Double Thoracic CT Used Appropriately Despite Doubts

September 2, 2014

Mainstream media may report CT overuse, but double thoracic CT is used appropriately, study says.

A new evaluation of Medicare claims data showed that combined thoracic computed tomography (CT) scans - taken with contrast and without contrast in the same day -account for less than 5 percent of CT scans, indicating that combined CT is not being overused by radiologists.  

In 2011, the New York Times published an article titled, “Medicare Claims Show Overuse for CT Scanning” in which it reported that 2008 Medicare claims data showed that some hospitals were performing two chest CTs in one day in a large number of their Medicare chest patients, increasing radiation burden and cost.

In this study, David C. Levin, MD, of Thomas Jefferson University Hospital, and colleagues wanted to use a large national database to determine if double thoracic CT scan use is widespread, and track if its use has increased or decreased in recent years. They published the results of their analysis in the Journal of the American College of Radiology.

Levin and colleagues looked at data from 2001 to 2011 taken from the Medicare Part B Physician/Supplier Procedure Summary Master Files. They looked at procedures coded for thoracic CT with contrast, without contrast and without plus with contrast.

“The main findings were that the use of combined chest CT scans was generally quite low to begin with, and that it has been dropping even further in the last few years,” Levin told Diagnostic Imaging.[[{"type":"media","view_mode":"media_crop","fid":"27445","attributes":{"alt":"","class":"media-image media-image-right","id":"media_crop_143212588393","media_crop_h":"0","media_crop_image_style":"-1","media_crop_instance":"2676","media_crop_rotate":"0","media_crop_scale_h":"0","media_crop_scale_w":"0","media_crop_w":"0","media_crop_x":"0","media_crop_y":"0","style":"height: 113px; width: 151px; border-width: 0px; border-style: solid; margin: 1px; float: right;","title":" ","typeof":"foaf:Image"}}]]

Looking at all three codes together, from 2001 to 2007, data showed there was an increase in the utilization of these scans per 1,000 beneficiaries that peaked at 99.6 per 1,000. However, after 2007, data showed small declines in the use of these scans through 2011 when there was a rate of 91.3 per 1,000 beneficiaries.

“These changes were not influenced by the introduction of any new codes; the code for CT angiography of the thorax (71275) had been introduced in 2001 and was therefore in existence for the entire period of the study (that code was not included in this analysis),” the researchers clarified.

The researchers also looked at just the combined CT scans code and found data consistent with the three combined codes. From 2001 to 2007, use of the combined code increased rapidly, showing a growth rate of 10.4 percent over that period of time. Beginning in 2007, use of the code decreased through 2011, showing an annual compound rate of change of –10.4 percent.

Looking at these codes as a percentage of all thoracic CTs conducted, combined scans made up about 6 percent of scans from 2001 to 2006, but only 4.2 percent of scans in 2011.

“Radiologists have done the right thing by their patients. Even though they could increase their revenues by doing combined scans, they have kept the use of these scans to a minimum,” Levin said. “Moreover, it appears that in the last few years, radiologists have exercised even more vigilance and have decreased their use even further.”