You could consider Minnesota medical technology companies Acist Medical Systems and HLT to be sisters — but certainly not twins.

They share the same founder and chief scientific officer, Dr. Robert F. Wilson. And they have the same president and chief operating officer, Tom Morizio. They were even "adopted" by the same Italian parent company, Bracco. But what the companies make and where they are in their maturation as moneymakers is about as different as siblings can be.

Acist, based in Eden Prairie, makes imaging technology designed to help cardiologists better see what is going on inside the chests of their patients during procedures. The company reported $150 million in revenue in 2013.

HLT, a Maple Grove company that Wilson started in 2002, is developing a transcatheter heart valve that still is probably years away from U.S. regulatory approval.

Different companies, different products, but a shared "commitment to setting new standards in the cardiology industry," Morizio said in a recent interview. "Diagnostics is our strength."

For now, Acist is leading the charge in the R&D arena, and on the balance sheet. The company recently won U.S. Food and Drug Administration and European approval of its "Rapid Exchange" fractional flow reserve system that uses fiber optics to help doctors pinpoint the most damaging blockages in coronary arteries. The idea is to discover where to more efficiently place stents that keep the arteries open and blood flowing. The company started selling the technology last month.

"This really allows you to expand the use of FFR [fraction flow reserve]," Wilson said of the thin, hollow tube that the doctor snakes into a patient's artery and then uses light to quickly give a better idea of where to clear clogs.

The company's injector technology, developed by Wilson decades ago, has helped provide sharper views of the heart during cardiology procedures. And, recently, Acist purchased a California company that produces an intravascular ultrasound to better see inside the circulatory system.

Morizio said Acist's technology now is in 40 percent of all catheter labs worldwide.

Wilson, a longtime faculty member at the University of Minnesota, started Acist in 1991, motivated as a cardiologist who wanted better tools to help him do his job. Over the years, the company raised about $29 million in capital, including $3 million from angel investors, $4 million from Bracco and the rest from venture capitalists. In 2001, he sold the company to the Bracco Group, a private multinational company based in Italy, but he retains a strong role in the firm.

He launched HLT soon after, again with the idea of coming up with a better replacement aortic valve that could be placed into a patient's heart without cracking open the chest. HLT is still awaiting FDA and European approval for clinical trials for its valve, which Wilson said is designed to better fit irregular shaped aortic valves and will allow doctors to reposition it during the procedure. Wilson sold HLT to Bracco in 2010.

Acist has more than 300 employees in the U.S. and around the world. HLT has 70.

Wilson acknowledged that the invention bug has bitten him pretty hard. He said he hopes he is becoming "a serial entrepreneur."

"I make stuff for myself. They are things that I want," he said of his beginnings as an inventor and company builder. "Usually, when you are developing something, there is a moment when you realize: 'I got it!' "

He, Morizio and Bracco are banking on expectations that other doctors will find this stuff just "as cool and useful and unique."

James Walsh • 612-673-7428