CAD program boosts productivity, enhances MR images to assist breast cancer evaluations

Color-coding highlights likely malignancies

Computer-aided detection has gained a foothold in x-ray mammography. Now a small company in Kirkland, WA, wants to extend this software genre to MR.

This latest software product, called CADstream, automates many of the time-consuming tasks necessary to analyze MR mammograms while color-coding tissues according to the likelihood of their malignancy. The product passed FDA review more than a year ago, but its developer, Confirma, only began marketing the product late last year. So far 11 sites are running CADstream. Four purchased the product in the last several months.

CADstream corrects for patient movement and registers the image, minimizing artifacts that can obscure lesions. Data can be reprocessed into maximum intensity projections or multiplanar reformations. They can also be subtracted to emphasize vascularity.

Most remarkable, CADstream plots vascular maps that indicate the flow of contrast media into the neovascular beds that grow around tumors. These maps are color-coded to indicate uptake and washout rates characteristic of normal anatomy or pathology.

"In areas of increased vascularity, there is increased blood flow and, therefore, increased flow of contrast agent," said Daniel Bickford, Confirma director of marketing and sales. "The rate of that contrast agent being washed in and out of any specific area of the breast is indicative of likely disease."

The different colors draw attention to specific lesions in the images. Red indicates the rapid uptake and quick washout most often associated with malignancy. Green indicates a plateau curve, a rapid rise in uptake that suddenly flattens. Blue indicates progressive uptake, which is associated with benign processes.

The colors are matched to quantitative thresholds present in the MR data, according to Bickford. Radiologists at the sites purchasing the software determine the thresholds.

"We allow radiologists to see the data that are already there and really dig into the details of those data without spending a lot of time," he said.

This color-coding scheme provides an unmistakable voxel-by-voxel report, which can prove invaluable. A breast MR exam may comprise a thousand images. Several studies a day can overwhelm a human interpreter. CADstream easily manages this flood of data.

"When you do breast MR, your brain gets saturated with images over time. But the computer doesn't get tired," said Dr. Bruce Porter, medical director of First Hill Diagnostic Imaging, an outpatient clinic in Seattle.

Porter uses CADstream to analyze three or four MR mammography patients daily.

"Several times it has detected lesions that, if I had been really tired and it was really late, I could conceivably have overlooked, if not for the fact that they were flagged as green or red," he said. "A red or green overlay on a lesion forces me to take a really hard look at it."

CADstream has come at a time of increasing interest in breast MR. Medicare reimburses for the procedure when used to diagnose, stage, or plan treatment for breast cancer patients. In mid-March, the National Cancer Institute awarded a three-year, $1.9 million grant to Alan Penn & Associates to develop a CAD system to assist radiologists interpreting MR images of the breast. Researchers from seven institutions, including the University of Pennsylvania, George Washington University, and University of Chicago will collaborate on the project.

Confirma hopes to make CADstream more widely available through a partnership with PACS developer Sectra Imtec of Sweden. Sectra has agreed to integrate Confirma's software into its PACS as a modular, add-on feature of the Sectra Clinical Solutions Network.

CADstream is Confirma's first commercial product. The company was founded six years ago intending to develop a family of such systems covering all types of cancer. The goal of those products was to stage the different types of cancer. This proved too ambitious for the start-up and strategists chose to focus on breast MR.

Confirma sells CADstream under licensing agreements that call for an upfront payment of $35,000 followed by per study payments of $120 each. Agreements are negotiable, Bickford said, and Confirma is prepared to offer discounts. The company is on track to meet its goal of having 70 CADstream systems installed by the end of this year. Most leads for new business come from CME conferences on breast imaging. The company has scheduled 14 such conferences in 2003.