Josef Lissner Laboratory for Biomedical Imaging, Department of Clinical Radiology - Grosshadern, LMU Ludwig Maximilian University of Munich, Munich, Germany.
Eur J Radiol. 2010 Dec;76(3):298-303. doi: 10.1016/j.ejrad.2010.05.020. Epub 2010 Jun 30.
To evaluate the potential and to analyze parameter correlations of combined quantitative diffusion-weighted MRI (DWI) and high-temporal-resolution dynamic contrast-enhanced MRI (DCE-MRI) in vertebral bone marrow (vBM) of patients with osteoporosis and acute vertebral compression fractures, providing additional information for a better understanding of the physiological background of parameter changes.
20 patients with acute osteoporotic fractures were examined with DWI and DCE-MRI at 1.5 T. DCE-MRI was performed with a 2D saturation-recovery turbo-FLASH sequence, acquiring 300 dynamics with a temporal resolution of 1 s. For DWI measurements, a DW HASTE sequence with b-values from 100 to 600 s/mm² was applied. In each patient, ROIs were drawn manually in the fractures and in normal appearing vertebrae. For DCE-MRI, the concentration-time curves of these ROIs were analyzed using a two-compartment tracer-kinetic model in the lesions, providing separate estimates of perfusion and permeability, and a one-compartment model in normal vBM, providing only a mixed representation of perfusion and permeability in terms of a mixed flow parameter K(trans) and the extracellular volume (ECV). In the case of DWI, attenuation curves were fitted to a monoexponential decay model to determine the apparent diffusion coefficient (ADC).
Mean perfusion parameters and ADCs were significantly (p<0.001) different in the fractures compared to adjacent normal appearing vertebrae (K(trans): 7.81 mL/100 mL/min vs. 14.61 mL/100 mL/min, ECV: 52.84 mL/100 mL vs. 4.61 mL/100 mL, ADC: 1.71×10⁻³ mm²/s vs. 0.57×10⁻³ mm²/s). ADCs showed a significant correlation with the ECV.
The quantitative analysis of DWI and DCE-MRI could distinguish osteoporotic fractures from normal appearing vertebrae. A significant correlation found between ECV and ADCs might be able to explain the cause for the increased diffusivity in osteoporotic fractures. Since the other perfusion parameters do not correlate with the ADC, they provide additional pathophysiological information not accessible with DWI.
评估定量弥散加权 MRI（DWI）和高时间分辨率动态对比增强 MRI（DCE-MRI）在骨质疏松症和急性椎体压缩性骨折患者椎骨骨髓（vBM）中的潜力，并分析其参数相关性，为更好地了解参数变化的生理背景提供额外信息。
在 1.5 T 磁共振扫描仪上对 20 例急性骨质疏松性骨折患者进行 DWI 和 DCE-MRI 检查。DCE-MRI 采用二维饱和恢复涡轮 FLASH 序列进行，时间分辨率为 1 s，采集 300 个动态图像。DWI 测量采用 DW HASTE 序列，b 值范围为 100 至 600 s/mm²。在每个患者中，手动在骨折部位和正常椎体部位绘制 ROI。对于 DCE-MRI，使用双室示踪剂动力学模型分析这些 ROI 的浓度-时间曲线，在病变部位分别估计灌注和渗透性，并在正常 vBM 中使用单室模型，根据混合流参数 K(trans)和细胞外容积（ECV）提供灌注和渗透性的混合表示。在 DWI 的情况下，衰减曲线拟合单指数衰减模型以确定表观扩散系数（ADC）。
与相邻正常椎体相比，骨折部位的平均灌注参数和 ADC 值存在显著差异（p<0.001）（K(trans)：7.81 mL/100 mL/min 比 14.61 mL/100 mL/min，ECV：52.84 mL/100 mL 比 4.61 mL/100 mL，ADC：1.71×10⁻³ mm²/s 比 0.57×10⁻³ mm²/s）。ADC 值与 ECV 呈显著相关性。
DWI 和 DCE-MRI 的定量分析能够区分骨质疏松性骨折和正常椎体。发现 ECV 与 ADC 值之间存在显著相关性，这可能能够解释骨质疏松性骨折中扩散增加的原因。由于其他灌注参数与 ADC 不相关，因此它们提供了 DWI 无法获得的额外病理生理信息。
