T1ρ and T2 mapping reveal the in vivo extracellular matrix of articular cartilage

Purpose:

To determine the relationship between changes in the extracellular matrix (ECM) and T_1ρ and T₂ values in vivo. The ECM is composed of proteoglycan (PG), collagen, and water. It has been unclear which of the ECM constituents affects T_1ρ and T₂ mapping in living human cartilage.

Materials and Methods:

Sagittal T_1ρ and T₂ maps were preoperatively obtained from 20 knee osteoarthritis patients. Osteochondral samples harvested from the resected tibial plateaus during total knee arthroplasty were consistent with the MRIs of the patients' knees. Parameters that included histological grading of cartilage degeneration, glycosaminoglycan (GAG) content (which constitutes PG), presence of collagen anisotropy and water content were evaluated along with T_1ρ and T₂ values, and statistical analysis was performed using multiple regression analysis.

Results:

T_1ρ and T₂ values were significantly correlated with the degree of cartilage degeneration (β = 0.397 and 0.357, respectively) and the GAG content (β = ?0.340 and ?0.244, respectively).

Conclusion:

The present study demonstrated that T_1ρ and T₂ values reflect the GAG content of the cartilage and can indicate cartilage degeneration in vivo. Use of these parameters can facilitate the noninvasive diagnosis and evaluation of cartilage degeneration. J. Magn. Reson. Imaging 2012;35:147‐155. © 2011 Wiley Periodicals, Inc.

     

磁共振T1mapping在心脏疾病中的应用

心脏磁共振T1mapping技术能够直接定量心肌组织的T1值和细胞外间质容积分数(ECV),可以无创的评估许多不同的心脏疾病.尽管传统的钆剂延迟增强(LGE)技术能鉴别某些疾病状态下的局限性心肌纤维化,但对弥漫性心肌纤维化则并不可靠,而T1mapping技术则能够对LGE上不显示或显示不明显的心肌病变进行量化评估.本文简述了T1mapping技术在多种心脏疾病中的研究进展,在不同心肌病变(特别是弥漫性心肌纤维化)的定性评估和鉴别诊断上,利用T1mappping进行T1值和ECV定量检测可能是一种更加可靠和准确的方法.     

T1 mapping技术在肥厚型心肌病中的应用

目的:探讨T1 mapping技术在评价肥厚型心肌病(HCM)患者心肌整体纤维化中的应用价值,并分析HCM患者心肌纤维化程度与心脏功能的关系.方法:收集32例HCM患者为HCM组,招募17例正常者为对照组;2组均行心脏电影及T1 mapping序列检查,测量并比较2组左室心肌初始T1值、心脏功能的差异;通过构建ROC曲...     

心脏MR T1 mapping评估弥漫性心肌纤维化研究进展

T1 mapping技术可通过测量心肌组织的T1值直接反映心肌病变,能够在疾病早期诊断弥漫性心肌纤维化,并有助于显示常见心肌疾病的晚期弥漫性病变。介绍T1 mapping技术的基本原理及扫描序列,并就其在肥厚性心肌病、扩张型心肌病、先天性心脏病、心脏瓣膜病、心力衰竭和保留射血分数的心力衰竭等疾病中评估弥漫性心肌纤维化的应用进展进行综述。     

T1ρ and T2 mapping of the proximal tibiofibular joint in relation to aging and cartilage degeneration

Objective

To study the effects of aging and cartilage degeneration of the proximal tibiofibular- and femorotibial joint (PTFJ, FTJ) on the cartilage of the PTFJ using T₁ρ and T₂ mapping.

Materials and methods

We performed sagittal T₁ρ and T₂ mapping of the PTFJ and FTJ on 55 subjects with knee disorders. We placed 3 regions of interest (ROIs) on images of the cartilage in the PTFJ, medial femoral condyle (MFC), and medial tibia plateau (MTP). Correlation analysis was performed for the T₁ρ and T₂ values of each ROI and the patient age and the osteoarthritic grade of the PTFJ and FTJ.

Results

The T₁ρ and T₂ values of the PTFJ were affected neither by aging nor the osteoarthritic grade of the FTJ. Values of the FTJ normalized to PTFJ values were correlated with the osteoarthritic grade of the FTJ in the MFC (r = 0.851 and 0.779, respectively) and the MTP (r = 0.635 and 0.762, respectively). There was a significant difference in the T₁ρ but not the T₂ value of the PTFJ and MFC between normal and mildly osteoarthritic cartilage of each joint.

Conclusion

We document that the T₁ρ and T₂ values of PTFJ cartilage were not affected by aging or cartilage degeneration in the FTJ. The T₁ρ value of the PTFJ may represent a useful internal standard reference for evaluating early degeneration of the FTJ.     

心脏磁共振T1mapping技术评估肥厚型心肌病心肌纤维化

目的 基于心脏磁共振(CMR)T1 mapping技术定量评估肥厚型心肌病(HCM)心肌纤维化.资料与方法 回顾性收集2019年6月—2021年7月昆明医科大学第一附属医院45例HCM患者(HCM组)及44例CMR结果正常者(对照组)的临床及CMR资料,所有患者均行CMR检查,包括T1 mapping序列、延迟强化(L...     

Quantitative evaluation of knee cartilage and meniscus destruction in patients with rheumatoid arthritis using T1ρ and T2 mapping

ObjectiveTo calculate T1ρ and T2 values of articular cartilage and menisci in knee joints of patients with RA, and compare the values between RA patients and healthy volunteers, to gain insight into the pathogenesis of cartilage and meniscus degradation in patients with RA.Materials and methodsNine patients with RA and knee joints symptoms were enrolled in the study, twenty healthy volunteers without knee joint diseases were included as controls. Sagittal fat-saturated T1ρ and T2 mapping images were obtained on a 3T MR scanner (GE750, GE Healthcare, Waukesha, WI), using a dedicated 8-channel knee coil. In the T1rho mapping sequence, the amplitude of the spin-lock pulse was 500 Hz, spin lock durations = 10/20/30/50 ms. In the T2 mapping sequence,TR/TE were 1794/6.5, 13.4, 27, 40.7 ms. Both sequences were performed with the following parameters: flip angle (FA) = 90°, matrix: 320 × 256, FOV: 16 × 16 cm², slice thickness: 3 mm, bandwidth: 62.5 kHZ, and a total scan time of 5:11 min. T1ρ- and T2-mapping images were used for the segmentation of the articular cartilage of the patella, femoral trochlea, medial and lateral femoral condyle, medial and lateral tibial plateau. These images were also used for the segmentation of the anterior and posterior horns of the medial and lateral menisci with livewire semi-automatic segmentation algorithm of MATLAB. A Mann–Whitney U test was performed to compare the T1ρ and T2 values of the above mentioned regions between the two groups.ResultsT1ρ (Z = −3.913 to −2.121, P = 0.000–0.034) and T2 (Z = −3.866 to −2.216, P = 0.000–0.026) values of knee cartilage in patients with RA were higher than that in healthy volunteers, except the cartilage of the patella (T1ρ: Z = −1.273, P = 0.203,T2: Z = −0.236, P = 0.814) and lateral tibial plateau (T1ρ:Z = −1.037, P = 0.317). The T1ρ (Z = −1.462 to 0.572, P = 0.095–0.908) and T2 (Z = −1.461 to 0.278, P = 0.153–0.764) values of medial and lateral menisci showed no difference between the two groups.ConclusionPatients with RA exhibit diffuse knee cartilage destruction in the medial and lateral tibiofemoral joints and in the femoral trochlea. However, we found no increase in T1ρ and T2 values in menisci, this finding warrants further investigation.     

T1 mapping联合常规MRI扫描方案评估膝关节软骨损伤

目的评估在常规MRI扫描方案中加入T1 mapping成像能否提高对膝关节软骨损伤的诊断效能。方法选取86例患者的88个膝关节接受了膝关节MRI检查和关节镜检查。MRI检查采用常规方案并加入T1 mapping成像。术前2位影像科医师对所有MRI检查图像进行一致的诊断,评估是否存在软骨损伤并进行软骨损伤MRI分级,首先评估常规MRI扫描方案的图像,然后评估T1 mapping联合常规MRI扫描方案的图像。由1位骨科医师在关节镜下进行软骨损伤关节镜分级并作为金标准。计算两种MRI扫描方案评估软骨损伤的敏感度和特异度,统计分析两种扫描方案的诊断结果是否存在差异。结果关节镜检出的256个软骨损伤,常规MRI扫描方案的敏感度、特异度分别为59.0%和98.6%,T1 mapping联合常规MRI扫描方案的敏感度、特异度分别为85.9%和93.2%。T1 mapping联合常规MRI扫描方案显著提高了MRI扫描诊断早期关节软骨损伤的敏感度,关节镜1级软骨损伤的敏感度从18.6%提高至71.2%,关节镜2A级软骨损伤的敏感度从74.3%提高至94.3%。上述两种扫描方案的结果差异均有统计学意义(P<0.05)。结论常规MRI扫描方案中加入T1 mapping成像,可提高对膝关节软骨损伤的敏感度,为临床诊断早期膝关节软骨损伤提供影像学依据。     

Gd-EOB-DTPA增强MRI T1 mapping技术在肝脏疾病的应用进展

T_1 mapping成像是定量分析组织T_1值的方法,主要包括Look-Locker(LL)序列、改良的Look-Locker反转恢复序列(MOLLI)及可变多翻转角成像技术。近年来,基于Gd-EOB-DTPA的T_1 mapping成像广泛应用于肝脏。根据注射对比剂前后肝实质的T_1变化,不仅能用于对肝脏损伤程度、肝纤维化分期、肝硬化病人肝储备功能的评估,而且对肝脏局灶性病变的鉴别、肝细胞肝癌分化程度的预测也有一定的价值。就Gd-EOB-DTPA增强MRI T_1 mapping技术在肝脏疾病中的应用现状及研究进展予以综述。     

T2 mapping在周围神经疾病中的研究进展

MR T2 mapping可以通过测量组织T2值反映组织内水含量的变化,最早被应用于关节软骨和心肌病变的评估中。与传统的磁共振结构成像相比,它具有客观、精准、重复性高等优点。近年来,它在外周神经疾病中的应用越来越广泛。本文就T2 mapping的基本成像原理、在正常周围神经以及在不同种类周围神经疾病中的应用进展予以综述。     

Lumbar intervertebral disc abnormalities: comparison of quantitative T2 mapping with conventional MR at 3.0?T

Objective  

To assess the relationship of morphologically defined lumbar disc abnormalities with quantitative T2 mapping.     

Pre-surgical mapping of primary motor cortex by functional MRI at 3 T: effects of intravenous administration of Gd-DTPA

The functional magnetic resonance imaging (fMRI) is often performed at the end of a routine MRI examination during which, dependent on the clinical indication, contrast agent has been administered; however, the effects of Gd-DTPA injection on the results of blood oxygenation level dependent (BOLD)-fMRI remain unknown. The present study was conducted to investigate the effects of the intravenous administration of Gd-DTPA on the results of pre-surgical localization of the primary motor cortex by BOLD-fMRI at 3 T. Eight normal subjects were included in this study. After the anatomical scans, pre- and post-contrast fMRI scanning was performed. The number of significantly activated voxels and the mean percentage signal change were compared. The mean number of significantly activated voxels was 115.0±27.0 in pre-contrast runs and 90.8±27.1 in post-contrast runs (mean value of all 8 volunteers±standard deviation; p<0.05). The mean mean percentage signal change was 4.07±0.39 in pre-contrast runs and 3.86±1.91 in post-contrast runs (p=0.16). Pre-surgical localization of the motor area by BOLD-fMRI should be performed before the administration of Gd contrast material.     

T2 and T2∗ mapping in ex situ porcine myocardium: myocardial intravariability,temporal stability and the effects of complete coronary occlusion

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