What is PACS in Healthcare?
A PACS in healthcare is a Picture Archiving and Communications System – a digital system used to store, retrieve, and transmit medical images captured from devices such as X-ray machines, MRI scanners, CT scanners, and ultrasound machines. The acronym PACS is still commonly used in healthcare despite being retired by the FDA in 2021 in favor of MIMPS (Medical Image Management and Processing Systems).
Medical imaging has come a long way since Wilhelm Roentgen discovered X-rays in 1895. Originally maintained on physical glass plates and (from 1918) photographic film, medical images were first captured digitally and communicated via Intranets in the 1970s. The subsequent development of the DICOM standard in the 1980s enabled the storage and transmission of medical images via otherwise incompatible devices and networks.
Later versions of the DICOM standard in the 1990s improved the interoperability of PACS in healthcare. Support for HL7 standards facilitated the integration of scheduling and billing software, while improvements to HTTP transport capabilities via Port 80 enabled remote access to systems. As technologies evolve, PACS in healthcare are being developed with AI capabilities that can improve image analyses, automate image management, and accelerate diagnoses.
The 4 Primary Components of a PACS In Healthcare
Due to the different ways in which healthcare organizations operate, there is no one-size-fits-all model PACS infrastructure. Most sources identify either four or five primary components of a PACS in healthcare – the difference often being that some sources list backup servers as separate components. Although backup servers are necessary for HIPAA compliance, the backup component is included in the operations of the PACS server in the following list.
Image Acquisition Devices
Image acquisition devices have traditionally been limited to X-ray machines, MRI scanners, CT scanners, and ultrasound machines. However, an increasing number of wearable technologies support HL7 standards, which means that images transmitted by wearables can be received by EMRs and accessed remotely via the PACS.
The PACS Server
The PACS server connects with onsite image acquisition devices directly and with wearable devices via EMRs. The images received from the devices are most often sent by the PACS server to an Archive server so they can be accessed by onsite and offsite terminals, and to a backup server to ensure the integrity and availability of the medical images.
The PACS server may also have a function known as a Modality Work List (MWL) which extracts data from the Hospital Information System to manage which tasks should be performed on which patients on which devices. Once an image is received, the corresponding task is flagged as complete, and the facility’s practice management software is notified for billing purposes.
Workstations, Viewing Stations, and Remote Terminals
In a PACS infrastructure, workstations and viewing stations are onsite terminals connected to the PACS server by a Local Area Network (LAN) on which images can be accessed, viewed, manipulated, and interpreted for diagnoses. Modern high-resolution terminals can also include image processing software, a local database, and communication tools.
With regards to remote terminals (i.e., terminals that connect via the Internet or Wi-Fi), some PACS in healthcare limit the capabilities of remote terminals to read-only for security purposes. Even then, remote terminals should have robust access controls to ensure only authorized personnel can access the PACS remotely and audit logs to monitor user activity.
A Secure Network
Networks used for the distribution and exchange of patient images must be secured to the standards required by HIPAA while still facilitating the flow of information necessary to comply with healthcare quality measures. In many cases, it is possible to achieve both objectives by applying the principles of a healthcare compliance program to a PACS network.
PACS or MIMPS in Healthcare?
In 2021, the FDA amended the classification of Picture Archiving and Communications Systems to Medical Image Management and Processing Systems (MIMPS) in order to “reflect changes to the Federal Food, Drug, and Cosmetic Act made by the Cures Act”. The amendment excludes certain software functions from the definition of a Picture Archiving and Communications System – specifically the software used for facilitating storage, archiving, and communication.
The amendment has been described as “little more than housekeeping” to conform to the medical software provisions of the Cures Act and should have no impact on healthcare providers. However, the amendment will have a minor benefit for vendors of PACS/MIMPS hardware components, who will no longer need 501(k) clearance for the software capabilities of the hardware components before the hardware components can be marketed.
As a result, it is acceptable to refer to a PACS in healthcare as a PACS or as a MIMPS. There are effectively the same thing except for how the FDA classifies them. Healthcare organizations and vendors of PACS hardware components that require further information about the FDA’s 2021 amendment are advised to seek advise from a healthcare compliance professional.
