Study designs of evaluations included in the review
Studies were only included if at least one site with the disease and one without were identified by the reference standard.
Specific interventions included in the review
Studies of MRI were eligible for inclusion. The majority of studies considered a lesion in the bone was positive on MRI if it showed focally decreased marrow signal intensity in T1-weighted images and a focally increased signal intensity in fat-suppressed T2-weighted or short tau inversion recovery images. Some studies also evaluated other signs known as secondary signs; these included cortical disruption, adjacent cutaneous ulcer, soft tissue mass, presence of a sinus tract, and adjacent soft tissue inflammation or oedema. The review also compared MRI with Tc 99m bone scanning, plain radiography and white blood cell studies in studies that directly compared the modalities.
Reference standard test against which the new test was compared
No specific inclusion criteria relating to the reference standard were specified. The reference standards used in the primary studies included biopsy; some studies did not specify a reference standard.
Participants included in the review
Studies of patients suspected of having osteomyelitis of the foot or ankle, or who had foot infection, were eligible for inclusion. At least 80% of the patients had to be aged 16 years or over to be included. In the included studies, the mean age ranged from 46 to 66 years and the prevalence of diabetes ranged from 70 to 100%. One study that included patients with suspected osteomyelitis in or around a Charcot joint was excluded.
Outcomes assessed in the review
Studies had to report sufficient data to construct a 2x2 table about discrete foot and ankle cases.
How were decisions on the relevance of primary studies made?
Two reviewers independently assessed studies for inclusion. A third reviewer resolved any disagreements.