Hologic Inc., the Bedford-based supplier of diagnostic tools for women, announced today that it has reached an agreement to buy Sentinelle Medical Inc., a privately-held Toronto company, for $85 million.

Sentinelle Medical provides Magnetic Resonance Imaging (MRI) breast coils, tables and visualization software.

In addition to the purchase price, the deal calls for a two-year contingent earn out, payable in cash installments equal to a multiple of the incremental revenue growth in Sentinelle Medical’s business in the two years following the closing.

The transaction is expected to close during the third quarter and is subject to customary closing conditions, including Sentinelle Medical stockholder approval and Canadian judicial approval.

In a press release, Hologic president and CEO Rob Cascella said, “The agreement to acquire Sentinelle Medical is a further example of our strategy to maintain a leadership position in women’s healthcare. Magnetic Resonance (MR) is rapidly becoming a standard of care for breast cancer screening of women indicated as having a high risk of developing the disease. This acquisition should further strengthen our comprehensive portfolio of product offerings in the areas of breast cancer detection and intervention.”

Sentinelle Medical’s revenue in calendar 2009 was approximately $15 million. Hologic expects this acquisition to be neutral to earnings in fiscal 2011, absent the amortization of intangibles related to the transaction and other acquisition-related charges.

In April, Hologic won $15 million from the U.S. military for radiology systems, according to the U.S. Department of Defense.