MRI with or without enhancement is a good modality to identify other potential sources of pain in this variant, such as soft-tissue infections, tumors and abscesses, early neuropathic arthropathy, or subtle fractures. Normal marrow signal reliably excludes osteomyelitis [20]. Positive cases of osteomyelitis demonstrate decreased T1-weighted bone marrow signal and increased signal on fluid-sensitive sequences [21,22]. Some authors suggest increased T2-weighted bone marrow signal may represent early osteomyelitis or be a predictor of later development of osteomyelitis, even in the setting of a normal T1-weighted signal [2]. MRI with or without enhancement is often the modality of choice in this variant because of its high sensitivity for osteomyelitis [23-25]. MRI with or without IV contrast can detect the earliest findings of neuropathic arthropathy, such as marrow edema and trabecular microfractures [17,26]. A negative MRI indicates that acute neuropathic arthropathy is unlikely [27]. MRI may be limited by artifact secondary to orthopedic hardware. 3-phase Bone Scan Foot The 3-phase bone scan is sensitive but not specific in differentiating osteomyelitis from a neuropathic foot since both processes cause increased osteoblastic activity [30]. Pathologies with high bone turnover, such as fracture, neuroarthropathy, malignancy, or recent surgery, may result in a positive scan in the absence of infection. A negative bone scan excludes infection with a high degree of certainty [31]. 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.
Suspected Osteomyelitis of the Foot in Patients with Diabetes Mellitus. MRI with or without enhancement is a good modality to identify other potential sources of pain in this variant, such as soft-tissue infections, tumors and abscesses, early neuropathic arthropathy, or subtle fractures. Normal marrow signal reliably excludes osteomyelitis [20]. Positive cases of osteomyelitis demonstrate decreased T1-weighted bone marrow signal and increased signal on fluid-sensitive sequences [21,22]. Some authors suggest increased T2-weighted bone marrow signal may represent early osteomyelitis or be a predictor of later development of osteomyelitis, even in the setting of a normal T1-weighted signal [2]. MRI with or without enhancement is often the modality of choice in this variant because of its high sensitivity for osteomyelitis [23-25]. MRI with or without IV contrast can detect the earliest findings of neuropathic arthropathy, such as marrow edema and trabecular microfractures [17,26]. A negative MRI indicates that acute neuropathic arthropathy is unlikely [27]. MRI may be limited by artifact secondary to orthopedic hardware. 3-phase Bone Scan Foot The 3-phase bone scan is sensitive but not specific in differentiating osteomyelitis from a neuropathic foot since both processes cause increased osteoblastic activity [30]. Pathologies with high bone turnover, such as fracture, neuroarthropathy, malignancy, or recent surgery, may result in a positive scan in the absence of infection. A negative bone scan excludes infection with a high degree of certainty [31]. 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.