Picture Archiving & Communications System (PACS)
Picture archiving and communication systems (PACS) are computers or networks dedicated to the storage, retrieval, distribution and presentation of images. The medical images are stored in an independent format. The most common format for image storage is DICOM (Digital Imaging and Communications in Medicine). It can store volume data from exams and reconstruct 3D images.
PatientSoft PACS can handle images sent from various medical imaging instruments, including Ultrasonography (US), Magnetic resonance imaging (MRI), Positron emission tomography (PET), Computed tomography (CT), Endoscopy (ENDO), Mammography (MAMMO), Digital radiography (DR), Computed radiography (CR) amongst others.
PatientSoft PACS has two main advantages:
- Hard copy replacement: It replaces hard copy based means of managing medical images. With the decreasing price of digital storage, it provides a growing cost and space advantage over hard copy archives in addition to the instant access to prior images.
- Remote access: It expands on the possibilities of conventional systems by providing capabilities of off-site viewing and reporting and it enables practitioners in different physical locations to access the same information simultaneously for tele-radiology.
Architecture: Typically a PatientSoft PACS network consists of a central server that stores a database containing the images connected to one or more clients via a LAN or WAN, however more and more, the Internet is the means of communication. This is usually via a VPN (Virtual Private Network) or through an SSL (Secure Sockets Layer) connection. PatientSoft PACS accommodates all of these approaches.
For a system to be truly web based each individual image should have its own URL. PatientSoft PACS allocates a separate URL to each image it collects. This maximizes its performance as a web based solution.
Client workstations can use local peripherals for scanning image films into the system, printing image films from the system and interactive display of digital images. These are primarily used by general practitioners, medical specialists and allied health professionals. PACS workstations also offer the means for manipulating the images (crop, rotate, zoom, window and level). These are primarily used by consulting radiologists.
Modern radiology equipment and modalities feed patient images directly to the PACS in digital form. For backwards compatibility PatientSoft PACS supports the use of a film digitizer.
Image backup is a critical but sometimes overlooked part of the PACS architecture. There are several methods of backing up the images, but they all typically involve automatically sending copies of the images to a separate computer for storage, preferably off-site. Computer images are fragile and can be lost very quickly. It is important that facilities have a backup copy of the images. While each facility is different, the goal in image backup is to make it automatic and as easy to administer as possible. Ideally, copies of images should be sent off-site as they are created. Depending on bandwidth and image volume, this may not be practical. Other options include removable media (hard drives, DVDs or other media that can hold many patients' images) and/or separate computers. These copies need to be protected. PatientSoft PACS supports all of these approaches.
In the event that it is necessary to reconstruct the data base from the backup images PatientSoft PACS is able to be turned into a "super modality" that simply sends all of its images back to the server. This will allow it to continue receiving current images while also rebuilding its historical images at the same time.
PatientSoft PACS facilitates backup that is inexpensive, automatic, requires no downtime and isflexible enough to be used for partial or full restores, as well as migrating images to a new PACS.
Integration: A full PACS should provide a single point of access for images and their associated data (i.e. it should support multiple modalities). It can interface with existing the Hospital Information System (HIS) and Radiology Information System (RIS). Interfacing between multiple systems provides a more consistent and reliable dataset:
- Less risk of entering an incorrect patient ID for a study Ð modalities that support DICOM worklists can retrieve identifying patient information (patient name, patient number, accession number) for upcoming cases and present that to the technologist, preventing data entry errors during acquisition. Once the acquisition is complete, the PACS can compare the embedded image data with a list of scheduled studies from RIS, and can flag a warning if the image data does not match a scheduled study.
- Data saved in the PACS can be tagged with unique patient identifiers (such as a Medicare number). Providing a robust method of merging datasets from multiple sources, even where the different centers use different ID systems internally.
An interface can also improve workflow patterns:
- When a study has been reported by a radiologist the PatientSoft PACS marks it as read. This avoids needless double-reading. The report can be attached to the images and be viewable via a single interface.
- Improved use of online storage and nearline storage in the image archive. The PatientSoft Integrated RIS & PACS can obtain lists of appointments and admissions in advance, allowing images to be pre-fetched from nearline storage (for example, tape libraries or optical jukeboxes onto online disk storage (RAID array).