Freiman M, Voss S D, Mulkern R V, Perez-Rossello J M, Warfield S K
Computational Radiology Laboratory, Childrens Hospital, Harvard Medical School, Boston, USA.
Med Image Comput Comput Assist Interv. 2011;14(Pt 2):74-81. doi: 10.1007/978-3-642-23629-7_10.
We present a new method for the uncertainty estimation of diffusion parameters for quantitative body DW-MRI assessment. Diffusion parameters uncertainty estimation from DW-MRI is necessary for clinical applications that use these parameters to assess pathology. However, uncertainty estimation using traditional techniques requires repeated acquisitions, which is undesirable in routine clinical use. Model-based bootstrap techniques, for example, assume an underlying linear model for residuals rescaling and cannot be utilized directly for body diffusion parameters uncertainty estimation due to the non-linearity of the body diffusion model. To offset this limitation, our method uses the Unscented transform to compute the residuals rescaling parameters from the non-linear body diffusion model, and then applies the wild-bootstrap method to infer the body diffusion parameters uncertainty. Validation through phantom and human subject experiments shows that our method identify the regions with higher uncertainty in body DWI-MRI model parameters correctly with realtive error of -36% in the uncertainty values.
我们提出了一种用于定量体部扩散加权磁共振成像(DW-MRI)评估中扩散参数不确定性估计的新方法。从DW-MRI进行扩散参数不确定性估计对于使用这些参数评估病理学的临床应用来说是必要的。然而,使用传统技术进行不确定性估计需要重复采集,这在常规临床应用中是不可取的。例如,基于模型的自助法技术假设了一个用于残差重缩放的基础线性模型,由于体部扩散模型的非线性,不能直接用于体部扩散参数的不确定性估计。为了弥补这一限制,我们的方法使用无迹变换从非线性体部扩散模型计算残差重缩放参数,然后应用野生自助法来推断体部扩散参数的不确定性。通过体模和人体实验验证表明,我们的方法能够正确识别体部DWI-MRI模型参数中具有较高不确定性的区域,不确定性值的相对误差为-36%。