Radiographic imaging in osteomyelitis: the role of plain radiography, computed tomography, ultrasonography, magnetic resonance imaging, and scintigraphy

Abstract

The diagnostic imaging of osteomyelitis can require the combination of diverse imaging techniques for an accurate diagnosis. Conventional radiography should always be the first imaging modality to start with, as it provides an overview of the anatomy and the pathologic conditions of the bone and soft tissues of the region of interest. Sonography is most useful in the diagnosis of fluid collections, periosteal involvement, and surrounding soft tissue abnormalities and may provide guidance for diagnostic or therapeutic aspiration, drainage, or tissue biopsy. Computed tomography scan can be a useful method to detect early osseous erosion and to document the presence of sequestrum, foreign body, or gas formation but generally is less sensitive than other modalities for the detection of bone infection. Magnetic resonance imaging is the most sensitive and most specific imaging modality for the detection of osteomyelitis and provides superb anatomic detail and more accurate information of the extent of the infectious process and soft tissues involved. Nuclear medicine imaging is particularly useful in identifying multifocal osseous involvement.

Keywords: Osteomyelitis; computed tomography; magnetic resonance imaging; nuclear medicine; ultrasound.

Figure 1

Chronic osteomyelitis: role of sinography. (A) Anteroposterior view of the right femur demonstrates several radiodense, sharply marginated foci within lucent cavities suggestive of sequestration. (B) Oblique view showing retrograde opacification of a sinus tract defining the course and extent of the fistula and confirming the communication with an abscess in the bone.

Figure 2

Osteomyelitis due to direct implantation in a young patient. (A) Lateral radiograph of the left femur showing cortical irregularities and soft tissue swelling with increased density and obliteration of tissue planes. (B, C) Coronal and axial T1-weighted MRI scans show extensive soft tissue abscesses (arrows) with associated cortical irregularities (black arrow) and abnormal areas of high and low signal within the medullary cavity indicative of chronic osteomyelitis. (D) Transverse US panoramic scan of the thigh showing displacement of the soft tissues due to a huge staphylococcal abscess adjacent to an irregular femoral cortex (arrow). (E) Long axis view of the femur displaying periosteal lifting (arrow). Power Doppler highlights hyperemia around the periosteum.

Figure 3

Hematogenous osteomyelitis: Brodie's abscess. (A, B) Anteroposterior and lateral radiographs of the distal tibia outline a typical appearance of an abscess. Observe the well-circumscribed, oval, and radiolucent lesion with surrounding sclerosis extending to the closing joint (arrows). (C) Axial T1-weighted MRI scan showing an intramedullary hypointense, lobulated lesion, with a well-defined outline. (D, E) Coronal T1-weighted and T2 fat-suppressed MRI scans showing marrow involvement. (F) Sagittal T2 fat-suppressed MRI scan displaying hyperintense circular and well-defined lesion. The appearance is that of a Brodie's abscess.