Department of Radiology, Boston Children's Hospital, Boston, Massachusetts.
Harvard Medical School, Boston, Massachusetts.
Magn Reson Med. 2019 May;81(5):3314-3329. doi: 10.1002/mrm.27613. Epub 2018 Nov 16.
To achieve motion-robust diffusion compartment imaging (DCI) in near continuously moving subjects based on simultaneous multi-slice, diffusion-weighted brain MRI.
Simultaneous multi-slice (SMS) acquisition enables fast and dense sampling of k- and q-space. We propose to achieve motion-robust DCI via slice-level motion correction by exploiting the rigid coupling between simultaneously acquired slices. This coupling provides 3D coverage of the anatomy that substantially constraints the slice-to-volume alignment problem. This is incorporated into an explicit model of motion dynamics that handles continuous and large subject motion in robust DCI reconstruction.
We applied the proposed technique, called Motion Tracking based on Simultanous Multislice Registration (MT-SMR) to multi b-value SMS diffusion-weighted brain MRI of healthy volunteers and motion-corrupted scans of 20 pediatric subjects. Quantitative and qualitative evaluation based on fractional anisotropy in unidirectional fiber regions, and DCI in crossing-fiber regions show robust reconstruction in the presence of motion.
The proposed approach has the potential to extend routine use of SMS DCI in very challenging populations, such as young children, newborns, and non-cooperative patients.
基于同时多层、扩散加权脑 MRI,实现近连续运动受试者的运动稳健扩散容积成像(DCI)。
同时多层(SMS)采集能够快速、密集地采集 k 空间和 q 空间。我们建议通过利用同时采集的切片之间的刚性耦合,通过切片级别的运动校正来实现运动稳健的 DCI。这种耦合提供了对解剖结构的 3D 覆盖,大大限制了切片到体积配准问题。这被纳入到一个明确的运动动力学模型中,用于稳健的 DCI 重建中处理连续和大的受试者运动。
我们将这项名为基于同时多层配准的运动跟踪(MT-SMR)的技术应用于健康志愿者的多 b 值 SMS 扩散加权脑 MRI 和 20 名儿科受试者的运动污染扫描。基于单向纤维区域的各向异性分数和交叉纤维区域的 DCI 的定量和定性评估表明,在存在运动的情况下,该技术能够稳健地重建。
该方法有可能将 SMS DCI 在非常具有挑战性的人群中的常规使用扩展,例如儿童、新生儿和不合作的患者。