Imamura Rui, Teramoto Atsushi, Murahashi Yasutaka, Okada Yohei, Okimura Shinichiro, Akatsuka Yoshihiro, Watanabe Kota, Yamashita Toshihiko
Department of Orthopaedic Surgery, School of Medicine, Sapporo Medical University, Sapporo, Japan.
Second Division of Physical Therapy, School of Health Sciences, Sapporo Medical University, Sapporo, Japan.
Cartilage. 2025 Mar;16(1):118-124. doi: 10.1177/19476035231205685. Epub 2023 Oct 16.
Ultra-short TE (UTE) sequences on MRI are a technique that improves the visualization of tissues with short T2 relaxation time, such as deep cartilage layers. In addition, T2* relaxation time calculated from the UTE has the potential to evaluate water molecules bound to the cartilage matrix. This study was performed to determine if there is an association between UTE-T2* relaxation time by cartilage layer and histological degeneration in knee osteoarthritis (OA).
Seven knees that had undergone total knee arthroplasty (TKA) were included in the study, and the lateral tibial cartilage, which had the least degeneration of the resected bones, was used as the sample. The T2* relaxation time of 4 patients with no abnormal findings on MRI was the reference relaxation time. Histological degeneration of TKA samples was assessed by the Mankin score and graded as the early OA group (≤3 points) and the advanced OA group (≥4 points). The association between T2* relaxation time and Mankin grade in each cartilage layer was compared. The effect of angiogenesis to the tidemark on T2* relaxation time was also compared.
T2* relaxation time of the cartilage layer was significantly longer in early OA than that in the control group. In the deep cartilage layer, the mean T2* relaxation time for angiogenesis (-) was 15.7 ms, whereas it was significantly shorter for angiogenesis (+) at 8.2 ms.
The UTE-T2* relaxation time was associated with histological cartilage degeneration, suggesting a potential application in monitoring early cartilage degeneration.
MRI上的超短TE（UTE）序列是一种可改善对具有短T2弛豫时间的组织（如深层软骨层）可视化的技术。此外，由UTE计算得出的T2弛豫时间有潜力评估与软骨基质结合的水分子。本研究旨在确定膝关节骨关节炎（OA）中软骨层的UTE-T2弛豫时间与组织学退变之间是否存在关联。
本研究纳入了7例接受全膝关节置换术（TKA）的膝关节，将切除骨中退变程度最轻的外侧胫骨软骨用作样本。4例MRI无异常发现患者的T2弛豫时间作为参考弛豫时间。通过Mankin评分评估TKA样本的组织学退变，并分为早期OA组（≤3分）和晚期OA组（≥4分）。比较各软骨层中T2弛豫时间与Mankin分级之间的关联。还比较了潮标处血管生成对T2*弛豫时间的影响。
早期OA组软骨层的T2弛豫时间显著长于对照组。在深层软骨层，血管生成（-）时的平均T2弛豫时间为15.7毫秒，而血管生成（+）时则显著缩短，为8.2毫秒。
UTE-T2*弛豫时间与软骨组织学退变相关，提示其在监测早期软骨退变方面具有潜在应用价值。
