基于MRI的成人正常膝关节软骨形态学测量

目的：了解正常膝关节软骨分布及股骨髁承重区的软骨厚度特点,为膝关节病变早期诊断和动态观察提供依据。方法：选取100名成人志愿者,男、女各50名,年龄20—30岁,平均25．3岁,膝关节均行MRI扫描。应用MIMICS软件对图像进行处理,在矢状位窗面上测量膝关节各部位软骨最大厚度。选择膝关节正常运动时的承重区,测量承重区域软骨的最大厚度并与其他区域进行比较。基于MRI图像行膝关节软骨三维重建,观察膝关节软骨的三维形态特征。结果：膝关节各部位的最大软骨厚度如下。胫骨外侧平台3．19mm,胫骨内侧平台3．07mm,股骨外侧髁2．93mm,股骨内侧髁3．19mm,股骨滑车软骨3．57mm,髌软骨3．75mm。不同性别与左右侧之间的软骨厚度差异无统计学意义（P〉0．05）。胫股关节承重区软骨厚度大于其他区域,有统计学差异（P〈0．05）。结论：成人正常膝关节各区域软骨厚度不同,胫股关节承重区软骨厚度大于非承重区域。基于MRI可以准确地测量膝关节各部软骨的厚度及重建膝关节软骨的三维形态。     

正常膝关节软骨MRI T_1ρ序列表现初步研究

目的比较正常膝关节软骨MRIT1ρ和三维抑脂扰相梯度回波(3D-FS-SPGR)序列表现,研究T1ρ序列应用于软骨评估的可行性;评估软骨深层与浅层MRIT1ρ值的差异。方法选择经临床和影像确认的26例成年志愿者,其中男性11例,女性15例;年龄15~65岁,平均年龄31.69岁。分析其T1ρ和3D-FS-SPGR序列MRI成像表现。将膝关节软骨划分为髌软骨、髁间窝、股骨内外侧髁、胫骨内外侧平台6个部分。测量相同层面与位置的T1ρ第一回波和3D-FS-SPGR图像上软骨、软骨下骨、背景噪声的信号强度,比较两者的软骨与软骨下骨对比度比(CNR)和软骨信噪比(SNR)。选取6个部位软骨最厚处,把该处软骨厚度等分为深层和浅层,分别测量同像素感兴趣区(ROI)的T1ρ值。对以上数据进行配对t检验,以P0.05为差异有统计学意义。结果①膝关节T1ρ序列第一回波图像上的CNR均值和SNR均值均高于同一部位的3D-FSSPGR序列,CNR 29.88±10.00 vs 12.08±3.08(t=23.09,P=0.000),SNR 34.70±11.16 vs 14.18±3.46(t=23.929,P=0.000);②正常膝关节软骨深层均值(29.12±8.07)ms,浅层均值(43.23±6.78)ms,浅层T1ρ值显著高于深层表现(t=-24.687,P=0.000)。结论 T1ρ序列可用于软骨临床评估,浅层软骨胶原纤维排列较深层更为致密。     

膝关节关节软骨的三维构建

目的:构建膝关节关节软骨的三维模型,为开展膝关节数字医学研究进行模型构建的探索。方法:人体成年新鲜膝关节标本1例,行CT、MRI扫描,利用三维重建软件Mimics及逆向工程软件Geomagic对图像进行三维重建及图像配准,构建膝关节骨、关节软骨结构。结果:利用Mimics 10.01软件构建关节软骨的三维模型,并形成骨-关节软骨复合模型,导入Geomagic软件中与CT构建的骨三维模型相配准,再次导入CT影像中进行逐层微修饰,验证关节软骨分割效果。最终建立具有骨、关节软骨的三维膝关节模型。结论:三维图像重建技术与图像配准技术可将CT、MRI图像两者结合起来,发挥其各自优势,构建出形态较好的膝关节三维模型。     

正常成人松果体MRI研究

目的　建立正常成人松果体MRI测量标准,并分析其性别差异及年龄变化规律。 方法　MRI扫描327例正常成人头颅,测量并分析松果体相关数据。 结果 松果体矢径女性（7.12±1.11） mm,男性（6.52±1.01）mm（女性>男性,P<0.05）;松果体横径女性（5.72±0.98）mm,男性（5.38±1.07）mm;松果体高女性（4.38±0.43）mm,男性（4.03±0.62）mm;松果体体积女性（88.92±27.90）mm3,男性（74.35±23.62）mm3（女性>男性,P<0.05）。 结论 松果体矢径和体积女性大于男性,松果体体积性别差异出现在31~60岁。     

国人正常膝关节几何学参数测量及临床意义

目的：从几何学角度对国人正常膝关节的参数进行测量,探讨其与某些膝关节疾病的关系.方法：选取国人无明显损坏的干燥股骨标本和胫骨标本各83例,测量股骨长度（G）,股骨内、外侧髁宽度（G1、G2）,股骨髁间窝宽度（G3）及深度（G4）,股骨内、外侧髁倾斜角（GD1、GD2）,胫骨近端平台内、外侧后倾角（JD1、JD2）,胫骨近端内、外侧平台的前后经（J1、J3）、左右径（J2、J4）,胫骨近端平台髁间隆起的宽度（J5）及高度（J6）.测量后对有关参数进行统计学分析.结果：除J2对J4外,其余膝关节几何参数测量值之间配对检验其差异存在统计学意义（P＜0.05）.线性参数之间呈正相关关系（P＜0.05）,而线性参数与角度参数之间无相关关系（P＞0.05）.结论：根据所测得的结果,建立了国人正常膝关节几何参数的数据库,为某些膝关节疾病的病程分型与治疗提供参考.     

汉族成人膝关节软骨厚度变化规律的研究

目的借助软骨磁共振成像技术研究我国20～40岁成年人膝关节软骨厚度变化规律及其与年龄、体质量和性别等与骨关节炎有关的主要临床因素的相关性。方法对200例20～40岁间汉族正常志愿者进行磁共振(MR)膝关节软骨成像,序列包括:快速自旋回波加权(FSE T2W)、三维脂肪抑制扰相梯度回波(3D-FS-SPGR)和脂肪抑制质子加权(FS-PD)。分别记录股骨内侧髁、外侧髁、胫骨内侧平台、外侧平台和髌骨区5个区域软骨最大厚度。同时分别记录关节胫股角、身高、体质量并计算体质指数(BMI)。分析不同性别、BMI正常和超质量组、不同年龄段(以5岁年龄差为一年龄组)的膝关节各区域之间软骨厚度差异;采用多元方差分析不同年龄组软骨厚度总体差异;采用Sperman分析法对年龄、BMI、性别与软骨厚度的相关性进行分析。结果样本胫股角平均值为4.6°,不同组间差异无统计学意义(F=14.683,P=0.094);不同年龄组在股骨内侧髁和胫骨内、外侧平台软骨厚度方面存在显著性差异,以上区域软骨随年龄增大而变薄的趋势明显(F=2 968.790,P<0.001);软骨厚度与年龄具有较为明显的负相关性(r外侧平台=-0.352,r内侧平台=-0.475,r股骨内侧髁=-0.363)。不同性别间软骨平均厚度差异无统计学意义(t=0.4235,P=0.672)。超质量与体质量正常组间软骨平均厚度无显著差异(t=0.798,P=0.425);成年人股骨外侧髁软骨厚度与BMI负相关(r=-0.162,P=0.022),其余部位与BMI无相关性。结论在我国20～40岁正常成年人中,膝关节不同区域的软骨厚度差异显著且随年龄变化明显。该年龄段正常人膝关节软骨厚度与性别、体质量无相关性。     

软骨修复材料在运动性膝关节软骨损伤修复中的作用

背景：评价软骨修复材料在膝关节软骨损伤修复中的效果,为医务、科研工作者的研究提供一定的借鉴。 方法：采用电子检索的方式,在万方数据库(http://www.wanfangdata.com.cn/)中检索2000-01/2011-03关于修复材料在膝关节软骨损伤研究的文章,关键词为“生物材料;关节软骨;缺损;修复”。排除重复研究、普通综述或Meta分析类文章,筛选纳入26篇文献进行评价。 结果：膝关节软骨损伤在运动性损伤中较为常见,现在主要的治疗方法是自体骨软骨移植修复膝关节软骨缺损。新型的软骨替代材料研究仍处于动物试验阶段,且在动物体内长期疗效及远期的生物力学变化还未有进一步的证实,进入临床试验更需要一个过程。 结论：关节软骨损伤修复的基础研究与临床治疗,虽仍存在许多重点和难点问题亟待探索,但关节软骨损伤修复正从生物材料移植向人工再造活性软骨的崭新阶段迈进。随着各种新型材料的研制和开发,关节软骨损伤修复研究将日益完善,并为临床奠定坚实的基础,应用前景十分广阔。     

超声评价膝关节软骨退行性变与手术的对照研究

目的 探讨膝关节软骨不同时期退行性变(退变)的超声表现,并进一步分析超声的诊断价值.方法　对行关节镜手术的9个膝关节用超声术中经皮实时观察,对关节置换术的2个膝关节标本(置生理盐水中)进行离体观察.总结正常软骨及Ⅰ～Ⅳ期软骨退变的超声表现.以此为超声诊断标准,术前检查40例患者的41个膝关节,将超声诊断与关节镜结果及手术切除标本对照.结果 正常软骨表现为高-低-高"夹心饼断面"样回声带,Ⅰ期退变常无异常,Ⅱ期退变软骨表面毛糙,轻度变薄或局部隆起,Ⅲ期退变软骨局部变薄,Ⅳ期退变软骨层完全丧失.超声诊断膝关节软骨退变的敏感性、特异性、准确性分别为64.9%、92.0%、76.5%.结论 除Ⅰ期外,其余各期关节软骨退变在超声上均有一定特点.超声可作为诊断膝关节软骨退变的重要辅助手段.     

新疆维吾尔族人群正常膝关节参数的CT测量及其临床意义

目的 探讨应用CT测量新疆维吾尔族人正常膝关节参数在膝关节假体设计中的临床价值。方法 根据纳入标准招募新疆维吾尔族成年志愿者100名进行前瞻性研究,男53名,女47名;年龄18~68岁,平均34.07岁。行膝关节伸直中立位CT扫描,扫描图像用AW4.4进行3D重建处理,抛币法选取左侧或右侧膝关节,分别测量记录髌骨厚度、胫骨平台内翻角(PT角)、小腿机械轴垂直线与双侧股骨髁远端切线的夹角(FT角),以及胫骨内侧平台最低点至腓骨头尖端高度的差距(DPF)等膝关节参数。将所得数据分别按男女组进行统计学处理,并将所得数值同文献报道的汉族人相关数据进行统计学比较。结果 新疆维吾尔族人正常膝关节髌骨厚度、PT角、FT角、DPF男性分别为(22.67±1.40)mm、4.64°±0.61°、4.85°±0.84°、(9.75±1.70)mm,女性分别为(20.70±1.41)mm、4.23°±0.55°、4.33°±0.58°、(8.13±1.80)mm,男性与女性之间的差异均有统计学意义(t值分别是7.006、3.512、3.543、4.634,P值均<0.01)。与相关文献报道的汉族人群相比,维吾尔族正常膝关节髌骨厚度、PT角、FT角之间的差异均无统计学意义(t值分别是1.056、0.844、0.572,P值均>0.05),DPF之间的差异有统计学意义(t=3.996,P<0.01)。结论 对新疆维吾尔族人进行全膝关节置换术,包括髌骨置换术等操作时,为确保操作精确性,不能直接参考其他人群相关数据;设计国人膝关节假体时应该考虑到不同人群及性别的差异。     

Automatic Articular Cartilage Segmentation Based on Pattern Recognition from Knee MRI Images

An automatic method for cartilage segmentation using knee MRI images is described. Three binary classifiers with integral and partial pixel features are built using the Bayesian theorem to segment the femoral cartilage, tibial cartilage and patellar cartilage separately. First, an iterative procedure based on the feedback of the number of strong edges is designed to obtain an appropriate threshold for the Canny operator and to extract the bone-cartilage interface from MRI images. Second, the different edges are identified based on certain features, which allow for different cartilage to be distinguished synchronously. The cartilage is segmented preliminarily with minimum error Bayesian classifiers that have been previously trained. According to the cartilage edge and its anatomic location, the speed of segmentation is improved. Finally, morphological operations are used to improve the primary segmentation results. The cartilage edge is smooth in the automatic segmentation results and shows good consistency with manual segmentation results. The mean Dice similarity coefficient is 0.761.     

3.0T常规MRI在髋臼唇撕裂诊断中的价值

目的探讨3.0T常规MRI在髋臼唇撕裂中的诊断价值。方法临床入选64例高度怀疑髋臼唇撕裂患者,所有患者均先采用3.0T常规MRI检查,然后予以MR髋关节造影。结果 3.0T常规MRI检查组和MR髋关节造影组的髋关节各分区髋臼唇撕裂诊断情况比较没有统计学差异（P〉0.05）,两组的髋臼唇撕裂分型情况也无统计学差异（P〉0.05）。结论 3.0T常规MRI无创检查可以替代MR髋关节有创造影,对髋臼唇撕裂的临床诊疗具有一定的指导意义。     

肩髋膝关节软骨生物力学特性

研究了正常国人急性外伤致死的成人新鲜尸体肩髋膝关节软骨的力学性质.以一维拉伸的方法得出了肩髋膝关节软骨的破坏载荷、伸长比、Lagrange应力、Cauchy应变等.用最小二乘法对拉伸实验数据进行拟合,得出了肩髋膝关节的应力-应变关系表达式和应力-应变曲线;对肩髋膝关节软骨进行一维拉伸应力松弛实验,得出了应力松弛以及归一化后应力松弛函数数据和曲线,应用最小二乘法得出了肩髋膝关节的G(t).并对实验结果进行分析讨论.     

Higher Lesion Detection by 3.0T MRI in Patient with Transient Global Amnesia

Purpose

Transient global amnesia (TGA) patients were retrospectively reviewed to determine the usefulness of high-field strength MRI in detecting probable ischemic lesions in TGA.

Materials and Methods

We investigated the lesion detection rate in patients with TGA using 1.5T and 3.0T MRI. Acute probable ischemic lesions were defined as regions of high-signal intensity in diffusion weighted image with corresponding low-signal intensity in apparent diffusion coefficient map.

Results

3.0T MRI showed 11 out of 32 patients with probable ischemic lesions in the hippocampus with mean lesion size of 2.8 ± 0.6 mm, whereas 1.5T MRI detected no lesion in any of 11 patients. There were no significant differences in clinical characteristics between the groups of 1.5 and 3.0T MRI.

Conclusion

High-field strength MRI has a higher detection rate of probable ischemic lesions than low-field strength MRI in patients with TGA.     

Measurement of Articular Cartilage Thickness in the Articulated Knee

A radiographic and image analysis method was developed and applied in porcine knees for the measurement of articular cartilage thickness in articulated joints. The feasibility of the approach was assessed by implementing the method for the lateral femoral condyle from harvested limbs. Measurement of the undeformed cartilage thickness with this method was found to have a great degree of precision, with approximately a 1.0% (14 m) mean variation. Accuracy was also high when compared to an optical method for measuring the true cartilage thickness. An excellent linear correlation r² > 0.99) between the thickness determined optically and that obtained from the radiographic images was demonstrated. No significant differences were found between these two measures of cartilage thickness. This method, which minimizes disturbance to the structures of the knee to maintain its physiologic environment, also has promise to measure the changes in cartilage thickness as the tissue is deformed during joint loading. Information about the undeformed and deformed cartilage thicknesses can be combined with finite element models to examine cartilage behavior from both experimental and theoretical perspectives. © 1998 Biomedical Engineering Society. PAC98: 8759Hp, 0630Bp, 0705Pj     

Quantification of the triglyceride fatty acid composition with 3.0 T MRI

The aim of this work was to validate a sequential method for quantifying the triglyceride fatty acid composition with 3.0 T MRI. The image acquisition was performed with a 3D spoiled gradient multiple echo sequence. A specific phase correction algorithm was implemented to correct the native phase images for wrap, zero‐ and first‐order phase and rebuild the real part images. Then, using a model of a fat ¹H MR spectrum integrating nine components, the number of double bonds (ndb) and the number of methylene‐interrupted double bonds (nmidb) were derived. The chain length (CL) was obtained from these parameters using heuristic approximation. Validations were performed on different vegetable oils whose theoretical fatty acid composition was used as reference and in five human subjects. In vivo measurements were made in the liver and in the subcutaneous and visceral adipose tissues. Linear regressions showed strong correlations between ndb and nmidb quantified with MRI and the theoretical values calculated using oil composition. Mean ndb/nmidb/CL were 1.80 ± 0.25/0.51 ± 0.21/17.43 ± 0.07, 2.72 ± 0.31/0.94 ± 0.16/17.47 ± 0.08 and 2.53 ± 0.21/0.84 ± 0.14/17.43 ± 0.07 in the liver, subcutaneous and visceral adipose tissues respectively. The results suggest that the triglyceride fatty acid composition can be assessed in human fatty liver and adipose tissues with a clinically relevant MRI method at 3.0 T. Copyright © 2014 John Wiley & Sons, Ltd.     

Combined Ex Vivo 9.4T MRI and Quantitative Histopathological Study in Normal and Pathological Neocortical Resections in Focal Epilepsy

High‐resolution magnetic resonance imaging (MRI) may improve the preoperative diagnosis of focal cortical dysplasia (FCD) in epilepsy. Quantitative 9.4T MRI was carried out (T1, T2, T2* and magnetization transfer ratio) on 13 cortical resections, representing pathologically confirmed FCD (five cases) and normal cortex. Quantitative immunohistochemistry for myelination (myelin basic protein/SMI94), neuronal populations [microtubule‐associated protein 2 (MAP2), neurofilament (SMI31, SMI32), synaptophysin, NeuN, calbindin], reactive glia (GFAP), microglia (CD68) and blood–brain barrier permeability (albumin) was carried out in 43 regions of interest (ROI) from normal and abnormal white matter and cortex. MRI was spatially aligned and quantitative analysis carried out on corresponding ROI. Line profile analysis (LPA) of intensity gradients through the cortex was carried out on MRI and immunostained sections. An inverse correlation was noted between myelin/SMI94 and T1, T2 (P < 0.005) and T2* (P < 0.05; Spearman's correlation) and a positive correlation between neuronal MAP2 and T1 (P < 0.005) and T2* (P < 0.05) over all ROI. Similar pathology–MRI correlations were observed for histologically unremarkable white matter ROI only. LPA showed altered gradient contours in regions of FCD, reflecting abnormal cortical lamination and myelo‐architecture, including a preoperatively undetected FCD case. This study demonstrates the ability of quantitative 9.4T MRI to detect subtle differences in neuronal numbers and myelination in histologically normal appearing white matter and LPA in the evaluation of cortical dyslamination. These methods may be translatable to the in vivo detection of mild cortical malformations.     

骨性关节炎对膝关节软骨力学性质影响的实验研究

目的 研究正常国人新鲜尸体膝关节软骨和骨性关节炎膝关节软骨的生物力学性质,为临床提供生物力学参数。方法 取正常和病变的膝关节软骨在ShimadzuAUTOGRAPH电子万能试验机上进行一维拉伸实验。结果 得出了关节软骨最大载荷、伸长比、应力、应变等数据;用最小二乘法处理应力鄄应变数据,得出了其应力鄄应变关系表达式,拟合出了应力鄄应变曲线。结论 病变组各项力学性质指标均明显低于正常组。