The latest Radiology Business 100 survey of private radiology practices came out last month and the message is clear: size matters – in the present health care climate it isn't enough to merely hold your ground.

“Radiology practices have continued to grow, particularly at the top of the ranking,” noted the survey, which is conducted in partnership with the American Academy of Radiology.

Average sizes crept up from 52 full time equivalent (FTE) radiologists in 2015 to 53.5 in 2016. And the number of practices with over 65 practitioners rose from 20 in 2015 to 26 in the latest year.

To put that in perspective, noted Radiology Business, “in 2009, when we began ranking the 50 largest private radiology practices, there were eight.”

This is the ninth such survey conducted by the publication.

Topping the list are the same five players from last year. But they didn't rest on prior laurels — all added practitioners and had the largest growth, pointing to the trend toward size that is sweeping the health care industry in general.

Number one, as it was last year, is Radiology Associates of North Texas (RANT), Fort Worth. It now has 164 FTE radiologists, up 36 from the year before.

The rise was aided by the addition, in March, of Texas Neuroradiology and Radiological Consultants Association, according to a statement on its website. These are the fourth and fifth radiology practices to join Radiology Associates within the past 6 years. “In all, the combined group will read over 2.5 million exams each year,” RANT said in a statement at the time.

At number two, up from fifth place a year ago, was University Radiology in New Brunswick, New Jersey. It had 119 FTE practitioners, and ts merger with Bridgewater, New Jersey's Associated Radiologists, contributed 19 to that total.

Coming in third was Advanced Radiology Services, Grand Rapids, Michigan. It grew to 108 FTE practitioners from 106 a year ago.

Southwest Diagnostic Imaging, Phoenix, Arizona, maintained its fourth place from a year ago. It grew to 104 FTE radiologists this year from 101 last year.

Finally, at number five, was Radia, Lynwood, Washington. It grew to 102 FTE practitioner, up from 100 last year.

Buttressing the argument that size matters, reported Radiology Business, “Practices retained their previous year’s ranking only by adding radiologists. In other words, if a practice stood still, it slipped down the list. This was true in all practice-size cohorts.”

Biggest practices grew the most, “from 21 in 2015 to 26 in 2016 and the 35 to 49 FTE radiologists cohort (from 33 in 2015 to 37 in 2016) gained four practices. The number of practices with 50 to 65 radiologists declined significantly (from 25 in 2015 to 17 in 2016) — at least five of the eight stepped up to the largest category. The smallest size cohort dropped by one practice, from 21 in 2015 to 20 in 2016,” according to Radiology Business.

All groups but the under-35-sized practices saw a rise in median number of procedures. “The median number of studies performed by the largest practice-size cohort increased the greatest amount, from 1,385,000 in 2015 to 1,489,965 in 2016,” stated Radiology Business.

While the study did not reveal specific revenue data, in general, “the median revenue generated per radiologist took a significant dive, despite apparent but small increases in productivity. On the other hand, the average revenue per radiologist increased slightly among the 37 practices that shared their data with us. A significant drop in the median revenue-per-radiologist and a slight increase in the average revenue-per-radiologist in our group of 37 suggests that the revenue picture for large practices is better than the smaller practices in this group.”