Given their pervasiveness in hospitals, one could be forgiven to take picture archiving and communication systems (PACS) for granted. However, in reality, they have been around for less than two decades. The first PACS prototype was set up in 1990 at the University of California, and soon after at Hammersmith Hospital in London. Commercial products began to enter the market 3-4 years later but serious growth in PACS use was seen only in the early 2000s.
PACS: boost to productivity and imaging demand
PACS revolutionized workflow between radiology and other hospital departments, resulting in a gigantic leap in productivity. PACS also catalysed the growth of imaging, especially computed tomography (CT) and magnetic resonance imaging (MRI) scanners, whose huge masses of data it was able to process, store and forward to different users on demand.
Along with older X-Rays and ultrasound (whose data are also managed by PACS), CT and MRI devices have become integral to nearly every single surgical procedure, as well as the medical management of chronic diseases ranging from arthritis to cancer. In acute care settings such as A&E, their availability has directly contributed to a fall in patient waiting times and increased the efficiency of triaging.
2007: 3D video of beating heart
Until recently, 2D PACS was the only realistic choice. In spite of an explosion in core processing power and storage capacity, PACS technologies had been consistently outpaced by developments in CT, which permitted imaging of increasingly thinner slices, outputting exponentially larger volumes of data.
In 2007, Toshiba launched Aquilion One, with a capability of acquiring five 320 slices per second and attaining a highly-symbolic milestone – to image a beating heart in 3D video.
Most PACS systems at this time only allowed viewing in 2D, or required time-consuming reconstruction of the original 3D image. The challenge of speed continued to remain a critical barrier for several years, as did limits to data storage.
Such hurdles could not be easily overcome, in spite of powerful pressures from a new class of users of imaging data, the surgeon. Unlike radiologists, who were trained to use their imagination to work with ‘abstract 2D thinking’, surgeons lacked such a gift; indeed, evidence of their inability to work with 2D images go back to the birth of modern imaging technologies in the early 1990s.
From thin client servers to the Cloud
3D systems have since become more widespread. PACS workstations deployed on large thin-client servers address some (if not all) of the challenges of speed; they also allow one radiologist to manipulate data from CT scanners transferred to the server from a range of locations, and output this in 3D.
The Cloud now promises to take this further, with images moving from servers to virtual networks at data centres. This offers several advantages: distributed access to data (doing away with the need for users to go through separate hospital firewalls), extreme redundancy (no risk of server failure) and last but not least, lower costs (cloud-based services generally offer use-based pricing models).
Algorithms for multimodal rendering
Another development lies in the algorithms powering a new generation of visualization techniques such as HARDI (High Angular Resolution Diffusion Imaging) and DSI (Diffusion Spectrum Imaging). These dramatically increase available horsepower in the PACS and permit multi-modal rendering, especially for MRI and CT image combinations.
However, their impact is potentially even more far-reaching. Indeed, 2007 (the same year Toshiba launched its pathbreaking Aquilion One) also saw publication of a study on an interactive, high-resolution combination of data from CT and MRI as well as from fMRI (functional MRI), PET (positron emission tomography) and DSA (digital subtraction angiography); together, the data was used successfully for a neurosurgical intervention.
Today, healthcare technology stands at a new threshold – the arrival of molecular imaging. However, this is still some years away. In the meanwhile, there are several trends worth noting.
Growth rate for imaging equipment slows
The first is a slowdown in the growth of the imaging equipment market in the West. In the US, the respected Harvey L. Neiman Health Policy Institute recently highlighted “a dramatic and sustained slowing” in both the utilization of imaging and budgetary spends on new equipment.
An obvious explanation for the above is saturation. Almost every hospital or other healthcare facility requiring a CT or MRI scanner already has one.
The Neiman Institute also assesses other reasons for this, among them technological maturity, a growing awareness about the risks of radiation, as well as several factors related to cost and regulatory policy which have cut down unnecessary or ineffective imaging procedures. The success in disseminating imaging results across the hospital (which, as noted earlier, is a direct result of PACS) has directly reduced duplication of tests.
European 3D, BRICS imaging remains strong
The decline in Western market growth, however, may not be even. In Europe, the 3D imaging segment is expected to continue growing, as applications became increasingly affordable. Meanwhile, elsewhere, the BRICS countries and much of the Asia-Pacific are likely to emerge as the fastest growing markets for imaging systems, according to a report ‘3D Medical Imaging: A Global Strategic Business Report’, from US research firm Global Industry Analysts.
PACS sees convergence of new tech, replacement cycles
Data acquisition is one thing, data management quite another. Unlike imaging, the PACS market is not heading for any slowdown in the foreseeable future, even in the US.
A Kalorama Information study forecasts US spending on PACS growing by double-digits each year through 2015, driven largely by new technologies. This technology-driven push, in turn, couples on the demand side into an impending cycle of replacements of old systems and/or upgrades.
Typically, new PACS technologies parallel those in the computing world, especially in data storage. Included here are faster in-built case read time, scan-to-read time and scanner utilization. Other emerging areas are more medical-specific, such as topological data representation (to show the surface and shape of organs) and hyper-realism (the addition of realistic light and shade effects). Applications for such technologies go beyond radiologists and surgeons to GP offices, for example in the shape of optical coherence tomography (OCT) scanners which use deep penetration near-infrared light (rather than sound) to create 3D images, and can be used for conditions ranging from otitis media to diabetic retinopathy.
One new niche is 4D PACS, which can store and manage ‘videos’ constructed by assembling CT scans over a period of time. Another is multi-subject datasets, with imaging of more than one subject to determine patterns and interactively compare multiple patient histories.
Such developments, in turn, pave the way for what would be the Holy Grail of any surgeon, to create realistic images of surgical outcomes.
The iPad/iPhone effect
As the back-end of imaging systems, PACS is also expected to become increasingly friendly to hand-held and mobile use. Leading the way here are Apple’s ubiquitous iPad and iPhone, though Blackberries are also commonplace.
The sharp growth in the use of such devices by medical professionals was pointed out by the 2nd Annual HIMSS Mobile Technology Survey, published in December 2012. Another study, by Manhattan Research, found almost two-thirds of US physicians using mobile devices, doubling the adoption rate since 2011.
Several mobile devices now have powerful graphics cards and meet the basic demands of interactive 3D rendering as well as what has become known as ‘zero-download’ – or instant access to patient information, along with cross-platform support.
Though technology for zero-download clients is still inadequate for manipulation of high resolution images, this is expected to change as vendors home in on a clearly massive business opportunity.
Skype for PACS
One side effect of the increase in use of mobile devices is an enhancement of relationships between radiologists and physicians. The two now increasingly share images and enter into conversations rather than the asynchronous practice of radiologists interpreting images and physician reading their reports.
In December 2012, Paul Nagy, Director of Quality at the Russell H. Morgan Department of Radiology at Johns Hopkins University, told ‘Diagnostic Imaging’ that due to growth in the use of mobile devices, “we can now bring back consultation and bring back our relationship with our referring physicians... Basically, what we’re talking about is like Skype for PACS.”
PACS has also driven the next step in mobility, with access to 3D images by radiologists and a full range of surgeons and other healthcare professionals from their homes, while commuting and between consultations. Teleradiology, as this field is known, has been around for decades but is being galvanized by mobile PACS. Indeed, new mobile (or mHealth) teleradiology offerings are a key driver behind growth of nearly 20% a year in the global teleradiology market, according to researchers TechNavio.