METHODS: Twenty volunteers with osteoarthritis (OA) planning for total knee arthroplasty (TKA) were prospectively recruited. UTE-MRI sequences and conventional sequences were performed preoperatively. Regions of interests (ROIs) were manually drawn on the tibial plateau and lateral femoral condyle images to calculate MRI values. Cartilage samples were collected during TKA according to the preset positions corresponding to MR images. Pathological and biochemical components of the corresponding ROI, including histological grading, glycosaminoglycan (GAG) content, collagen integrity, and water content were obtained.
RESULTS: 91 ROIs from volunteers of 7 males (age range: 68 to 78 years; 74 ± 3 years) and 13 females (age range: 57 to 79 years; 67 ± 6 years) were evaluated. UTE-MTR (r = -0.619, p < 0.001), UTE-AdiabT1ρ (r = 0.568, p < 0.001), and UTE-T2* values (r = -0.495, p < 0.001) showed higher correlation with Mankin scores than T2 (r = 0.287, p = 0.006) and T1ρ (r = 0.435, p < 0.001) values. Of them, UTE-MTR had the highest diagnostic performance (AUC = 0.824, p < 0.001). UTE-MTR, UTE-AdiabT1ρ and UTE-T2* value was mainly related to collagen structural integrity, PG content and water content, respectively (r = 0.536, -0.652, -0.518, p < 0.001, respectively).
CONCLUSIONS: UTE-MRI have shown greater in vivo diagnostic value for early cartilage degeneration compared to conventional T2 and T1ρ values. Of them, UTE-MTR has the highest diagnostic efficiency. UTE-MTR, UTE-AdiabT1ρ, and UTE-T2* value mainly reflect different aspects of cartilage degeneration--integrity of collagen structure, PG content, and water content, respectively.
UNASSIGNED: Ultra-short echo time (UTE)-MRI has the potential to be a novel image biomarkers for detecting early cartilage degeneration in vivo and was correlated with biochemical changes of early cartilage degeneration.
CONCLUSIONS: Conventional MR may miss some early cartilage changes due to relatively long echo times. Ultra-short echo time (UTE)-MRI showed the ability in identifying early cartilage degeneration in vivo. UTE-MT, UTE-AdiabT1ρ, and UTE-T2* mapping mainly reflect different aspects of cartilage degeneration.
方法:前瞻性招募了20名骨关节炎(OA)计划行全膝关节置换术(TKA)的志愿者。术前进行UTE-MRI序列和常规序列。在胫骨平台和股骨外侧髁图像上手动绘制感兴趣区域(ROI)以计算MRI值。在TKA期间,根据与MR图像对应的预设位置采集软骨样本。相应ROI的病理和生化成分,包括组织学分级,糖胺聚糖(GAG)含量,胶原蛋白完整性,并获得含水量。
结果:评估了来自7名男性(年龄范围:68至78岁;74±3岁)和13名女性(年龄范围:57至79岁;67±6岁)志愿者的91个ROI。UTE-MTR(r=-0.619,p<0.001),UTE-AdabT1ρ(r=0.568,p<0.001),UTE-T2*值(r=-0.495,p<0.001)与Mankin评分的相关性高于T2(r=0.287,p=0.006)和T1ρ(r=0.435,p<0.001)。其中,UTE-MTR具有最高的诊断性能(AUC=0.824,p<0.001)。UTE-MTR,UTE-AdabT1ρ和UTE-T2*值主要与胶原结构完整性有关,PG含量和含水量,分别为(r=0.536,-0.652,-0.518,p<0.001)。
结论:与常规T2和T1ρ值相比,UTE-MRI对早期软骨退变的体内诊断价值更高。其中,UTE-MTR具有最高的诊断效率。UTE-MTR,UTE-AdabT1ρ,和UTE-T2*值主要反映软骨退化的不同方面——胶原结构的完整性,PG含量,和含水量,分别。
■超短回波时间(UTE)-MRI有可能成为检测体内早期软骨退变的新型图像生物标志物,并与早期软骨退变的生化变化相关。
结论:常规MR可能由于相对较长的回波时间而错过一些早期软骨改变。超短回波时间(UTE)-MRI显示了识别体内早期软骨退变的能力。UTE-MT,UTE-AdabT1ρ,UTE-T2*图谱主要反映软骨退变的不同方面。