2288. Predictive Value of Imaging Characteristics on MRI and DWI on Patient Outcomes in Suspected Osteomyelitis of the Extremities
Authors * Denotes Presenting Author
  1. Mina Guirguis; University of Texas Southwestern Medical Center
  2. Parham Pezeshk; University of Texas Southwestern Medical Center
  3. Oganes Ashikyan; University of Texas Southwestern Medical Center
  4. Yin Xi; University of Texas Southwestern Medical Center
  5. Avneesh Chhabra *; University of Texas Southwestern Medical Center
To determine whether imaging characteristics on conventional MRI and diffusion-weighted imaging (DWI) are correlated to outcomes in patients with osteomyelitis.

Materials and Methods:
In this cross-sectional study, three musculoskeletal radiologists evaluated cases of potential osteomyelitis, soft tissue abscess, and intraosseous abscess. The readers reported imaging characteristics on conventional MRI sequences and DWI, along with minimum and mean apparent diffusion coefficient (ADC) measurements. Intraclass correlation (ICC) and Conger’s Kappa were used. These characteristics were then compared to the patient outcomes including amputation of the affected bone/limb, readmission for complications associated with the same bone, and death.

Among the 202 cases included, 132 patients were men and 70 were women, with 173 of the lower extremity and 29 of the upper extremity. Of these cases, 66 being negative for both OM and abscess, 30 with OM, 68 with soft tissue abscess, and 38 diagnosed with both soft tissue abscess and OM. The presence of hypointensity on T1W imaging and hyperintensity on T2W imaging, respectively, in the bone marrow were strong predictors of amputation (p value = <0.001). The presence of cortical destruction and periosteal edema likewise predicted amputation. However, no such trends were found with respect to readmission or death. DWI showed similar results – a significantly higher mean and minimum ADC value of the affected bone was associated with a higher likelihood of amputation. Conger’s Kappa for T1W and T2W intensity were 0.77 and 0.82, respectively, showing that these predictors are consistently identifiable among the readers.

Imaging characteristics on MRI and DWI are both highly predictive of the need for amputation in patients with osteomyelitis of the extremities. However, imaging does not seem to predict long-term impact of osteomyelitis, including risk of readmission and death.