Purpose
1.Yeung et al described that fat degeneration of bone marrow related to osteoporosis,
i.e.,
low BMD,
was reflected by a decreasing apparent diffusion coefficient (ADC) [1].
In addition we earlier reported that the ADC was correlated with the BMD and fat fraction [2],
but the relation between the restricted diffusion of the water molecules and the trabecular bone structure was unclear.
On the other hand,
numerous studies indicated that the diffusion-weighted signal from a single voxel could be described as the sum of two exponential...
Methods and Materials
Materials:
On a 1.5-T MRI,
single-shot diffusionEPI was used with b values of 0 to 3000 s/mm2, and a sensitivity encoding technique.
We obtained the signal decay with b from selected regions of interest within a trabecular bone phantom,
which consisted of seven sponges changing the interspace areas,
and dry vertebral bone in a container filled with pure water (Fig.1).
Methods:
Signal decays with b obtained from selected regions of interest (ROI) within a trabecular bone phantom were fitted with the following equation:
SI =...
Results
A significant positive correlation was found between mean effective interspace diameter of the simulated trabecular bone and the fraction or ADC of the fast component (Fig.
1a and b).
On the other hand,
a significant negative correlation was found between the interspace diameter of the simulated trabecular bone and fraction of the slow component (Fig.
1c),
and a strong positive correlation was found between the interspace diameter and the ADC of the slow component (Fig.
1d).
These results show that restricted diffusion of the water...
Conclusion
Our original phantom enables to assess restricted diffusion, and the analytical method could obtain more detailed information on trabecular bone structure.
References
[1] Yeung DK,
et al,
J Magn Reson Imag,
19; 222-228,
2004.
[2] Ueda Y,
et al,
J Magn Reson Imag,
31; 632-635,
2010.
[3] Nienodorf T,
et al,
Magn Reson Med,
36; 847-857,
2001.