Abstract
1005
Learning Objectives 1. Highlight the role of nuclear medicine techniques in the detection of inflammation. 2. Describe the procedure of imaging the feet using SPECT/CT. 3. Highlight the major challenges of this procedure, present image examples and discuss study interpretation 4. Gain an understanding of the clinical utility of this technique.
Osteomyelitis (OM) is a serious complication of deep ulcers in the diabetic foot. Its diagnosis is usually challenging. The only method specific for inflammation detection is scintigraphy with labeled leukocytes, and it is helpful in the differential diagnosis. Scintigraphy provides information about the presence of inflammation, but distinguishing cellulitis from OM is difficult. Hybrid imaging (SPECT/CT) is very useful in this setting. We omit the three-phase bone scan and, instead, perform a three-phase leukocyte scan (with Tc-99m labeled monoclona antibody). The early phase is used to assess blood flow and tissue perfusion which is useful in the differential diagnosis of Charcot foot. SPECT/CT imaging is performed at the time of the late phase of leukocyte scintigraphy several hours post injection using a special holder to exclude foot motion. Image fusion of leukocytes SPECT and CT allows precise localization of inflammation. If the focal accumulation of leukocytes localizes to a bony structure on CT, OM can be confirmed. The challenge of interpretation is the presence of Charcot foot, where leukocytes can also accumulate. Bone marrow scan with colloids could be performed to distinguish this. SPECT/CT is a very useful imaging method for the diagnosis of OM in patients with diabetic foot syndrome. Scintigraphy with labeled leukocytes detects the presence of inflammation and CT helps in its precise localization, thus obviating the need for bone scintigraphy.
Research Support This work was partially supported by the Research Program of the Czech Ministry of Education, Youth and Sports No. MSM002162081