Dual-Energy Computed Tomography Useful for Diagnosing Gout

VBCR - June 2013, Volume 2, No 3 - Gout

By Rosemary Frei, MSc

Montreal, Quebec—Dual-energy computed tomography (DECT) has value in gout diagnosis and management, according to a presentation at the Canadian Association of Radiologists’ 2013 annual meeting.

DECT involves the use of 2 x-ray sources, each at a different energy level, and 2 banks of detectors 90 degrees apart. The radiation dose is the same as for regular computed tomography. The result is 2 sets of images that can be compared to produce color-coded depictions of ligaments, tendons, bone edema, and uric acid (Figures 1 and 2).

Paul Mallinson, MBChB, a radiology fellow at Vancouver General Hospital, works on DECT in gout with Savvas Nicolaou, MD, an assistant professor of diagnostic radiology at the University of British Columbia. DECT is noninvasive and, therefore, has advantages over the classic test, which involves aspiration of the affected joint to determine whether monosodium urate crystals and/or infection are present.

“That means the patient has to have a needle in a joint, which is a little painful and has potential complications, plus you have to limit the number of joints you test because the patient won’t find it acceptable to have multiple joints aspirated,” Dr Mallinson explained.

Patients who are suspected to have gout undergo DECT imaging of the hands and wrists, followed by the elbows, the knees, the feet, and the ankles. Previous studies have shown the technique has a sensitivity ranging from 84% to 100% and specificity ranging from 79% to 100% (AJR Am J Roentgenol. 2012;199:S78-S86).

“You can look for gout in the joint or joints you think are symptomatic, and you can also look at other joints to see if there are gout crystals even though gout hasn’t become clinically apparent in those joints yet,” said Dr Mallinson in explaining other advantages of DECT. In addition, patients can be reimaged after urate-lowering therapy to determine whether the treatment has been effective.

The images are displayed on a specialized workstation as 3-plane cross-sectional and 3-dimensional images. The urate is shown as green areas and the calcium of the bones is blue (Figures 1 and 2).

There can be artifacts that appear green on the images that are not actually gout, but DECT users quickly learn to differentiate these from true gout, Dr Mallinson said. Tissues that commonly produce artifacts are the nails and nail beds in the feet, and areas where there is thickened skin or areas of proximate skin, such as when toes are pressed together.

Related Items
Increased Risk for Erectile Dysfunction Among Men with Gout
Sophie Granger
VBCR - August 2017, Vol 6, No 3 published on August 23, 2017 in Gout
Lesinurad Added to Allopurinol Improves Outcomes in Patients with Gout
Anne Rowe
VBCR - June 2017, Vol 6, No 2 published on June 29, 2017 in Gout
Allopurinol May Reduce Risk for Cardiovascular Events in Patients with Gout and Diabetes
Rebecca Bailey
VBCR - June 2017, Vol 6, No 2 published on June 29, 2017 in Gout
Patients with Gout and Poorly Controlled Comorbid Osteoarthritis Can Benefit from Earlier Treatment
Leslie Wyatt
VBCR - April 2017, Vol 6, No 1 published on May 3, 2017 in Gout
Patient Tip: 5 Tips for Easing or Preventing Gout Attacks
VBCR - December 2016, Vol 5, No 6 published on January 5, 2017 in Gout
EULAR Updates Its Gout Guidelines with New Treatment Recommendations
Alice Goodman
VBCR - August 2016, Vol 5, No 4 published on August 25, 2016 in Gout
Better Disease Control Needed in Patients with Gout
E. K. Charles
VBCR - April 2016, Vol 5, No 2 published on April 29, 2016 in Gout
Better Understanding of Patients with Gout Needed
Alice Goodman
VBCR - February 2016, Vol 5, No 1 published on March 15, 2016 in Gout
New Gout Classification Criteria Released
Rosemary Frei, MSc
VBCR - December 2015, Volume 4, No 6 published on December 15, 2015 in Gout
Use of Colchicine Reviewed
Rosemary Frei, MSc
VBCR - February 2015, Volume 4, No 1 published on March 5, 2015 in Gout
Last modified: May 21, 2015
  • Rheumatology Practice Management
  • Lynx CME
  • American Health & Drug Benefits
  • Value-Based Cancer Care
  • Value-Based Care in Myeloma
  • Value-Based Care in Neurology