies which provide smart uploader facility by which the time taken to upload your studies is minimised. Using secured browser-based access, mobile devices like iPhone and iPads can also be used to access cloud servers.
Contact Details:
Pranav Shah
Regional Sales Manager, Terarecon
Mob: 9819192754
Email: [email protected]
