Labeled leukocytes and sulfur colloid normally accumulate in bone marrow, and discordant labeled white cell activity without corresponding sulfur colloid uptake indicates infection [37]. Planar scintigraphy imaging modalities alone have relatively low spatial resolution and lack anatomic specificity. Nuclear medicine modalities are useful in cases where infection is multifocal or when the infection is associated with orthopedic hardware or chronic bone alterations from trauma or surgery. 3-phase Bone Scan and WBC Scan and Sulfur Colloid Scan Foot Combined labeled leukocyte and sulfur colloid bone marrow imaging is most useful when increased labeled leukocyte activity is secondary to altered bone marrow distribution, such as around joint prostheses [36]. In evaluating arthroplasties, positive bone scan and WBC uptake with no uptake on the bone marrow scan is considered positive for infection [38]. This modality may be helpful when significant metal hardware is present that would impair MRI or CT imaging. Planar scintigraphic imaging modalities have relatively low spatial resolution and lack anatomic specificity. Nuclear medicine modalities are useful in cases where infection is multifocal or when the infection is associated with orthopedic hardware or chronic bone alterations from trauma or surgery. FDG-PET/CT Whole Body FDG-PET/CT has potentially an important role in diagnosing deep soft-tissue infection and osteomyelitis and in differentiating neuropathic arthropathy [39,40]. The high resolution of FDG-PET/CT offers an advantage over single-photon emitting tracers, particularly when evaluating precise localization of radiotracer accumulation in bones of the distal forefoot, where the majority of diabetic foot infections occur [41]. Fused FDG-PET/CT allows correct differentiation between osteomyelitis and soft-tissue infection [42,43].
Suspected Osteomyelitis of the Foot in Patients with Diabetes Mellitus. Labeled leukocytes and sulfur colloid normally accumulate in bone marrow, and discordant labeled white cell activity without corresponding sulfur colloid uptake indicates infection [37]. Planar scintigraphy imaging modalities alone have relatively low spatial resolution and lack anatomic specificity. Nuclear medicine modalities are useful in cases where infection is multifocal or when the infection is associated with orthopedic hardware or chronic bone alterations from trauma or surgery. 3-phase Bone Scan and WBC Scan and Sulfur Colloid Scan Foot Combined labeled leukocyte and sulfur colloid bone marrow imaging is most useful when increased labeled leukocyte activity is secondary to altered bone marrow distribution, such as around joint prostheses [36]. In evaluating arthroplasties, positive bone scan and WBC uptake with no uptake on the bone marrow scan is considered positive for infection [38]. This modality may be helpful when significant metal hardware is present that would impair MRI or CT imaging. Planar scintigraphic imaging modalities have relatively low spatial resolution and lack anatomic specificity. Nuclear medicine modalities are useful in cases where infection is multifocal or when the infection is associated with orthopedic hardware or chronic bone alterations from trauma or surgery. FDG-PET/CT Whole Body FDG-PET/CT has potentially an important role in diagnosing deep soft-tissue infection and osteomyelitis and in differentiating neuropathic arthropathy [39,40]. The high resolution of FDG-PET/CT offers an advantage over single-photon emitting tracers, particularly when evaluating precise localization of radiotracer accumulation in bones of the distal forefoot, where the majority of diabetic foot infections occur [41]. Fused FDG-PET/CT allows correct differentiation between osteomyelitis and soft-tissue infection [42,43].