Seeking guidance from the stars

16 May 2007

What can astronomers and medical imaging specialists learn from each other? A new project at Harvard University aims to find out.

You wouldn't expect to find an astronomer poring over the results of a PET/CT scan. Neither would you expect to see a medical-imaging specialist scrutinizing radio-telescope images of star formation. Yet researchers from Harvard University believe it is high time that these two apparently disparate fields were brought closer together.

The Astronomical Medicine (AstroMed) project is being run from Harvard's Initiative in Innovative Computing (IIC), an interdisciplinary R&D centre. Project organizers hope to use the combined knowledge of scientists from Harvard Medical School and the Harvard-Smithsonian Center for Astrophysics to advance the state-of-the-art in both medical imaging and astronomy.

Astronomy and medical imaging have a surprising amount in common, according to AstroMed's project manager Michael Halle, principal of the Surgical Planning Laboratory at Brigham and Women's Hospital in Boston, US. Both fields are highly image-intensive and often require different types of data to be fused together. Practitioners must also sift through large amounts of information, sorting useful structures from features that are of no interest at all.

To date, each discipline has developed its own set of tools for analysing the respective banks of imaging data. Yet essential similarities between the tasks suggest scope for a more symbiotic relationship. "Finding features in an image of a galaxy is in many ways similar to looking for a tumour inside the brain," Halle tould medicalphysicsweb.

He has identified two broad areas where methods developed in astronomy could feed into medical imaging. The first is the development of techniques to reduce background noise on images. Astronomers face this problem when trying to analyse very distant stars in any detail. Similar techniques may be of benefit to examinations such as X-ray mammography, where it can be difficult to pick out the subtle signs of early-stage abnormalities.

Blue-sky thinking

Medical-imaging researchers could also learn from astronomers' expertise in monitoring the "processing pipeline" that raw data from satellites must pass through. Careful tracking of how data has been manipulated allows astronomers to understand differences between data acquired today from that generated, say, three or four years ago.

Halle explained: "This idea of data provenance is something that people in medical-imaging research have identified as being very important, but it is only beginning to be developed as far as standards are concerned. We hope that we can transfer information on data provenance from astronomy back to medical imaging, and maybe have a framework that really supports broader ideas from both fields."

All of this will have to wait for the time being, though. AstroMed team members will first concentrate on the other aspect of the relationship - that is, showing how technology used in hospitals could help make it easier to study the stars.

Researchers at Brigham and Women's Hospital, for example, have developed software tools that turn different streams of 2D medical-imaging data into interactive 3D models. These tools are being modified so that astronomers can visualize star formation in dusty gas clouds in the Milky Way in 3D too.

"There is a long history of data analysis in astronomy, but the tools for visualizing multidimensional data quickly really haven't developed anywhere near as much as they have in medical imaging," Halle said. "Astronomers seldom look at their data in 3D, whereas doing a 3D reconstruction of a patient's scan data is performed quite commonly, often right on the scanner itself."

A review of AstroMed's progress will be made in about two years' time. Halle is hopeful that by this stage medical-imaging and astronomy researchers involved with the project will have become familiar with the challenges and solutions from each other's fields. "At that point, we can talk about how we can work together to improve the lot of medical imaging and astronomy," he added.