St. Jude Medical Inc. said late Wednesday that it has agreed to buy an imaging company called LightLab Imaging Inc. for about $90 million in cash.

The Little Canada-based medical technology company said Massachusetts-based LightLab pioneered development of optical coherence tomography (OCT), a high-resolution coronary imaging technology that helps doctors treat heart disease.

Earlier this month LightLab, a subsidiary of Goodman Co. Ltd., received Food and Drug Administration clearance for the first OCT products to be available in the United States.

St. Jude said it expects the OCT platform to contribute an additional $20 million in revenue to its cardiovascular business in the second half of this year. The OCT market is expected to grow at a double-digit annual rate over the next five years.

The transaction is expected to close by the end of the second quarter. St. Jude said the acquisition does not change its outlook for 2010.