The archive is expected to free health care providers from the hassle and cost of copying scans to CDs when a doctor wants to review patient medical images taken by another provider.

Piloted by HealthInfoNet, the state’s health information exchange, the archive is being tested by three health care organizations. The pilot kicks off formally on Thursday at MaineGeneral Medical Center in Augusta and Waterville, followed by Eastern Maine Medical Center in Bangor and Cary Medical Center in Caribou later this month.

An estimated 1.8 million X-rays, CT scans, MRIs and other medical images are generated in Maine each year, according to HealthInfoNet. The three pilot hospitals and Central Maine Medical Center in Lewiston, which was involved in designing the pilot and plans to participate, generate 1.4 million of those images.

Medical images are stored and accessed through a number of different repositories and networks across the state, making it difficult to share them among health care organizations. Providers sometimes can access other providers’ medical imaging networks but may not know to look for a scan in the first place or have trouble finding it.

Easier access will mean doctors don’t have to wait for medical image records and can more easily track changes in patients’ health over time, such as the growth of a tumor.

“The fact that [a patient’s] provider has full access to all the prior images and reports collectively, can go quickly in real time and look through the images, see the trends, see the cancer growth, see whatever it is they’re looking at and then make a clinical decision, is extremely powerful,” said Todd Rogow, HealthInfoNet’s director of information technology.

Difficulty viewing medical imaging records can lead doctors to rely on only the most recent medical image scan, rather than the patient’s full history, he said.

If a patient had a scan at Eastern Maine Medical Center, for example, but later went to nearby St. Joseph Hospital for treatment, his imaging records would have to be burned onto a CD and toted the two miles to his doctor at St. Joseph, Rogow said.

Hospitals also use different viewers to display medical records, which aren’t always compatible.

If all goes well with the pilot through the summer, the service will be rolled out statewide by early 2013.

“It opens up the entire statewide inventory of images for our providers,” said David Silsbee, chief information officer at Cary Medical Center. “It’ll be most valuable for our radiologists, since the radiologist is seeing a new [medical image] on the patient here, and they can access all prior [medical images] that patient has had done throughout the state. They can make a much more informed decision about whether they’re seeing a new condition or a pre-existing condition or if a condition has changed.”

Many health care organizations have developed private medical image exchange capabilities but Maine is leading in its effort, said John Halamka, chief information officer of Beth Israel Deaconess Medical Center and Harvard Medical School in Boston and chairman of the New England Healthcare Exchange Network.

“To my knowledge, no state has implemented a public image exchange,” he said.

HealthInfoNet is partnering with Dell to host the cloud-based archive. Dell will foot the bill for the hardware and storage during the pilot phase and providers will pay for images by subscription after the statewide rollout.

The archive is expected to save $6 million over seven years by sparing providers the cost of storing and transporting medical image records, plus the expense of paying staff to hunt for them.

The service also is expected to cut down on repeat tests would save money and limit patients’ exposure to potentially cancer-causing radiation given off by some imaging scans.

A primary care doctor, for example, could log on to the health information exchange to see if a patient needing a chest CT already was scanned at the local hospital, Silsbee said.

“In a case like that we can save a patient a couple thousand dollars and some radiation exposure,” he said.