Dell'Acqua Flavio, Rizzo Giovanna, Scifo Paola, Clarke Rafael Alonso, Scotti Giuseppe, Fazio Ferruccio
University of Milano-Bicocca, Milan, Italy.
IEEE Trans Biomed Eng. 2007 Mar;54(3):462-72. doi: 10.1109/TBME.2006.888830.
A deconvolution approach is presented to solve fiber crossing in diffusion magnetic resonance imaging. In order to provide a direct physical interpretation of the signal generation process, we started from the classical multicompartment model and rewrote this in terms of a convolution process, identifying a significant scalar parameter alpha to characterize the physical system response. Deconvolution is performed by a modified version of the Richardson-Lucy algorithm. Simulations show the ability of this method to correctly separate fiber crossing, even in the presence of noisy data, with lower signal-to-noise ratio, and imprecision in the impulse response function imposed during deconvolution. The in vivo data confirms the efficacy of this method to resolve fiber crossing in real complex brain structures. These results suggest the usefulness of our approach in fiber tracking or connectivity studies.
提出了一种去卷积方法来解决扩散磁共振成像中的纤维交叉问题。为了对信号生成过程提供直接的物理解释,我们从经典的多隔室模型出发,并将其改写为卷积过程的形式,确定了一个重要的标量参数α来表征物理系统响应。去卷积通过理查森 - 露西算法的改进版本进行。模拟结果表明,即使存在噪声数据、较低的信噪比以及去卷积过程中施加的脉冲响应函数不精确的情况,该方法仍能够正确分离纤维交叉。体内数据证实了该方法在解析真实复杂脑结构中纤维交叉方面的有效性。这些结果表明我们的方法在纤维追踪或连通性研究中的有用性。