Bone marrow perfusion magnetic resonance imaging in patients with osteoporotic vertebral compression fractures: peak enhancement ratio is an independent predictor for intraosseous vacuum phenomena

Introduction Osteoporotic vertebral compression fractures (VCF) are common in routine medical practice and usually heal without neurologic complications. However, vertebral bodies that are severely osteoporotic and located in thoracolumbar junction are more susceptible to non-healing with resultant intravertebral cleft formation (1). Recently, dynamic contrast enhanced magnetic resonance imaging (DCE -MRI) has been used for the evaluation of bone marrow perfusion (2, 3).In this study, we prospectively investigate the relationship between intraosseous clefts and bone marrow perfusion using dynamic contrast-enhanced magnetic resonance images (DCE-MRI) in patients with osteoporotic vertebral compression fractures. Material s and Methods Forty subjects referred for evaluation of vertebral compression fracture underwent DCE-MRI from T8 to sacrum. Bone marrow perfusion, as measured using the DCE-MRI time-intensity curve from a non-injured vertebrae was developed using 2 distinct parameters including peak enhancement ratio (PER) (which indicates tissue perfusion) and enhancement slope (which reflects vascularity). The ratio of the well-enhanced to the poorly-enhanced zone of each injured vertebra was calculated. Multiple logistic regression analysis was used to evaluate the relationships between baseline clinical factors, parameters of DCE-MRI and presence or absence of intraosseous clefts. Results and Discussions Twenty-nine injured vertebrae (72%) had intraosseous clefts. The cleft group showed significantly lower PER (p = 0.001) (Fig. 1 and Fig. 2) and a less well-enhanced zone ratio (p = 0.049) than the ‘no cleft’ group. Lower PER of the non-injured vertebrae was associated with higher poorly-enhanced zone ratio of the injured vertebrae (γ = -0.362, p = 0.017). Multivariate logistic regression analysis identified lower PER (hazard ratio, 0.000; 95% confidence interval, 0.000-0.096; p = 0.009) as an independent predictor of intraosseous clefts. A PER value less than 0.57 had a sensitivity of 80% and specificity of 90% for predicting intraosseous clefts (Fig. 3).