By: Catherine Carrington

Demand for CT has without question grown steadily over the last decade. In 1991, at about the time spiral CT was introduced, patients underwent an estimated 16.6 million CT scans in the U.S., according to technology research firm IMV Medical Information Division. By 1996, that number had grown to 22.6 million, and by 2001, to 39.6 million. The increase represents an average growth rate of about 15% per year.

Shipments of CT scanners have climbed steadily over the years as well. The National Electrical Manufacturers Association forecasts continued strong sales in 2003 and 2004, ranging from about 350 to 400 units each quarter.

A cloudy economy and pressure to contain healthcare costs have moderated, but not stalled, sales momentum, a claim not all imaging modalities can make. Additional growth will likely be at least modest. Shipments of CT scanners are expected to top out at 1419 for 2002, up just a notch from a record high of 1387 in 2001. Projections for 2003 and 2004 peg CT sales at 1483 and 1526 units, respectively.

Technological innovation appears to have propelled the market. In 1999, only about 20% of CT scanners had multidetector capability, but by 2001 that number had grown to about 50%. Multidetector scanners will account for about half of sales through 2003, IMV predicted.

Not unexpectedly, a growing number of users are taking advantage of advanced CT technology to perform cutting-edge procedures such as virtual colonoscopy. In 2001, only about 5% of CT sites offered virtual colonoscopy but, according to IMV's estimates, an additional 13% will begin to offer the procedure in the coming year.