Marrow edema variability in acute spine fractures

Abstract

Background context: The presence or absence of marrow edema is used in the assessment of fracture acuity in magnetic resonance imaging (MRI). We have observed variability in the degree of marrow edema in acute trauma. Our aim was to characterize the utility of marrow edema in fracture detection and fracture acuity on MRI. We hypothesized that only vertebral body compression injuries reliably generate marrow edema and that distraction injuries or fractures without compression do not reliably generate marrow edema and may give a false negative MRI examination.

Purpose: To characterize the utility of marrow edema in fracture detection and fracture acuity on MRI.

Study design: Two-year single-center retrospective review of marrow edema in patients evaluated by both computed tomography (CT) and MRI in acute trauma setting.

Patient sample: The final study cohort consisted of 163 patients (mean age, 54.5 years; standard deviation, 23.5 years; range, 8-94 years; 85 men and 78 women).

Outcome measures: A physiologic measure of marrow edema as assessed by T2-signal hyperintensity on short tau inversion recovery sequence MRI examination.

Methods: After institutional review board approval, we conducted a retrospective review of 1,215 patients who were evaluated at our hospital for suspected spine trauma with a combination of CT and MRI. Patients were assessed for fracture presence, location, type, and absence or degree of marrow edema.

Results: The investigation identified 189/1,215 patients who had acute fractures on CT, subsequently imaged within 48 hours by MRI. A total of 94/288 acute fractures did not generate marrow edema. There were 63 patients (83 acute fractures) whose mechanism of injury resulted exclusively in acute fractures with no marrow edema. A statistically significant difference in marrow edema was observed with acute vertebral body compression fractures compared with acute fractures with distraction or fractures without compression. Moreover, certain fracture types were identified that often generate little or no marrow edema in acute trauma setting.

Conclusions: There is variability in the presence or degree of marrow edema on MRI evaluation after traumatic injury. Only fractures derived from vertebral body compression reliably generate marrow edema. Fractures without compression and/or fractures with distraction do not reliably generate marrow edema and can lead to a false negative MRI. An awareness of fracture types that produce more or less marrow edema can be beneficial when evaluating fractures by MRI.

Keywords: Acute spine fractures; Computed tomography; Distraction fractures; Magnetic resonance imaging; Marrow edema; Vertebral body compression fractures.