Sugimoto H, Kimura T, Ohsawa T
Department of Radiology, Jichi Medical School, Japan.
Invest Radiol. 1993 Mar;28(3):208-13. doi: 10.1097/00004424-199303000-00003.
The authors assessed the capability of magnetic resonance imaging in measuring bone mineral density in vivo.
Using the in-phase asymmetric spin-echo technique, the susceptibility effect (T2*susceptibility) was measured in lumbar vertebrae in vivo. Calcium density was measured with single energy quantitative computed tomography scan. The values of the susceptibility effect were correlated with calcium density.
A statistically significant positive correlation was observed between signal loss due to susceptibility-induced inhomogeneity and the calcium density in the region of interest. The change in 1/T2susceptibility per unit change in density was 0.114 seconds-1/mg/cm3. T2susceptibility was 14.3 mseconds in volunteers and 17.4 mseconds in postoophorectomy patients.
To some extent, quantification of bone density is possible using magnetic resonance imaging; however, the relatively wide dispersion of the susceptibility effect, plotted against the calcium density in the axial skeleton, indicates that other factors, such as the three-dimensional structure of bone trabeculae, may play important roles in determining magnetic resonance parameters.
作者评估了磁共振成像在体内测量骨矿物质密度的能力。
采用同相不对称自旋回波技术，在体内测量腰椎的磁化率效应（T2*磁化率）。通过单能定量计算机断层扫描测量钙密度。将磁化率效应值与钙密度进行相关性分析。
在感兴趣区域，由磁化率诱导的不均匀性导致的信号损失与钙密度之间存在统计学上显著的正相关。密度每单位变化时1/T2磁化率的变化为0.114秒-1/毫克/立方厘米。志愿者的T2磁化率为14.3毫秒，卵巢切除术后患者为17.4毫秒。
在一定程度上，利用磁共振成像可以对骨密度进行量化；然而，相对于轴向骨骼中的钙密度，磁化率效应的相对广泛离散表明，其他因素，如骨小梁的三维结构，可能在决定磁共振参数方面发挥重要作用。
