3T MRI关节软骨成像序列的比较和探讨

目的:通过分析比较各3T MRI关节软骨成像序列对关节软骨显示的能力与限度,探讨理想的3T MRI关节软骨成像序列组合.方法:收集因临床需要而检查的36例膝关节MRI,成像设备为SIEMENS3.0T VERIO高场MRI,关节软骨成像序列包括:自旋回波序列(SE),二维脂肪抑制质子密度加权像(FS-PD),二维短T1翻转恢复序列(2D-STIR),三维双重回波稳态(3D-DESS),三维平衡稳态序列(3D-True FISP)和关节软骨生理成像T2mapping.在股骨髁间凹中央层面上分别测量股骨髁软骨信号噪声比(SNR)、软骨-关节液对比度噪声比(CNR),比较各序列对于软骨和周围关节液的显示能力.结果:3D-DESS,3D-True FISP和FS-PD序列软骨SNR最高(P<0.001);同时3D-DESS,3D-True FISP和FS-PD序列软骨-关节液对比度噪声比(CNR)高于2D-STIR,但软骨-关节液边界对比以3D-DESS序列最好,能显示关节软骨水含量变化的只有T2mapping成像.结论:二维脂肪抑制质子密度加权像(FS-PD)加上三维双重回波稳态(3D-DESS)是进行软骨MRI的理想序列组合,T2mapping可以显示关节软骨含水量的变化.     

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,...     

MR T1p成像技术在关节软骨中的研究进展

MR成像技术是对软骨损伤或退变进行检测的最重要的成像方法之一,具有较高的特异性、敏感性和精确性。能无创性地对软骨病变进行探测,直观地显示软骨的形态以及术后的状态。骨关节炎早期阶段的生化改变主要是关节软骨细胞外基质内蛋白多糖的丢失。而MR T1p技术是近年来发展的新技术,能间接反映软骨基质蛋白多糖含量变化,可对早期的软骨病变做出精确诊断。就MR T1p技术的基本原理、临床应用与研究进展予以综述。     

关节软骨MR成像进展

随着软骨序列的开发和应用，MRI对关节软骨的评价越来越重要。本文就关节软骨的MRI表现、关节软骨的MRI序列和扫描技术、关节软骨损伤以及修复术后MRI评价等方面进行了综述。     

正常骶髂关节软骨MRI成像分析

目的 探讨MRI显示正常骶髂关节软骨的最佳序列.方法 收集40例健康志愿者80侧骶髂关节软骨MRI扫描资料,其中男28例,女12例,年龄18~45岁,平均为29.36岁.均使用Philips Intera Achieva 1.5T 双梯度扫描仪,扫描序列包括轴位T1WI、T2WI、STIR、3D-WATS及斜冠状位T2WI.由2名资深医生对每侧骶髂关节软骨在不同序列显示情况进行分组评价,分为清晰、基本清晰、不清晰3组,统计处理各组间显示率差异.结果 40例健康志愿者80侧骶髂关节软骨在T1WI、T2WI、STIR、3D-WATS序列均可不同程度的显示,其中清晰组在各个序列的显示率为18.75%、0.00%、8.75%、93.75%,其中3D-WATS与T1WI、T2WI、STIR序列比较P＜0.05;T1WI、T2WI、STIR序列各组间比较P＞0.05.结论 3D-WATS序列是显示骶髂关节软骨的最佳序列.     

关节软骨MR成像技术研究进展

关节软骨损伤较常见,在临床应用磁共振成像（MRI）之前,由于缺乏较客观的依据,常延误诊断和治疗。近年来,关节软骨MR成像序列的设计和优化方面取得了明显进展。     

关节软骨MR研究进展

关节软骨属透明软骨,是关节的重要结构之一,易遭受创伤或出现退行性改变,损伤后不能自愈,且常继发出现骨结构或关节其他组织的改变。临床及传统影像学均不能无创性显示软骨结构。近十年来,MRI成为评价关节软骨病变的最重要无创性方法,且能对软骨治疗后效果和变化进行评估,包括软骨的形态学评价、体积定量评价、组织生化成分评价等。     

跑步运动相关的关节软骨MRI定量研究进展

近年来,随着全民健身的倡导,跑步越来越成为最受欢迎的体育运动之一,尤其是马拉松运动。同时人们对跑步运动损伤的关注度也越来越高,特别是膝关节及踝关节。关节软骨作为关节组成部分,一旦发生损伤,会导致关节退变及一系列的关节病变。MRI作为一项无创性检查,能够反映软骨在形态学改变出现前的早期生化成分改变,对早期诊断软骨病变有着重要价值。目前软骨的定量MRI技术主要包括T1ρ、T2 mapping、T2^*mapping等。笔者就跑步引起关节软骨改变的MRI定量研究进展进行综述。     

关节软骨MRI的进展

关节软骨在维持关节承重及正常活动中起重要作用。软骨病变是影响关节稳定的重要因素。MRI具有良好的信噪比及软组织分辨力,为诊断关节软骨病变提供了独特的检测方法,随着多种磁共振技术的开发应用,逐渐在关节病变中显示出其独特优势。     

关节软骨MRI的进展

关节软骨在维持关节承重及正常活动中起重要作用。软骨病变是影响关节稳定的重要因素。MRI具有良好的信噪比及软组织分辨力,为诊断关节软骨病变提供了独特的检测方法,随着多种磁共振技术的开发应用,逐渐在关节病变中显示出其独特优势。     

磁共振延迟增强软骨成像技术对正常及退变软骨的定量研究

目的：探讨磁共振延迟增强软骨成像对正常及退变软骨的定量研究价值。方法：69例正常及OA（退行性骨关节炎,osteoarthritis）患者经静脉注射Gd-DTPA对比剂1．5—2h后在3．0T磁共振下扫描,包括正常组（n=29）和0A组（n=40）。其中OA组按照kellgren-Lawrence评分又分为轻度OA组（n=20）、中度OA组（n=11）及重度OA组（n=9）。采用3DLL技术及后处理软件得到T,mapping图像,测量中层面内侧、中问及外侧T1值及上、中及下层面平均T1值,并进行统计学分析。结果：正常组、轻度OA组、中度OA组及重度OA组平均T1驰豫值分别为（512．59±72．30）ms、（458．03±55．89）in8、（405．89±57．30）ms及（357．92±36．74）ms。采用单因素方差分析,正常及OA组髌软骨Tl值有明显的差异（F=17．70,P=0．00〈0．05）。结论：磁共振延迟增强软骨成像技术可以敏感反映出关节软骨生化成分的改变,对关节软骨退变诊断具有一定指导价值。     

关节软骨病损的影像学诊断

目的 探讨慢性骨关节炎、类风湿性关节炎等几种慢性关节软骨损伤平片和MRI的诊断与鉴别诊断。方法 89例患者(骨关节炎61例，类风湿性关节炎9例，其他慢性损伤19例)共115个关节均行平片检查及MR T1WI、T2WI 质子密度加权像(PDWI)、短时反转恢复抑脂序列(STIR)、三维抑脂扰相梯度回波序列(3D FS SPGR)扫描，32例44个关节进行了增强扫描。其中90个膝关节的MRI分髌骨、股骨内髁、股骨外髁、胫骨4个关节面，按软骨病变Outerbridge分级法进行分析观察，61例75个关节进行了平片与MRI征象的对照观察。结果 MRI表现：关节软骨病变115个(100％)，同时伴有关节软骨变薄58个(50．4％)、软骨下骨质、骨髓改变22个(19．7％，)、滑膜增生52个(45．2％，)；类风湿性关节炎与骨关节炎组和其他慢性损伤组比较，类风湿性关节炎的软骨下骨质、骨髓改变的发生率与骨关节炎组及其他慢性损伤组差异有显著性意义(P值均=0．000)。把受累几率最大的髌软骨(81／90，90％)按MRI软骨病损Ⅰ～Ⅱ级为1组，Ⅲ～Ⅳ级为另1组，与平片的征象进行相关对照分析，两组间分别在平片的关节间隙狭窄(χ^2=9．349，P=0．002)、关节面下小囊变(χ^2=9．885，P=0．002)差异有非常显著性意义。结论Ⅰ～Ⅱ级软骨病变平片无恒定的征象，而Ⅲ～Ⅳ级软骨病变则可见关节间隙变窄与关节面下小囊变，主要与关节软骨病变及软骨下骨质改变相关：目前关节及关节软骨的影像学检查以X线平片结合MRI为最佳的检查方法，MR增强扫描有助于滑膜病变的诊断与鉴别诊断。     

T2 and T1rho MRI in articular cartilage systems.

T2 and T1rho have potential to nondestructively detect cartilage degeneration. However, reports in the literature regarding their diagnostic interpretation are conflicting. In this study, T2 and T1rho were measured at 8.5 T in several systems: 1) Molecular suspensions of collagen and GAG (pure concentration effects): T2 and T1rho demonstrated an exponential decrease with increasing [collagen] and [GAG], with [collagen] dominating. T2 varied from 90 to 35 ms and T1rho from 125 to 55 ms in the range of 15-20% [collagen], indicating that hydration may be a more important contributor to these parameters than previously appreciated. 2) Macromolecules in an unoriented matrix (young bovine cartilage): In collagen matrices (trypsinized cartilage) T2 and T1rho values were consistent with the expected [collagen], suggesting that the matrix per se does not dominate relaxation effects. Collagen/GAG matrices (native cartilage) had 13% lower T2 and 17% lower T1rho than collagen matrices, consistent with their higher macromolecular concentration. Complex matrix degradation (interleukin-1 treatment) showed lower T2 and unchanged T1rho relative to native tissue, consistent with competing effects of concentration and molecular-level changes. In addition, the heterogeneous GAG profile in these samples was not reflected in T2 or T1rho. 3) Macromolecules in an oriented matrix (mature human tissue): An oriented collagen matrix (GAG-depleted human cartilage) showed T2 and T(1rho) variation with depth consistent with 16-21% [collagen] and/or fibril orientation (magic angle effects) seen on polarized light microscopy, suggesting that both hydration and structure comprise important factors. In other human cartilage regions, T2 and T1rho abnormalities were observed unrelated to GAG or collagen orientation differences, demonstrating that hydration and/or molecular-level changes are important. Overall, these studies illustrate that T2 and T1rho are sensitive to biologically meaningful changes in cartilage. However, contrary to some previous reports, they are not specific to any one inherent tissue parameter.     

磁共振T2-mapping成像对早期膝关节软骨损伤的诊断价值研究

目的：测量不同程度膝关节骨关节炎（osteoarthritis,OA）患者和正常对照组关节软骨的T2弛豫时间并比较其差异性,评价磁共振T2-mapping成像在早期膝关节软骨损伤中的应用价值。方法：采用GE signa 3.0T磁共振扫描系统T2-mapping成像测量OA组（n=78）和正常组（n=32）膝关节股骨内侧髁、外侧髁,胫骨内侧髁、外侧髁4处软骨的T2值,并进行统计学分析。结果：正常组、轻度OA组、重度OA组平均T2值分别为（38.36±2.45）ms（、49.28±4.24）ms、（53.12±5.36）ms,病例组与对照组关节软骨表面T2值有差异且具显著性统计学意义（P〈0.05）,轻度OA组和重度OA组之间差别无统计学意义（P〉0.05）。结论：T2-mapping成像可以发现没有形态学改变的关节软骨内组织成分的变化,对早期膝关节软骨损伤的诊断和监测具有很高的临床应用价值。     

定量磁共振对膝关节软骨的应用研究进展

膝关节软骨在维持关节正常运动中起着缓冲、减震及润滑的关键作用。软骨定量磁共振成像是一种比较新的磁共振成像技术,能够对软骨内的细微组织成分进行量化评估,是评价膝关节软骨及其病变的一种有效的影像学检查方法。本文对膝关节软骨的正常组织结构和定量磁共振在膝关节软骨的量化评估及临床应用予以综述。     

Utility of delayed gadolinium-enhanced MRI (dGEMRIC) for qualitative evaluation of articular cartilage of patellofemoral joint

Delayed gadolinium-enhanced MRI of cartilage (dGEMRIC) was used for the measurement of relative proteoglycan depletion of articular cartilage in the patellofemoral (PF) joint following a proprietary protocol, which was compared with the X-ray images, proton density weighted MR images (PDWI) and arthroscopic findings. The study examined 30 knees. The ages ranged from 16 to 74 (average 40.3) years. The Gd-DTPA^2–containing contrast medium was used in a single dose. The subjects were made to exercise the knee joint for 10 min; and MR images were taken 2 h after intravenous injection of contrast medium. T1-calculated images were produced and the region of interest (ROI) was set as follows. (1) ROI1: entire articular cartilage in a slice through the center of the patella. (2) ROI2: low signal region in T1-calculated images, which were set in a blind fashion by two observers. (3) ROI3: articular cartilage on one side that includes ROI2 where low signal region were detected (medial or lateral). ROI3 was set to examine the contrast of ROI2 with surrounding articular cartilage. The average T1 values of ROI1 was 393.5±33.6 ms for radiographic grade 0 and 361.3±11.1 ms for grade I, which showed a significant difference (P=0.036). The T1 value of ROI2 was 351.6±28.2 ms for grade I, 361.9±38.3 ms for grade II, 362.1±67.7 ms for grade III, and 297.8±54.1 ms for grade IV according to arthroscopic Outerbridge classification. All cases, that demonstrated decrease of T1 values on dGEMRIC (ROI2), showed abnormal arthroscopic or direct viewing findings. The ratio (ROI3/ROI2) in cases of only slight damage classified as Outerbridge grade I (6 cases) was an average of 1.04±0.02 and was 1.0 or greater in all cases, thereby indicating well-defined contrast with the surrounding cartilage. The diagnosis of damage in articular cartilage was possible in all 16 cases with radiographic K–L grade I on dGEMRIC, while the intensity changes were not found in 10 of 16 cases on PDWI. The dGEMRIC with a single-dose would be useful on a diagnosis of the area demonstrating early relative proteoglycan depletion in the articular cartilage of the PF joint prior to any discernible changes in the subchondral bone on X-ray images and exceeds to plain MR images for examining deterioration of articular cartilage.