Storage issues may require editing at the start

May 6, 2005

A principal question in cardiac digital imaging is not so much how to store the enormous amounts of data generated by cardiology studies, but which portion of the data to store.

A principal question in cardiac digital imaging is not so much how to store the enormous amounts of data generated by cardiology studies, but which portion of the data to store.

"Cardiac cath studies so large that sites often struggle with 'How much can I store of what I capture?'," said Deniese Chaney, a senior manager at Capgemini Health.

Cardiac cath or flouro studies might produce an hour and a half worth of data amounting to 700 to 800 MB. When preparing to store the data, cardiologists often must pare the study down to about the top 20 minutes of video or cath data.

"You either have to have massive storage, or you have to decide to save just what you consider to be relevant, discarding some of the original data," Chaney said.

An abridged study can actually be helpful later.

"One reason to save only the relevant data is that when cardiologists go back later to compare studies, they don't have to look at an hour and a half worth of data to find what they need," she said.

A companion issue is how to transmit streaming video through the enterprise.

"Assuming you want to actually see this movie in the same time frame as it was taken, you're talking about streaming video of large digital images, which requires high-end broadband connectivity in the 100 Mb/s range," said John Quinn, chief technology officer for Capgemini's provider practice.

It's not that it can't be done. But cardiology sites will probably have an isolated network in the hospital to support streaming video, or everyone else on the network will be at the mercy of these heavy traffic loads, he said.

"Streaming large amounts of video data versus typical IT packets presents a different type of performance demand on a network," Quinn said.

Many hospitals resolve this potential bottleneck by isolating cardiology traffic on a subnet, he said.

That doesn't mean that subnet users can't access the rest of the IT network. The idea is to isolate the predominate users of heavy streaming video into an area where they're not going to be interfered with by the rest of the network and where their work can proceed without interfering with everyone else, Quinn said.