A Brief Introduction to Veterinary PACS

One of the digital radiography concepts that perplexes veterinarians when shopping for a digital system is a mysterious thing called PACS.  PACS is an acronym for Picture Archiving and Communication System. The problem is that is about all that vendors can agree upon. Shopping for PACS is complicated because many vendors talk about the need for PACS, other vendors don’t mention PACS, and some vendors sell PACS with names such as mini-PACS, or web based PACS. Have no fear. You will soon be able to understand what all of these words mean and then some.

The Animal Insides definition of PACS:

PACS (picture archiving and communication system) is defined as all of the computer software, hardware, and the computer network that is used to store your digital images for future access, backup your images for safekeeping, distribute your images around your hospital, and interface with your practice management software, ultrasound machine, and other imaging modalities in an integrated digital environment.

This is a pretty broad definition, which is why there is so much confusion regarding PACS. For example, a singe doctor practice who never sends images for review and only needs to view their images on a single computer and who does not own an ultrasound machine could (theoretically) store and view all of their images on a single computer. In this situation, the PACS requirements of the hospital really only comprises a software viewer with limited functionality and hardware running on that single computer.  Conversely, a 5 doctor, progressive veterinary hospital, will have PACS requirements that are much more robust. In this hospital PACS needs may include

1. Viewing images at 12 places, simultaneously around the hospital
2. Integration with their practice management software
3. The ability to accept ultrasound images
4. Need to send images to three different teleradiology groups
5. Require a high volume redundant backup solution
6. Require a viewer to be able to view CT studies from an outside referral hospital. This will include 3D reconstructions
7. Provide for the ability of different doctors to use different viewers
8. Allow the surgeon to use digital templating software
9. Veterinarians want to access images from home
10. The front desk staff will burn a DVD with the images from all of the patients that are radiographed in the hospital.

In this situation the PACS requirements are very different than for the single doctor practice as the PACS will need to be much more robust to accomplish all of these tasks.

The first take home message about PACS is that PACS requirements will vary depending on the needs of the veterinary hospital. This is why there are so many PACS options and shipping for PACS can be confusion.

The basic PACS workflow

In an effort to help describe how the different pieces and parts of PACS fit together, many veterinarians find it useful to follow an image through the hospital. This introduction to the PACS workflow will help acquaint you with the different components of PACS. The terms in BOLD are jargon words that you will inevitably hear when shopping for digital radiography systems.

1. Step 1: An image is generated in the radiology room on a digital acquisition device such as a CR or DR machine or an ultrasound machine.
2. Step 2: Using a DICOM transfer, the images are sent to a local PACS server, which stores the image in a local archive.
   1. This archive should be able to store images of many different types such as ultrasound, dental radiography, and CT or MRI. This archive, thereforecan be used as the central repository of all images in the hospital.

1. Step 3: Redundancy (backup) is always warranted so a second image is also stored in an on site or off site archive.
2. Step 4: When a user wants to retrieve the image, a DICOM viewer is used to send message a message to the local PACS server, which retrieves it from the archive. This process is also known as querying the database and retrieving the images
3. Step 5: Images are then viewed on a workstation running the DICOM viewer.
   1. The DICOM viewer has all of the controls veterinarians can use to view the images such as window and level, zoom, and adjusting the contrast of the images.
   2. It is important to note that DICOM viewers can run on the same computers you use to run your practice management software. The number of viewers you have in the hospital will depend on the number of seat licenses you purchased with your system.
   3. In most cases, the vendor will sell or provide you with a DICOM viewer of their choosing. It should be noted, that with many PACS systems, many different DICOM viewers can be used. This is possible because of a service called DICOM query/retrieve (DICOM Q/R). If using different DICOM viewers will be important to you, be sure your PACS supports DICOM query/retrieve.