Lumbar intervertebral disc characterization through quantitative MRI analysis: An automatic voxel-based relaxometry approach
Lumbar intervertebral disc characterization through quantitative MRI analysis: An automatic voxel-based relaxometry approach
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DOI：
10.1002/mrm.28210
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发表时间：
2020-02-14
影响因子：
3.3
通讯作者：
Majumdar, Sharmila
中科院分区：
文献类型：
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作者：
Iriondo, Claudia;Pedoia, Valentina;Majumdar, Sharmila
目的开发一种基于卷积神经网络的自动化流水线，使用基于体素的松弛测量法分割腰椎间盘并表征其生化成分，并建立与残疾，肌肉变化和其他下背痛症状的临床测量的局部关联。方法这项工作提出了一种新的方法，使用MRI（n = 31，在椎间盘退变的范围内），结合了基于深度学习的分割，基于图谱的配准，和统计参数映射，用于T-1 rho和T-1 rho的基于体素的分析。2弛豫时间图表征椎间盘退变及其相关disability.Results跨退行性分级，分割算法产生准确的，高置信度分割的腰椎间盘在两个独立的数据集。手动和自动提取的平均椎间盘T-1 rho和T-2弛豫时间在所有椎间盘中高度一致，偏差最小。在逐体素基础上，基于成像的退行性分级与T-1 rho和T-2呈强烈负相关，特别是在核中。按残疾等级对患者进行分层，发现轻度/中度与重度残疾之间的松弛图存在显著差异：轻微/中度残疾组的平均T-1 rho松弛图显示了清晰的环核区分，中线可见，而重度残疾组的平均T-1 rho值较低，分布均匀。椎间盘松弛时间的自动评估，以及基于体素的松弛测量，其克服了当前基于感兴趣区域的分析方法的局限性，并且可以实现椎间盘退变、残疾和下背痛之间的更深入的了解和关联。
Purpose To develop an automated pipeline based on convolutional neural networks to segment lumbar intervertebral discs and characterize their biochemical composition using voxel-based relaxometry, and establish local associations with clinical measures of disability, muscle changes, and other symptoms of lower back pain.Methods This work proposes a new methodology using MRI (n = 31, across the spectrum of disc degeneration) that combines deep learning-based segmentation, atlas-based registration, and statistical parametric mapping for voxel-based analysis of T-1 rho and T-2 relaxation time maps to characterize disc degeneration and its associated disability.Results Across degenerative grades, the segmentation algorithm produced accurate, high-confidence segmentations of the lumbar discs in two independent data sets. Manually and automatically extracted mean disc T-1 rho and T-2 relaxation times were in high agreement for all discs with minimal bias. On a voxel-by-voxel basis, imaging-based degenerative grades were strongly negatively correlated with T-1 rho and T-2, particularly in the nucleus. Stratifying patients by disability grades revealed significant differences in the relaxation maps between minimal/moderate versus severe disability: The average T-1 rho relaxation maps from the minimal/moderate disability group showed clear annulus nucleus distinction with a visible midline, whereas the severe disability group had lower average T-1 rho values with a homogeneous distribution.Conclusion This work presented a scalable pipeline for fast, automated assessment of disc relaxation times, and voxel-based relaxometry that overcomes limitations of current region of interest-based analysis methods and may enable greater insights and associations between disc degeneration, disability, and lower back pain.