Abstract:
Short association fibres (SAF) are the most abundant fibre pathways in the human white matter. Until recently, SAF could not be mapped comprehensively in vivo because diffusion weighted magnetic resonance imaging with sufficiently high spatial resolution needed to map these thin and short pathways was not possible. Recent developments in acquisition hardware and sequences allowed us to create a dedicated in vivo method for mapping the SAF based on sub-millimetre spatial resolution diffusion weighted tractography, which we validated in the human primary (V1) and secondary (V2) visual cortex against the expected SAF retinotopic order. Here, we extended our original study to assess the feasibility of the method to map SAF in higher cortical areas by including SAF up to V3. Our results reproduced the expected retinotopic order of SAF in the V2-V3 and V1-V3 stream, demonstrating greater robustness to the shorter V1-V2 and V2-V3 than the longer V1-V3 connections. The demonstrated ability of the method to map higher-order SAF connectivity patterns in vivo is an important step towards its application across the brain.
摘要:
短缔合纤维(SAF)是人类白质中最丰富的纤维途径。直到最近,SAF不能在体内被全面地映射,因为需要足够高的空间分辨率来映射这些薄且短的路径的扩散加权磁共振成像是不可能的。采集硬件和序列的最新发展使我们能够基于亚毫米空间分辨率扩散加权纤维束成像创建专用的体内方法来绘制SAF,我们在人类原发性(V1)和继发性(V2)视皮层中验证了预期的SAF视网膜位序。这里,我们扩展了我们的原始研究,以评估通过将SAF包含到V3来在较高皮质区域绘制SAF的方法的可行性.我们的结果再现了V2-V3和V1-V3流中SAF的预期视网膜位序,与较长的V1-V3连接相比,较短的V1-V2和V2-V3具有更大的鲁棒性。该方法在体内绘制高阶SAF连接模式的能力是其在大脑中应用的重要一步。