MRI quantification of diffusion and perfusion in bone marrow by intravoxel incoherent motion (IVIM) and non-negative least square (NNLS) analysis

作者：Marchand A J; Hitti E; Monge F; Saint Jalmes H; Guillin R; Duvauferrier R; Gambarota G^*

来源：Magnetic Resonance Imaging, 2014, 32(9): 1091-1096.

DOI：10.1016/j.mri.2014.07.009

• Intravoxel incoherent motion
• IVIM
• Diffusion
• Bone marrow
• Perfusion
• NNLS

Object: To assess the feasibility of measuring diffusion and perfusion fraction in vertebral bone marrow using the intravoxel incoherent motion (IVIM) approach and to compare two fitting methods, i.e., the non-negative least squares (NNLS) algorithm and the more commonly used Levenberg Marquardt (LM) non-linear least squares algorithm, for the analysis of IVIM data. %26lt;br%26gt;Materials and Methods: MRI experiments were performed on fifteen healthy volunteers, with a diffusion-weighted echo-planar imaging (EPI) sequence at five different b-values (0, 50, 100, 200, 600 s/mm(2)), in combination with an STIR module to suppress the lipid signal. Diffusion signal decays in the first lumbar vertebra (L1) were fitted to a hi-exponential function using the LM algorithm and further analyzed with the NNLS algorithm to calculate the values of the apparent diffusion coefficient (ADC), pseudo-diffusion coefficient (D*) and perfusion fraction. %26lt;br%26gt;Results: The NNLS analysis revealed two diffusion components only in seven out of fifteen volunteers, with ADC = 0.60 +/- 0.09 (10(-3) mm(2)/s), D* = 28 +/- 9 (10(-3) mm(2)/s) and perfusion fraction = 14% 6%. The values obtained by the LM hi-exponential fit were: ADC = 0.45 +/- 0.27 (10(-3) mm(2)/s), D* = 63 +/- 145 (10(-3) mm(2)/s) and perfusion fraction = 27% 17%. Furthermore, the LM algorithm yielded values of perfusion fraction in cases where the decay was not hi-exponential, as assessed by NNLS analysis. %26lt;br%26gt;Conclusion: The IVIM approach allows for measuring diffusion and perfusion fraction in vertebral bone marrow; its reliability can be improved by using the NNLS, which identifies the diffusion decays that display a hi-exponential behavior.

• 出版日期2014-11