The picture archiving and communication system is a continuously evolving technology. It started as a system designed purely for radiologists and is now largely regarded as a means for the healthcare enterprise to capture, store, interpret and share all types of images within an organization and externally. This technology has been changed through regulations (meaningful use, Affordable Care Act, longitudinal care), as well as through user demands to access images from anywhere, on any device.
When considering a picture archiving and communication system (PACS) integration, an organization needs to address the environment in which it will be used (inpatient, ambulatory, emergency, specialties) and the other electronic systems with which it will integrate (electronic medical record (EMR), radiology information systems (RIS), dictation, advanced visualization, storage and archival). The organization also must be aware of the PACS' ability to access historical data and grow in size, as well as service new areas (cardiology, pathology, burn centers, etc.). In addition, IT experts must understand its cost to implement and maintain, as well as the ability to replace it without expensive data migration costs.
An organization needs to make an initial decision whether it will purchase a PACS as a capital expense or whether they wish to operationalize the cost. Where to host the PACS is another issue. It can be hosted in-house, at a remote hosting facility or in the cloud (as Software as a Service). These decisions will significantly change the range of vendors that can provide the desired solution(s).
Today there is a PACS configuration for nearly any setting: imaging centers, doctor offices with X-ray equipment, clinics, hospitals with multiple imaging centers, etc. The larger the organization, the more complex the collection and distribution of the data becomes. On the acquisition side, the imaging modalities might generate large files (computed tomography (CT) angiography, echocardiogram ultrasound, positron emission tomography, computed tomography, pathology, etc.) that will make demands on the network, especially if the images need to be moved over a WAN to off-site locations.
Depending on the level of specialization, incoming studies will need to be distributed to specialized radiologists' reading lists. If multiple RIS and EMR systems are ordering and scheduling studies, additional software may be needed to create a federated worklist. The list combines and prioritizes the incoming studies, requiring reports regardless of its source. There may be additional state requirements such as the California Senate Bill 1237, which requires detailed reporting of radiation doses delivered to patients during acquisition of CT exams. Such mandates usually result in additional software that must integrate with the other systems and the overall workflow.
Cardiology systems rely more heavily on structured reporting, and thus need to be compatible with DICOM SR (digital imaging and communications in media structured reporting) to allow measurements to be pulled into the report. With the improvements in voice recognition (VR), many groups are forgoing the traditional report dictation -- transcribing and reviewing -- and moving to VR. One advantage of VR is the ability to use templates and deliver finalized reports to the referring physician with minimal delay.
Many systems come with built-in tools to handle 3D volumetric depictions, measurements, alternate cross-sectional views, removal of tissue types (bone, muscle, etc.) and merging of images from multiple modalities. There is considerable variability among vendors, and the companies that have specialized in post-processing of images can provide astounding results with easy-to-use interfaces and a wide array of tools. These specializations can cost hundreds of thousands of dollars.
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The effect of PACS on health IT
How radiology moved PACS images to PHRs
Surgical specialties need accurate measurements for selecting and placing joint replacements, as well as tools for simulating surgeries. An emerging field involves the printing of bone matrices, such as the skull, using 3D reconstructions from prior CT scans or mirroring a healthy part of the skull structure. Radiation oncology also uses 3D images to minimize collateral radiation to healthy tissues. Each of these specialties can integrate with the established PACS vendors to varying degrees. A specialty department can always import the DICOM image for standalone processing. Working with the stakeholders will establish the need for seamless integration between PACS and the ancillary specialty systems.
Once the signed report is delivered, the image delivery system needs to address how clinicians -- especially those outside the facilities sphere of software -- will be able to view and report on the images. The traditional model of dedicated image viewing stations is fading. New computers can easily provide a clear and detailed image to the user via Web servers. Users now wish to review images anywhere, anytime, on any type of device (smartphones, tablets, laptops).
Satisfying this need raises security and compliance issues. HIPAA requires all data be encrypted, whether it is static (stored) or being transferred. The use of up-to-date devices running on HTML5 provides zero-footprint viewing. This means no data is stored on your device. As soon as the image is removed from your viewing, the information is gone as well.
In the past, Adobe Flash's and Oracle's Java cached information was retained and could be re-accessed by a knowledgeable user, thus exposing organizations to liability if the device was lost or stolen. Another change in the image-viewing environment is the universal viewer. This viewer uses the same rendering software regardless of whether the user is a radiologist, specialist or referring physician. It also aims to make the viewing experience the same regardless of whether the user is on an iPad or workstation.
Image storage comes with its own set of requirements. The cost of hard-disk storage has dropped so rapidly that most facilities can easily store three to five years of data on-site and have it immediately available to their PACS. Storing this data in a redundant fashion to safeguard against disasters and protecting the data so it's available for future studies is a challenge. All too frequently, PACS and data centers are in the basement where they could suffer damage from a water main break or a natural disaster. Today there are multiple services that provide excellent fixed-cost, off-site storage of images on disks and tapes. The level of redundancy these services offer is hard to beat by a small- or medium-sized enterprise.
The image database is one of the most overlooked costs of any PACS. When considering PACS integration, this is usually included in the purchase price.
There has been a steep cost of migrating historical data from one PACS generation to the next when changing vendors because many vendors added proprietary information to the standard DICOM structure. This information would have to be painstakingly extracted and sent to the new system in a manner it could understand, or it was lost. A typical image data migration usually takes months, if not years, depending on how much data needs to be moved and the digital media on which it was stored.
I have seen facilities spend considerable sums keeping a decrepit archiving system functional while historical data was moved. Vendor neutral archiving (VNA) assures data is always stored in a fashion that all PACS adhering to DICOM Part 10 can access and interpret it. Using VNA, the owner can replace PACS far more easily and remove the cost of data migrations.
The DICOM standard is showing its age. Setting up and managing imaging departments requires constant maintenance and troubleshooting. A full-time PACS administrator is nearly mandatory, depending on the size of your image archive. Frequently, additional help is needed for on-site troubleshooting of the modalities or the maintenance of the RIS system.
All requirements have a cost and no single system can satisfy all requirements. The market has both established and new PACS that offer competitive and comprehensive solutions.
Martin Kappeyne is the principal at Green Leaves LLC and has specialized in assisting larger hospitals and groups implement enterprise applications with a particular emphasis on emergency medicine, radiology, and cardiology, and general workflow adaptation using LEAN methodologies. Let us know what you think about the story; email firstname.lastname@example.org or contact @SearchHealthIT on Twitter.