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]. The high resolution can delineate the anatomic extent of osteomyelitis and assist in surgical planning [29]. 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. In the setting of deep soft-tissue ulceration, positive uptake in the adjacent bone is highly suggestive of osteomyelitis. 3-phase Bone Scan and WBC Scan Foot The combined bone scan and labeled leukocyte scan (In-111 or Tc-99m) markedly improves specificity in the nonmarrow-containing skeleton when there has been previous surgery, radiographs are abnormal, or when any other cause for bone remodeling is present [32]. It can be useful for distinguishing true WBC accumulation secondary to osteomyelitis from nonspecific WBC uptake that is seen in neuropathic joint [32,33]. Planar scintigraphic imaging modalities alone have relatively low spatial resolution and lack anatomic specificity.
Suspected Osteomyelitis of the Foot in Patients with Diabetes Mellitus. 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]. The high resolution can delineate the anatomic extent of osteomyelitis and assist in surgical planning [29]. 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. In the setting of deep soft-tissue ulceration, positive uptake in the adjacent bone is highly suggestive of osteomyelitis. 3-phase Bone Scan and WBC Scan Foot The combined bone scan and labeled leukocyte scan (In-111 or Tc-99m) markedly improves specificity in the nonmarrow-containing skeleton when there has been previous surgery, radiographs are abnormal, or when any other cause for bone remodeling is present [32]. It can be useful for distinguishing true WBC accumulation secondary to osteomyelitis from nonspecific WBC uptake that is seen in neuropathic joint [32,33]. Planar scintigraphic imaging modalities alone have relatively low spatial resolution and lack anatomic specificity.