Katrina Nesta Glazebrook MBChB, Presenter: Nothing to Disclose

Maria Shiung, Abstract Co-Author: Nothing to Disclose

Shuai Leng PhD, Abstract Co-Author: Nothing to Disclose

Naveen Srinivasa Murthy MD, Abstract Co-Author: Nothing to Disclose

Rickey Carter PhD, Abstract Co-Author: Nothing to Disclose

Cynthia H. McCollough PhD, Abstract Co-Author: Research Grant, Siemens AG

To demonstrate the feasibility of identifying monosodium urate (MSU) crystals using a conventional single source (SS) CT scanner with two consecutive scans and a non-rigid 3D registration algorithm using dual-source (DS) dual-energy (DE) CT as the reference standard.

After IRB approval, patients undergoing clinically indicated DSDE-CT scans for identification of MSU crystals in or around joints of the upper and lower extremities were recruited on the same day to have SS CT scans with an 80 kV scan, immediately followed by a 140 kV scan. The 2 scans were co-registered with the 3D non-rigid anatomic registration software. DE material composition analysis was then performed on the serial acquired SS DECT scans and the similtaneously acquired DS DECT scan. Four musculoskeletal radiologists randomly evaluated the SS or DS DECT scans of the patients with 2 readings, performed 4 weeks apart, to assess for the presence or absence of green pixilation representative of MSU crystal deposition. Kappa estimates were calculated for the 4 readers.

A total of 40 patients were evaluated (13 female and 27 male, age range 40 to 82). All 4 readers classified the DS DECT as positive for MSU crystals in 14 patients and negative in 25 patients with 3 of the 4 readers classifying one additional patient as negative. The Kappa statistics for each reader and for the pooled readers showed substantial agreement between the DS and SS techniques (pooled kappa = 0.90 (0.83-0.97 95% confidence interval).

The results of this study indicate that consecutively acquired SS DECT datasets plus 3D non-rigid motion registration can reliably identify MSU crystals with high agreement to the reference standard of DS DECT.

The ability to utilize SS CT scanners to identify MSU crystals in and around joints will significantly increase the availability of this non-invasive diagnostic test for patients with suspected gout.

Glazebrook, K, Shiung, M, Leng, S, Murthy, N, Carter, R, McCollough, C, Feasibility Study to Estimate the Performance of Single-source Dual Energy CT Scans and Non-rigid 3D Anatomic Registration for Identifying Monosodium Urate Crystals.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14015279.html