Companies that develop AI-driven medical imaging systems collectively received nearly $580 million in funding in 2018, according to a recent report from healthcare research firm Signify Research.

AI has become a popular focus in medical imaging innovation, with over 120 start-ups adamantly working to create advancements in the field. Since 2014, investors have contributed more than $1.2 billion to these companies, and funding levels are double what was reported in 2017.

According to the report, the number of early-stage (i.e. Angel Seed and Series A) investments has dropped since 2015-2016 after the “peak of new market entrants.” 2018 was the year of later-stage (Series B and up) investments, although the number of early-stage contributions was slightly higher than the later stage ones. For 2019, Signify predicts that investors will give to more established companies that produce AI-based medical imaging technology and make fewer early stage investments.

United States-based HeartFlow and VoxelCloud were the two most funded companies, receiving $476.6 million and $80.5 million respectively, and China-based Infervision came in third with $73.1 million in investments. The report found that on average, companies received $14.4 million.  Asian companies made up 42 percent of the $340 million in investments last year (not counting HeartFlow’s $240 million in Series E round funding)