The Academy of Radiology Research has resorted to a creative tactic in a bid to halt the decline in public funding for science: It showed Congress a picture of how much the nation earns from the government’s research dollar.

Every $100 million invested in research by the National Institutes of Health, according to the R&D consulting firm Battelle, generates almost six patents. At the National Science Foundation $100 million generates more than 10. At the National Institute of Biomedical Imaging and Bioengineering — which finances research in radiology — it produces almost 25 patents. And these patents sparked $578.2 million worth of additional R&D further downstream.

“N.I.H. research has helped lower the burden of disease, and people in both parties recognize its importance,” said Jonathan Lewin, chairman of the department of radiology at Johns Hopkins University and head of the academy of radiology. “We decided to look at the economic value of our research to make the argument about this value, too.”

Radiologists hope this sort of analysis could help prioritize public funding in a tight budget era: National Institutes of Health budgets are almost 20 percent smaller than they were 10 years ago.