Research PACS consolidates 450 million diagnoses and reports with 300 million images

The first large-scale research PACS has surfaced at Partners Healthcare in Boston. The CIRAS (clinical image repository access system) was described as a "research goldmine" at the Society for Computer Applications in Radiology meeting.

"CIRAS creates opportunities for research that were not considered conceivable only five years ago," said Dr. David S. Hirschorn, a radiologist at Massachusetts General Hospital.

CIRAS drew its data from the Research Patient Data Registry, a 25-year accumulation of 450 million diagnoses, medications, procedures, reports, and laboratory values from 1.8 million patients using MGH or Brigham and Women's Hospital.

CIRAS will also house all 300 million imaging studies performed at all Partners Healthcare member institutions, something beyond the capability of the RPDR.

Hirschorn said that CIRAS dramatically increases the research and educational potential of the RPDR. Cohorts can now be selected based on imaging characteristics not captured in the report. Disease trends can be found and traced in radiologic images.

One of the first main CIRAS users will be the Partners Human Genomics Research Project.

The system is designed to meet the needs of both researchers and those wishing to feed images to another device for processing. Therefore, two versions of each image are stored on the main archive server. For actual viewing, one copy is stored as a standard JPEG with moderate lossy compression.

Designers had to decide whether it was necessary to maintain separate copies of every image on the system's own storage, Hirschorn said. While it would have been less expensive to keep just a cache of recently requested images and request new ones as needed, this was deemed inappropriate due to the risk of interfering with clinical operations.

"If a researcher requests several TB of data at once, it may easily overwhelm one of the member institution's PACS servers," he said. "With an independent storage system, CIRAS data can be accessed at will beyond the capacity of its cache to keep up without causing any disruption to the PACS from which it came."

The main archive server has a primary storage capacity of 30 TB.

"It has yet to be determined if that 30 TB can be maintained simply through network attached storage or if a storage area network would be more advantageous," Hirschorn said.