Case study - Mobile imaging service with unique study workflow needs

The largest mobile imaging services provided conducted a two year search for a PACS to meet their unique workflow needs. Traditional PACS systems were designed for large hospitals and did not adapt to the company's distinct and comples workflow. In addition, the price tag of a conventional PACS was price prohibitive.

Challenge

The study workflow was the opposite of a traditional radiology imaging center workflow. Normally, a patient is registered, the study is performed, and the study is interpreted. In the case of the mobile imaging service, patient information was entered manually in the field, and as such was sometimes incorrect. Some patients were scheduled in advance, but many times the studies were performed in the field before actually being registered in the practice management system.

Studies were performed during the day at more than 35 vans and trailers. Many of the vans had a need for a 'lite-PACS' in the van to receive studies from the modalities, allow corrections or additions to header information in the studies, then batch download the studies to the PACS.

At the end of the day, the studies were downloaded to the PACS for distribution when the vans returned from the field. The PACS had to process a full day's worth of studies in about 1 hour so they could be sent out to the reading radiologists.

There was no set of rules that could be set up to determine which reading radiologist received which studies, so it was necessary to provide a quick and easy way to electronically duplicate the manual method for sorting and distributing studies that had previously been use.

Finally, studies were sent to reading radiologists for interpretation. The reading workstations needed to operate like a miniPACS, which would populate the radiologist worklist with studies to be read, plus store studies for a certain time to be available for later review. The workstations needed to operate independently of the central PACS.

Solution

The advantage of a modular PACS was demonstrated in every aspect of the solution Connect Imaging implemented.

The first requirement of a very fast module to receive studies from the vans and process them into the archive was satisfied with FileRoom and FileClerk. These software services do the basic job of processing studies, and as such do their job very fast. These services can process studies to the limit of the incoming network connection.

The second requirement of a distribution engine to allow studies to be easily sent to the reading radiologists was satisfied with Distributor. Studies were forwarded from FileRoom to Distributor, where they were kept in a local cache for several days to be available for sending out to the radiologists. Since Distributor ran on a separate computer, the distribution of studies did not slow down the processing of incoming studies, nor did it compete with FileRoom for network bandwidth. Modifications were made to the program to satisfy the need to manually forward goups of studies to individual radiologists, plus see which studies had not been forwarded to anyone. Detailed tracking documentation was built into the program to allow users to see exactly how many images of which studies had been sent, along with the date/time of when they were sent.

The third requirement for a 'lite PACS' in the van to receive studies from the modality and allow the user to modify the demographic information was satisfied with Tech Workstation. Tech Workstation is a simple program that can receive studies via DICOM transfer from the modalities, allow changes to be made in the patient demographic data in the DICOM header, then send the studies to another DICOM receiver, this time the PACS archive. Since the original installation, features have been added to Tech Workstation to alert the user if he tries to delete a study from Tech Workstation that has not been sent to some other location.

Finally, the requirement for a diagnostic workstation that could run independently of the main PACS and also store studies for an extended period was satisfied by combining the FileRoom module and the ViewBox module. The FileRoom is very fast, but is also very small and takes up limited machine resources. Studies sent to the workstation are stored in a mini archive on the workstation, then pushed to the ViewBox workstation. Since both FileRoom and ViewBox use different databases on the same Microsoft SQL server database system, the overhead of database maintenance is also minimized. The FileRom service has a separate purge module that prunes the studies periodically, so the workstation hard drive does not fill up.

Benefits The mobile imaging service was able to increase their efficiency by being able to replicate their manual workflow, that had been developed over time to be as efficient as possible, with an electronic workflow to do the same thing. Costs involved with producing, sorting, and distributing films were eliminated, and turnaround time from study to interpretation was reduced. Recently, the company successfully added digital mammography to their modalities, with the same efficient workflow for storage and distribution of studies. Return to case studies...