基于定量动态负荷下膝关节骨性关节炎软骨MRIT2时间表现研究

目的通过比较膝关节骨性关节炎（OA）病人定量动态负荷前后膝关节软骨T2时间变化情况,分析MRIT2mapping序列反映软骨基质生物力学变化的灵敏度．并验证高磁场条件下人体关节负荷装置的有效性。方法10例膝关节OA病人,其中男性3例．女性7例：年龄4l～66岁．平均年龄57-3岁。依托人体下肢关节力学负荷装置,对其施加膝关节动态负荷。负荷前后行膝关节MRIT2maDping成像,将膝关节轴向负荷区软骨分为4个部位：胫骨平台内、外侧软骨区及股骨内、外侧髁软骨区．分别测量各部位软骨负荷前后的T,时间。对负荷前膝关节内、外侧软骨分级评估进行卡方检验,对同一软骨区动态负荷前后的T2时间进行配对t检验。结果负荷前膝关节内外侧软骨分级差异无统计学意义（P〉0．05）。OA病人负荷前后T2值,胫骨平台内侧软骨区分别为（39．59±4．17）ms、（40．14±4．49）ms（f=0．426,P=0．680）;胫骨平台外侧软骨区（38．85±6．72）ms、（41．25±6．54）ms（t=1．704,P=0．123）：股骨内侧髁软骨区（36．44±5．72）ms、（40．63±4．90）ms（t=1．783,P=0．108）;股骨外侧髁软骨区（39．30±5．78）ms、（46．14±5．03）ms（t=2．826,P=0．020）。结论OA病人负荷后膝关节局部区域软骨区T2时间延长．自行设计的动态加压装置适合在高磁场条件下完成加压及MRI检查,有一定推广意义。     

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。     

T_2 mapping评价关节软骨损伤及修复的研究进展

T2mapping是近年来发展的MRI新技术,能间接反应关节软骨结构及组织学成分的变化,发现关节软骨形态学变化之前的组织学改变。笔者就T2mapping成像原理、软骨损伤的组织学表现,以及成像影响因素等方面作一综述,重点介绍了T2mapping在软骨损伤、退变、修复等方面的研究进展,并展望了T2mapping未来发展前景。     

低场强磁共振在膝关节软骨损伤的诊断价值

目的探讨低场四肢专用MR对膝关节软骨损伤的诊断价值。方法收集我院经关节镜证实膝关节软骨损伤79例,全部病例均行低场强四肢专用MRI常规检查,对照分析膝关节软骨损伤的MRI表现和关节镜结果。结果低场MRI对软骨损伤诊断的敏感性、特异性、准确性分别为84%、86%、85%。结论低场四肢专用MRI对膝关节软骨损伤诊断有一定价值。     

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。     

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。     

葡聚糖包裹超顺磁性氧化铁纳米材料用于关节软骨磁共振T2-Map成像研究

本研究制备了粒径(18±2)nm的葡聚糖包裹的超顺磁性氧化铁纳米颗粒,作为磁共振T2造影剂,对兔关节软骨进行增强磁共振T2-Map成像,并分析注射前后24 hT2弛豫时间的变化,发现T2弛豫时间均下降。行组织病理学普鲁士兰染色,发现软骨基质及细胞内均有氧化铁纳米颗粒的存在,说明葡聚糖包裹超顺磁性氧化铁纳米材料可应用于关节软骨磁共振增强成像。     

3D-FS-SPGR序列在膝关节软骨病变的临床应用研究

目的　利用3D-FS-SPGR序列测量各期膝关节OA软骨厚度,探讨OA膝关节软骨厚度与病变进展的关系。 方法　62例OA患者行膝关节MRI检查,用3D-FS-SPGR序列测量不同部位关节软骨的厚度,并与20名对照组膝关节MRI检查结果进行比较。 结果　轻度OA组关节软骨厚度与正常组之间无统计学差异（P＞0.05）,而重度OA组大部分软骨区域软骨厚度与正常组有统计学差异（P＜0.05）。软骨厚度的改变可能受到多方面因素的影响,年龄、体重及BMI等与软骨厚度改变之间存在负相关。 结论　关节软骨负重面大部分区域随着OA病情的加重,其软骨厚度变薄,软骨厚度改变可能还受到体重、年龄及性别等因素的影响。     

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.     

Morphological MRI and T2 mapping of cartilage repair tissue after mosaicplasty with tissue-engineered cartilage in a pig model

The aim of this study was to evaluate the efficacy of mosaicplasty with tissue-engineered cartilage for the treatment of osteochondral defects in a pig model with advanced MR technique. Eight adolescent miniature pigs were used. The right knee underwent mosaicplasty with tissue-engineered cartilage for treatment of focal osteochondral defects, while the left knee was repaired via single mosaicplasty as controls. At 6, 12, 18 and 26 weeks after surgery, repair tissue was evaluated by magnetic resonance imaging （MRI） with the cartilage repair tissue （MOCART） scoring system and T2 mapping. Then, the results of MRI for 26 weeks were compared with findings of macroscopic and histologic studies. The MOCART scores showed that the repaired tissue of the tissue-engineered cartilage group was statistically better than that of controls （P 〈 0.001）. A significant correlation was found between macroscopic and MOCART scores （P 〈 0.001）. Comparable mean T2 values were found between adjacent cartilage and repair tissue in the experimental group （P 〉 0.05）. For zonal T2 value evaluation, there were no significant zonal T2 differences for repair tissue in controls （P 〉 0.05）. For the experimental group, zonal T2 variation was found in repair tissue （P 〈 0.05）. MRI, macroscopy and histology showed better repair results and bony incorporation in mosaicplasty with the tissue-engi- neered cartilage group than those of the single mosaicplasty group. Mosaicplasty with the tissue-engineered cartilage is a promising approach to repair osteochodndral defects. Morphological MRI and T2 mapping provide a non-invasive method for monitoring the maturation and integration of cartilage repair tissue in vivo.     

Cost-effectiveness of magnetic resonance imaging of the knee for patients presenting in primary care

Background

Musculoskeletal problems generate high costs. Of these disorders, patients with knee problems are commonly seen by GPs. Magnetic resonance imaging (MRI) of the knee is an accurate diagnostic test, but there is uncertainty as to whether GP access to MRI for these patients is a cost-effective policy.

Aim

To investigate the cost-effectiveness of GP referral to early MRI and a provisional orthopaedic appointment, compared with referral to an orthopaedic specialist without prior MRI for patients with continuing knee problems.

Design of study

Cost-effectiveness analysis alongside a pragmatic randomised trial.

Setting

Five-hundred and thirty-three patients consulting their GP about a knee problem were recruited from 163 general practices at 11 sites across the UK.

Method

Two-year costs were estimated from the NHS perspective. Health outcomes were expressed in terms of quality-adjusted life years (QALYs), based on patient responses to the EQ–5D questionnaire administered at baseline, and at 6, 12, and 24 months’ follow-up.

Results

Early MRI is associated with a higher NHS cost, by £294 ($581; €435) per patient (95% confidence interval [CI] = £31 to £573), and a larger number of QALYs, by 0.050 (95% CI = −0.025 to 0.118). Mean differences in cost and QALYs generated an incremental cost per QALY gained of £5840 ($11 538; €8642). At a cost per QALY threshold of £20 000, there is a 0.81 probability that early MRI is a cost-effective use of NHS resources.

Conclusion

GP access to MRI for patients presenting in primary care with a continuing knee problem represents a cost-effective use of health service resources.     

Indications requiring preoperative magnetic resonance imaging before knee arthroscopy

Introduction

Knee arthroscopy knee is gold standard in diagnosis and simultaneous treatment of knee disorders. But most patients undergo magnetic resonance imaging (MRI) before arthroscopy, although MRI results are not always consistent with arthroscopic findings. This raises the question in which suspected diagnoses MRI really has influence on diagnosis and consecutive surgical therapy.

Material and methods

Preoperative MRI of 330 patients with knee disorders were compared with arthroscopic findings. The MRI were performed by 23 radiologists without specialization in musculoskeletal diagnostics. Specificity, sensitivity, negative/positive predictive value and accuracy of MRI were calculated in comparison to arthroscopic findings.

Results

We found sensitivity/specificity of 58%/93% for anterior horn, 94%/46% for posterior horn of medial meniscus and 71%/81% for anterior and 62%/82% for posterior horn of lateral meniscus. Related to anterior cruciate ligament injuries we showed sensitivity/specificity of 82%/91% for grade 0 + I and 72%/96% for grade II + III. For Cartilage damage sensitivity/specificity of 98%/7% for grade I-, 89%/29% for grade II-, 96%/38% for grade III- and 96%/69% for grade IV-lesions were revealed.

Conclusions

The MRI should not be used as routine diagnostic tool for knee pain. No relevant information for meniscal lesions and anterior cruciate ligament ruptures has been gained with MRI from non-specialized outside imaging centres.The MRI should not be used as routine diagnostic tool for knee pain. No relevant information for meniscal lesions and anterior cruciate ligament ruptures has been gained with MRI from non-specialized outside imaging centres.     

核磁共振超短回波时间序列技术研究进展

核磁共振成像（MRI）技术拥有良好的软组织分辨率且无电离辐射,在临床和科研方面均得到了广泛应用。超短回波时间序列（UTE）在一定程度上弥补了MRI在短T2组织成像的弱点,使MRI的应用更加广泛。由UTE得到的派生序列有脂肪抑制UTE、单绝热反转恢复UTE、双回波差UTE等。本文介绍核磁共振超短时间回波序列（MR-UTE）技术的发展、原理及其应用,并对MR-UTE技术的发展方向进行展望。     

短T2组织磁共振成像技术研究进展

常规磁共振有较好的软组织对比度,但对骨、关节、软骨、肌腱等短T2组织（约小于10 ms）的分辨能力欠佳。可通过 增强短T2组织的图像对比度（利用魔角效应和注射造影剂）、开发专用的短T2组织成像技术（可变回波时间成像、超短回波 时间成像和零回波时间成像）和抑制周围长T2组织来获得较高质量的短T2组织图像。近年来,定量磁共振成像技术因其 能精准地反映与病变相关的生化参数特征也被应用于短T2组织病变的临床诊断。本研究主要从增强短T2组织对比度、缩 短序列回波时间和长T2组织抑制等3个方面回顾了短T2组织磁共振成像的常规方法,并对短T2组织的定量磁共振成像技 术进行了系统的分析和展望。     

人体膝关节股骨后髁角度的MRI测量

背景：全膝关节置换过程中股骨假体旋转力线良好非常重要,研究显示后髁角度是确定力线的重要依据,后髁角度为股骨后髁轴与股骨手术髁上轴之间角度,MRI测量可清晰显示后髁软骨、外上髁突起及内上髁凹陷,从而保证测量数据的准确。 目的：测量保定北部地区人群中膝关节后髁角度,为临床实施全膝关节置换过程中确定股骨假体旋转力线提供影像学依据。 方法：应用核磁共振机对入选中青年人群膝关节进行扫描,取膝关节伸直中立位,扫描平面垂直于膝关节机械轴,选择T1像上最佳膝关节轴位平面,由两名观察者独自分析图像,通过Bravo viewer 6.0影像软件观察股骨内上髁存在率,画出股骨髁上轴线及后髁线并测量两条轴线之间角度,即股骨后髁角度。 结果与结论：入选人群男性股骨后髁角度为(2.73±1.28)°,女性股骨后髁角度为(2.35±1.37)°,不同性别间差异无显著性意义。提示MRI测量股骨后髁角具有较大优越性,人工全膝关节置换过程中髁上轴线变异性较小,可参照后髁角度定位安装股骨假体,避免膝关节置换后并发症发生。中国组织工程研究杂志出版内容重点：人工关节;骨植入物;脊柱;骨折;内固定;数字化骨科;组织工程全文链接：     

Effectiveness of GP access to magnetic resonance imaging of the knee: a randomised trial

Background

GPs commonly see patients with knee problems. Magnetic resonance imaging (MRI) of the knee is an accurate diagnostic test for meniscus and ligament injuries of the knee, but there is uncertainty about the appropriate use of MRI and when it should enter the diagnostic pathway for patients with these problems.

Aim

To assess the effectiveness of GP referral to early MRI and a provisional orthopaedic appointment, compared with referral to an orthopaedic specialist without prior MRI for patients with continuing knee problems.

Design of study

Pragmatic multicentre randomised trial with two parallel groups.

Setting

A total of 553 patients consulting their GP about a continuing knee problem were recruited from 163 general practices at 11 sites across the UK.

Method

Patients were randomised to MRI within 12 weeks of GP referral including a provisional orthopaedic appointment, or orthopaedic appointment without prior MRI within a maximum of 9 months from GP referral. The primary outcome measures were the Short Form 36-item (SF-36) physical functioning scale and the Knee Quality of Life 26-item Questionnaire (KQoL-26) at 6, 12, and 24 months.

Results

Patients randomised to MRI improved mean SF-36 physical functioning scores by 2.81 (95% confidence interval [CI] = −0.26 to 5.89) more than those referred to orthopaedics (P = 0.072). Patients randomised to MRI improved mean KQoL-26 physical functioning scores by 3.65 (95% CI = 1.03 to 6.28) more than controls (P = 0.007). There were no other significant differences.

Conclusion

GP access to MRI yielded small, but statistically significant, benefits in patients'' knee-related quality of life but non-significant improvements in physical functioning.