Performance of a rapid two-sequence screening protocol for osteomyelitis of the foot
Compare a two sequence protocol to a standard protocol in the detection of pedal osteomyelitis (OM) and abscesses and to identify patients that benefit from a full protocol.
Materials and methods
One hundred thirty-two foot MRIs ordered to assess for OM were enrolled, and the following items were extracted from the clinical reports: use of IV contrast, the presence of OM, reactive osteitis, and a soft tissue abscess. Using only one T1 nonfat-suppressed and one fluid sensitive fat-suppressed sequences, two experienced musculoskeletal radiologists reviewed each case for the presence of OM, reactive osteitis, or an abscess. A Kappa test was calculated to assess for interobserver agreement, and diagnostic performance was determined. The McNemar test was used to assess for the effect of contrast.
Agreement between both observers and the clinical report on the presence of osteomyelitis was substantial ( k = 0.63 and 0.72, p < 0.001), while the agreement for abscess was fair (k = 0.29 and 0.38, p < 0.001). For osteomyelitis, both observers showed good accuracy (0.85 and 0.86). When screening bone for a normal versus abnormal case, this method was highly sensitive (0.97–0.98), but was less sensitive for abscess (0.63–0.75). Fifty-one percent of exams used contrast, and it did impact the diagnosis of abscess for one observer.
This rapid protocol is accurate in making the diagnosis of OM, and its high sensitivity makes it useful to screen for patients that would benefit from a full protocol.
KeywordsMRI Screening Osteomyelitis Pedal Foot
Diabetic foot ulcer
American College of Radiology
Below the knee amputation
Short tau inversion recovery
Drs. Umpierrez and Kakarala did the review of the 132 cases. Drs. Maceroli and Rajani provided the surgical insight for the project from an orthopedic and vascualar surgery perspective, respectively. Dr. Schechter provided insight from an infectious disease perspective. Dr. Sharma helped with statistics. All authors were involved in drafting and editing the manuscript.
Compliance with ethical standards
Conflict of interest
The authors declare that they have no conflict of interest.
- 15.Kotecha HM, Lo HS, Vedantham S, Shin H, Cerniglia CA. Abbreviated MRI of the foot in patients with suspected osteomyelitis. Emerg Radiol. 2019.Google Scholar