Objective

To develop and validate a 3D registration approach by which double echo steady state (DESS) MR images with cartilage thickness segmentations are used to extract the cartilage transverse relaxation time (T2) from multi-echo-spin-echo (MESE) MR images, without direct segmentations for MESE.

Materials and methods

Manual DESS segmentations of 89 healthy reference knees (healthy) and 60 knees with early radiographic osteoarthritis (early ROA) from the Osteoarthritis Initiative were registered to corresponding MESE images that had independent direct T2 segmentations. For validation purposes, (a) regression analysis of deep and superficial cartilage T2 was performed and (b) between-group differences between healthy vs. early ROA knees were compared for registered vs. direct MESE analysis.

Results

Moderate to high correlations were observed for the deep (r = 0.80) and the superficial T2 (r = 0.81), with statistically significant between-group differences (ROA vs. healthy) of + 1.4 ms (p = 0.002) vs. + 1.3 ms (p < 0.001) for registered vs. direct T2 segmentation in the deep, and + 1.3 ms (p = 0.002) vs. + 2.3 ms (p < 0.001) in the superficial layer.

Discussion

This registration approach enables extracting cartilage T2 from MESE scans using DESS (cartilage thickness) segmentations, avoiding the need for direct MESE T2 segmentations.

中文翻译：

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基于分段双回波稳态 (dess) 到多回波自旋回波 (mese) 图像的配准，对股胫软骨 t2 弛豫时间进行特定层分析。

客观的

开发和验证 3D 配准方法，通过该方法使用具有软骨厚度分割的双回波稳态 (DESS) MR 图像从多回波自旋回波 (MESE) MR 图像中提取软骨横向弛豫时间 (T2)，无需MESE 的直接分割。

材料和方法

来自 Osteoarthritis Initiative 的 89 个健康参考膝盖（健康）和 60 个患有早期放射学骨关节炎（早期 ROA）的手动 DESS 分割被注册到具有独立直接 T2 分割的相应 MESE 图像。出于验证目的，(a) 进行了深层和浅层软骨 T2 的回归分析，并且 (b) 比较了健康与早期 ROA 膝盖之间的组间差异，以进行注册与直接 MESE 分析。

结果

观察到深部 ( r  = 0.80) 和浅表 T2 ( r  = 0.81) 的中度至高度相关性，组间差异具有统计学意义（ROA 与健康），分别为 + 1.4 ms ( p  = 0.002) 与 + 1.3 ms ( p  < 0.001) 用于深层的配准与直接 T2 分割，+ 1.3 ms (p  = 0.002) 与 + 2.3 ms ( p  < 0.001) 在浅层。

讨论

这种配准方法可以使用 DESS（软骨厚度）分割从 MESE 扫描中提取软骨 T2，避免直接 MESE T2 分割的需要。