Abstract
Various imaging techniques may be employed in the investigation of suspected bone and joint infections. These include ultrasound, radiography, functional imaging such as positron emission tomography (PET) and nuclear scintigraphy, and cross-sectional imaging, including computed tomography (CT) and magnetic resonance imaging (MRI). The cross-sectional modalities represent the imaging workhorse in routine practice. The role of imaging also extends to include assessment of the anatomical extent of infection, potentially associated complications, and treatment response. The imaging appearances of bone and joint infections are heterogeneous and depend on the duration of infection, an individual patient's immune status, and virulence of culprit organisms. To add to the complexity of radiodiagnosis, one of the pitfalls of imaging musculoskeletal infection is the presence of other conditions that can share overlapping imaging features. This includes osteoarthritis, vasculopathy, inflammatory, and even neoplastic processes. Different pathologies may also coexist, for example, diabetic neuropathy and osteomyelitis. This pictorial review aims to highlight potential mimics of osteomyelitis and septic arthritis that are regularly encountered, with emphasis on specific imaging features that may aid the radiologist and clinician in distinguishing an infective from a noninfective aetiology.
Highlights
Osteomyelitis is defined as bone inflammation due to infection whilst septic arthritis is defined by infection within a joint [1]
Imaging plays a crucial role in the diagnosis of infection, assessing disease extent, associated complications, planning biopsy sites, and monitoring treatment response. e various imaging tools employed include radiography, ultrasound, computed tomography (CT), and functional studies including nuclear scintigraphy, white cell scan, and positron emission tomography (PET)
Magnetic resonance imaging (MRI) Artefact: Failure of Fat Suppression. e failure of fat suppression on MRI, manifesting as increased fluid-signal towards the extremities of the scan field, or in presence of metalware which can alter the uniformity of the magnetic field, is a potential artefactual pitfall. is can be distinguished from pathology, as the adjacent subcutaneous fat will be involved or incompletely suppressed (Figure 13)
Summary
Osteomyelitis is defined as bone inflammation due to infection whilst septic arthritis is defined by infection within a joint [1]. Bone and joint infections have a variable clinical presentation ranging from acute sepsis to insidious onset of pain, with or without fever Laboratory results such as white cell count, C-reactive protein, and erythrocyte sedimentation rate are often, but not always, abnormal. In the event of discordant clinical and imaging information, where there is a high clinical index of suspicion for infection despite negative initial imaging results, repeat imaging is important as imaging findings may lag behind clinical manifestations by up to 2 weeks [6] (Figure 3). With atypical organisms such as tuberculous osteomyelitis, systemic manifestations may not be as florid. There is a marrow oedema signal on both sides of the articular surface, often with an accompanying joint effusion and synovial enhancement, these features are not as specific [7] (Figure 3)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
