Mark Brinckman
We chose to investigate the utility of marrow edema in the setting of acute fractures when we began to recognize some patients at our institution had known acute spine fractures on routine CT imaging, but when subsequently imaged by MRI, they lacked the presence of marrow edema. In an attempt to understand this phenomenon better, we developed a hypothesis that marrow edema is only reliably generated in the setting of vertebral body compression. Fractures that do not reliably generate marrow edema in the acute setting are those that arise from distracting or shear forces.
After a review of the available literature, we decided to test our hypothesis by conducting a 2-year retrospective review of those patients imaged at our institution with both modalities in the acute trauma setting. We carefully cataloged each patient’s fractures and the degree or absence of marrow edema. The results of this effort are presented here and appear to support the hypothesis that marrow edema remains a useful indicator of fracture acuity in the setting of vertebral body compression. In other types of fractures, for instance distraction type injuries, one should not be surprised by the lack of marrow edema on MRI in the acute trauma setting. In this setting, the clinician would be advised to rely on a broader clinical context and other findings such as soft tissue edema and/or ligamentous injury to suggest fracture acuity.
Fracture acuity in clinical practice is often not a diagnostic dilemma. However, in those cases where acuity has been called into question and MRI is obtained to provide additional characterization, the results of this investigation have informed our interpretation of the MRI data and guided our conclusions on fracture acuity in the setting of vertebral body compression versus fracture likely derived from distracting type forces.