(Business 2.0) – Magnetic Resonance Imaging, or MRI, revolutionized diagnostic medicine by allowing doctors to create detailed pictures of a patient's organs and tissues. The catch is that the huge machines typically weigh about a ton and cost as much as $2 million. Erez Golan, 33, and Eyal Kolka, 34, co-founders of Israeli startup TopSpin Medical have revolutionized MRI technology by radically reducing the size of the machines. Instead of sliding patients into a room-size behemoth, they've created a device so tiny it can be slipped into the patient.

"If MRI machines are like mainframe computers, I wanted to build a laptop," Golan says. Impossible, the duo was told by researchers at GE, Philips, Siemens, and Toshiba. But, Kolka says, "being an entrepreneur means you can't give up easily."

They didn't. In borrowed lab space at Hebrew University, Golan and three other physicists spent months perfecting their design for a tiny magnetic probe that can be inserted into a patient's arteries to search for heart-attack-causing plaque--a procedure that could help reduce the $221 billion America now spends on cardiac health care. By 2001 they had a working prototype of their mini MRI scanner. Clinical trials begin in Europe this year, and the $1,000 disposable device is expected to be released in 2005. -- MICHAEL V. COPELAND