Mayo Clinic Study Finds CT Scans Can Help Detect Gout Cases Traditional Tests Miss

Saturday, November 05, 2011

CHICAGO — X-ray images known as CT scans can help confirm gout in patients who are suspected of having the painful condition but receive negative results from traditional tests, aMayo Clinicstudy has found. The type of CT scan analyzed, dual-energy computed tomography, also is valuable for diagnosing people who cannot be tested with the typical method of drawing fluid from joints, researchers found. The study is being presented at theAmerican College of Rheumatologyannual scientific meeting in Chicago.

VIDEO ALERT:Embargoed audio and video of Dr. Bongartz discussing the study is posted on theMayo Clinic News Blog. The password is ACR.

Gout— the buildup of uric acid crystals in and around joints, causing inflammation and painful, potentially disabling flare-ups — has historically been portrayed as a disease of the wealthy, but it afflicts people from all walks of life. Men are more likely to develop gout, but women's risk rises aftermenopause, when their uric acid levels approach those of men. Treatment usually involves medication and dietary changes.

Physicians traditionally check for gout by using a needle to draw fluid from affected joints and examining the fluid for uric acid crystals. Dual-energyCT scanswere recently modified to detect the crystals, and the study found the scans "very accurate" in identifying patients with gout, says lead researcherTim Bongartz, M.D.,arheumatologistat Mayo Clinic in Rochester, Minn.

"We wanted to really challenge the new method by including patients who were only a few days into their first flare of gout," Dr. Bongartz says.

Dr. Bongartz notes that CT scans are significantly more expensive than the standard test for diagnosing gout. He also cautions that, while highly accurate overall, in one subgroup of patients studied — those with very acute gout — the CT scan failed to identify 30 percent of cases. The new tool is most helpful when joint fluid cannot be obtained or the fluid analysis comes back negative even when gout is strongly suspected, he says.

Dr. Bongartz will discuss his study, ACR Presentation 1617, at 2:30 p.m. Monday, Nov. 7, in Room W183c at theMcCormick Place Convention Center. He will be available for media questions and a briefing at 8:30 a.m. Tuesday, Nov. 8, in the press conference room, W175C.

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