Rajan Puri MD, Presenter: Nothing to Disclose

Mark E. Schweitzer MD, Abstract Co-Author: Nothing to Disclose

Janice Guilford, Abstract Co-Author: Nothing to Disclose

Michael Barry Mechlin MD, Abstract Co-Author: Nothing to Disclose

The baseline scintographic examination for the presence of orthopaedic infections is a triple phase bone scan. In the last two decades this has been supplemented by Indium labelled white blood cell scan to increase specificity. Technetium-99m-Tc fanolesomab (Tc-F) as an in vivo white blood cell imaging agent has the potential to provide flow images as well as delayed high specificity static images. Consequently, we performed a pilot study on the use of flow imaging with Tc-F for orthopaedic infections.

Twelve patients were prospectively evaluated. Following the intravenous administration of 20 millicuries of Tc-labelled fanolesomab flow images were obtained immediately. Forty frames, three seconds per frame was obtained followed by a blood pool image. The patient returned 60-90 minutes later for delayed images. The images were intrepreted in three separate reading sessions blinded to the clinical side in isolation without reviewing other scintographic or radiographic studies nor the delayed Tc-labelled images. Flow images were evaluated for assymetric flow only. In session I, the flow images were reviewed in isolation. In session II, the delayed images only in isolation. In session III, the flow and delayed images together. Accuracy, sensitivity, specificity, positive predictive value and negative predictive value were calculated for each of the sessions and statistically compared. Criteria for osteomyelitis was a)blood culture, b)bone biopsy, and c)absence of response to two weeks of intravenous antibiotic therapy.

Flow images alone using Tc-99m labelled antibody rendered the following results: Sensitivity: 1.0; Specificity: 1.0; PPV: .625; NPV: 1.0; Accuracy: .70 Results of Flow Images read together with Delayed were identical to flow alone. Results of Delayed Alone were: Sensitivity: .80; Specificity: .20; Positive predictive value: .50; Negative predictive value: .50; Accuracy: .50

Technetium-99m-Tc fanolesomab not only shows promise as a static imaging agent for musculoskeletal infections but can be supplemented by flow images to provide additional diagnostic information. In fact, the flow data in this small series was as useful as the static data.

Puri, R, Schweitzer, M, Guilford, J, Mechlin, M, The Use of Flow Imaging as an Adjunct to Technetium-99m-Tc Fanolesomab.  Radiological Society of North America 2005 Scientific Assembly and Annual Meeting, November 27 - December 2, 2005 ,Chicago IL. http://archive.rsna.org/2005/4417873.html