基于磁共振T2-mapping成像评价长跑爱好者膝关节软骨厚度及软骨T2值的变化

目的:探究磁共振T2-mapping成像评价长跑爱好者膝关节软骨厚度及软骨T2值的变化。方法:2020年6月至2021年6月,抽取80例长跑爱好者为研究对象,在其跑步前24小时、10公里跑步后立即及休息24小时后进行磁共振T2-mapping成像评价,分析膝关节软骨恢复情况。结果:从影像学可以看出,10公里跑步后的膝关节内外侧胫骨中央区域、内外侧股骨髁中央区域软骨厚度、软骨T2值明显薄于/低于跑步前24h、休息24h后(P<0.05),但跑步前24H和休息24H后的膝关节内侧胫骨中央区域、内外侧股骨髁中央区域软骨厚度、软骨T2值比较无差异(P>0.05)。结论:患者的软骨厚度及软骨T2值患者发生一定变化,但在休息24h后基本恢复原来水平,为避免膝关节损伤,患者可尝试2天及以上长跑运动一次,保证长跑安全性。     

髌软骨T2-mapping成像:MRI正常与退变软骨的差异

目的 探讨1.5T MRI 0级髌软骨T2值的区域差异及其与性别、年龄间的关系,以及MRI 0级软骨与退变软骨T2值的差异。 方法 对452例患者以1.5T MR系统行常规膝关节检查后,采用6回波SE序列扫描完成髌骨轴位T2-mapping成像。对髌软骨进行MRI分级,测量并比较髌软骨最厚层面内侧、外侧、全层和病变处的T2值。 结果 MRI 0级髌骨内、外侧软骨和全层软骨的T2值差异无统计学意义(P=0.15)。髌软骨全层T2值与性别无相关性。>60岁者髌软骨T2值高于其他年龄组。当髌软骨退变时,Ⅰ~Ⅳ级T2-病变均明显高于T2-对照(P<0.001),T2-病变也明显高于MR 0级髌软骨的T2值(P<0.001)。Ⅰ~Ⅳ级髌软骨病变的T2值之间差异有统计学意义(P<0.001),且T2值随病变分级升高而增加。 结论 MRI 0级髌软骨全层T2值与性别无相关性,但随年龄增长而增加。髌软骨退变时T2值随病变严重程度而明显增加。MR T2-mapping成像对诊断和监测骨关节早期病变具有很高的临床价值。     

磁共振T2-mapping定量成像评估兔急性肠系膜上动脉缺血小肠肠壁损伤的实验研究

目的 探讨MRI T2-mapping定量成像对监测和评估兔小肠急性肠系膜上动脉缺血(acute mesenteric ischemia,AMI)肠壁损伤的诊断价值。材料与方法 将36只新西兰雄性白兔随机分为实验组(n=18)和对照组(n=18)。实验组行外科手术结扎第2～5支肠系膜动脉弧形血管网以及相应肠管两端供血血管,随后分别于6个时间点(1 h、2 h、3 h、4 h、5 h、6 h)进行MR T2-mapping成像,每个时间点3只。扫描完成后分别对3只兔施行安乐死,取出肠系膜动脉弧形血管网第3分支所供应的肠管病理标本,评估小肠肠壁缺血损伤的严重程度和病理特征变化。对照组进行假手术,开腹不做结扎处理。各个时间点实验组与对照组定量数值的差异采用独立样本t检验,两组各时间点T2值的组内比较采用单因素方差分析,用高斯拟合模型对T2值与缺血时间点进行拟合,显示小肠缺血肠壁的演变规律,并用病理组织学进行相关验证。T2值与缺血时间点间的拟合方程为f(x)=145×exp{-[(x-3.475)/4.297]²},拟合系数R²=0.79。结果 实验...     

长期体能训练后应用T2-mapping序列定量分析胫距关节软骨的变化

目的 探讨近半年体能训练后胫距关节软骨磁共振T2值的变化.材料与方法 分别选择年龄段为20～25岁的30名部队青年战士为试验组及健康青年志愿者作为对照组,在同等状态下进行T2-mapping序列扫描,将胫距关节先划分为内、中、外3个区域,每个区域再各自分为前、中、后3个区域,共9个区域,比较试验组与对照组各区域T2值的...     

肝脏恶性肿瘤扩散加权成像与T2加权成像对比研究

目的比较肝脏扩散加权成像(DWI)和T2WI反映肝脏恶性肿瘤扩散特征、病理特征及肿瘤范围的价值.方法回顾性研究肝脏恶性肿瘤44例48灶(肝细胞癌30例30灶,肝转移瘤10例14灶,胆管细胞癌4例4灶),比较DWI与T2WI图像液体(脑脊液,胆囊胆汁)和肝脏恶性肿瘤的信号,肿瘤/肝脏信号强度比(SIR),对比噪声比(CNR)以及肿瘤范围,测量肿瘤表观扩散系数(ADC)值.结果在b=600 s/mm2的图像中,所有病例的脑脊液均显示为低信号.肝脏恶性肿瘤多表现为高信号,其信号分布特征与T2WI不同;肿瘤的信号强度和瘤/肝SIR,DWI与T2WI不相关;DWI信号强度与ADC值呈负相关.DWI的病灶对比噪声比高于T2WI,二者差异有显著性.DWI显示病灶范围与T2WI差异无显著性.结论b=600 s/mm2的肝脏DWI图像受T2穿透效应影响较小,能够较好地反映肝脏恶性肿瘤的扩散特征.DWI肿瘤对比噪声比更高,有助于病灶边界的确定.DWI反映的肝脏恶性肿瘤的扩散特征,可作为其影像学特征之一.     

MRI T2-mapping检查在颈椎间盘退行性变程度评估中的应用价值研究

目的 探讨MRI T2-mapping检查在颈椎间盘退行性变程度评估中的价值。方法 选取2020年2月—2021年5月我院53例受检者行常规颈椎MRI及T2-mapping扫描,行颈椎间盘Pfirrmann分级及髓核T2值测定,分析髓核T2值与Pfirrmann分级的相关性,绘制受试者工作特征(ROC)曲线分析髓核T2值对Pfirrmann分级的诊断准确度,同时比较不同年龄段、颈椎间盘节段髓核T2值。结果 53例受检者共265个颈椎间盘,MRI髓核T2值随Pfirrmann分级升高而逐渐降低(P<0.01);不同Pfirrmann分级受检者MRI髓核T2值存在明显差异(P<0.05)。Spearman相关性分析显示,髓核T2值与Pfirrmann分级呈负相关(r=-0.673,P<0.01)。ROC曲线显示,髓核T2值诊断Ⅰ级和Ⅱ级、Ⅱ级和Ⅲ级、Ⅲ级和Ⅳ级颈椎间盘退行性变的准确度中等,曲线下面积分别为0.739、0.817及0.784。22～30岁受检者中,不同颈椎间盘节段MRI髓核T2值存在明显差异(P<0.01);31～45岁受检者不同颈椎间盘节段MRI髓核...     

定量磁共振T2映射成像在椎间盘退变中的研究进展

椎间盘退变是引起下腰背痛的主要原因之一,影像学的检查是诊断椎间盘退变的重要手段。传统MRI技术虽可显示椎间盘的信号强度和形态学改变,但很难客观量化椎间盘退变的程度。T2 mapping技术能够检测椎间盘内水含量、蛋白多糖含量及胶原纤维排列顺序等多种生化成分,为椎间盘退变早期临床评估提供新的方法。本文从T2 mapping与其他定量磁共振技术对比,及其与椎间盘退变分级、日本骨科学会评分、视觉模拟评分及年龄、性别等联系论述定量磁共振T2映射成像在椎间盘退变中的研究进展。     

肝脏T2值评估HBV相关慢加急性肝衰竭

目的 探讨肝脏T2值对HBV相关慢加急性肝衰竭的评估价值。方法 收集HBV相关慢加急性肝衰竭（HBV-ACLF）组、慢性乙型肝炎组和正常对照组,分别对3组受检者行多回波梯度-自旋回波（M-GRASE）序列扫描,获得T2图,并计算肝脏平均T2值及T2弛豫率（R2）。收集HBV-ACLF组和慢性乙型肝炎组MR检查前2天内肝功能血液生化指标。比较3组间T2和R2值的差异及T2值与生化指标的相关性,采用ROC曲线评价T2值对HBV-ACLF的诊断效能。结果 3组间T2值（χ²=19.074,P<0.001）和R2值（F=10.411,P<0.001）差异均有统计学意义。T2值诊断慢加急性肝衰竭曲线下面积为0.86（P<0.001）,诊断阈值为57.73 ms（R2=0.017）。T2值与凝血酶原时间国际标准化比值（INR）、凝血酶原时间（PT）及透明质酸（HA）呈中度正相关（r_s=0.65、0.67、0.39,P均<0.05）,与凝血酶原活动度（PTA）、白蛋白（ALB）、前白蛋白（PA）呈中度负相关（r_s=-0.67、-0.48、-0.37,P均<0.05）。结论 T2或R2值可较好地反映肝脏功能情况,并与较多的肝功能实验室指标均具有相关性,对HBV-ACLF具有较好的诊断效能。     

乳腺癌磁共振T2＊W首次通过灌注成像研究进展

影像学检查在乳腺癌早期筛查中起重要作用。T2＊W首次通过灌注成像是一种研究病变组织微血管灌注情况的功能性成像方法，可测定局部病变组织的血流量及血容量。本文就T2＊W首次通过灌注成像研究进展作一综述。     

应用磁共振T2-mapping成像评价非专业马拉松运动员膝关节软骨改变

目的：应用磁共振T2-mapping成像评价马拉松普通参与者膝关节软骨厚度及软骨T2值的变化.材料与方法：对13名参加马拉松赛的健康志愿者的13个膝关节在赛前及赛后行膝关节3.0T磁共振成像,年龄24 ～40岁,平均（32±6.3）岁,应用T2-mapping成像观察和测量股骨内外髁与胫骨平台负重区及非负重区软骨浅、深层的平均T2值,同时测量各区域软骨厚度,并进行统计学分析.结果：磁共振常规序列成像示膝关节在赛前与赛后无明显变化.T2-mapping成像示关节软骨浅层T2值在赛前及赛后均高于深层,差异有统计学意义（P＜0.05）;赛后浅层软骨T2值低于赛前,差异有统计学意义（P＜0.05）;关节软骨同一区域比较,负重区软骨厚度赛后低于赛前.结论：磁共振T2-mapping成像可以量化评估关节软骨内组织成分的变化,马拉松赛前及赛后关节软骨浅层T2值均高于深层,马拉松赛后负重区软骨厚度及浅层软骨T2值减低.     

Cardiac T2-mapping using a fast gradient echo spin echo sequence - first in vitro and in vivo experience

Background

The aim of this study was the evaluation of a fast Gradient Spin Echo Technique (GraSE) for cardiac T2-mapping, combining a robust estimation of T2 relaxation times with short acquisition times. The sequence was compared against two previously introduced T2-mapping techniques in a phantom and in vivo.

Methods

Phantom experiments were performed at 1.5 T using a commercially available cylindrical gel phantom. Three different T2-mapping techniques were compared: a Multi Echo Spin Echo (MESE; serving as a reference), a T2-prepared balanced Steady State Free Precession (T2prep) and a Gradient Spin Echo sequence. For the subsequent in vivo study, 12 healthy volunteers were examined on a clinical 1.5 T scanner. The three T2-mapping sequences were performed at three short-axis slices. Global myocardial T2 relaxation times were calculated and statistical analysis was performed. For assessment of pixel-by-pixel homogeneity, the number of segments showing an inhomogeneous T2 value distribution, as defined by a pixel SD exceeding 20 % of the corresponding observed T2 time, was counted.

Results

Phantom experiments showed a greater difference of measured T2 values between T2prep and MESE than between GraSE and MESE, especially for species with low T1 values. Both, GraSE and T2prep resulted in an overestimation of T2 times compared to MESE. In vivo, significant differences between mean T2 times were observed. In general, T2prep resulted in lowest (52.4 ± 2.8 ms) and GraSE in highest T2 estimates (59.3 ± 4.0 ms). Analysis of pixel-by-pixel homogeneity revealed the least number of segments with inhomogeneous T2 distribution for GraSE-derived T2 maps.

Conclusions

The GraSE sequence is a fast and robust sequence, combining advantages of both MESE and T2prep techniques, which promises to enable improved clinical applicability of T2-mapping in the future. Our study revealed significant differences of derived mean T2 values when applying different sequence designs. Therefore, a systematic comparison of different cardiac T2-mapping sequences and the establishment of dedicated reference values should be the goal of future studies.     

腰椎间盘退变的磁共振T2 map定量研究

目的 探讨T2 map成像定量评价早期腰椎间盘退变的价值。方法 对46名受试者行腰椎MR矢状位T2WI及正中矢状位T2 map成像,根据Pfirrmann标准将L₁-S₁椎间盘分级,并测量髓核及纤维环前后缘T2值。分别比较各级髓核和纤维环前后缘T2值,对髓核和纤维环前后缘T2值与年龄、退变分级的相关性进行分析。采用单因素方差分析和Pearson相关分析。结果 共计测量229个椎间盘:①各分级腰椎间盘髓核T2值随分级增高而减小,除Ⅳ级与Ⅴ级,余各级间差异均有统计学意义(P<0.05);②各分级腰椎间盘纤维环前缘T2值呈上升趋势,除Ⅰ级、Ⅱ级与Ⅳ级,余各级间差异均无统计学意义(P＞0.05);③腰椎间盘髓核T2值与受试者年龄呈显著负相关(P<0.01),纤维环前、后缘T2值与受试者年龄无明显相关性(P＞0.01)。结论 基于T2 map成像定量测定腰椎间盘髓核T2值的变化是一种无创评价椎间盘早期退变的方法。     

应用MRI研究腰背肌退变规律和特征

目的应用MRI研究腰背肌退行性变规律及影像特征并探讨其临床价值。方法研究对象为2007年1月至2009年3月来解放军第175医院影像科做MRI体检的体检者,按性别分组,每组再按年龄分为1～10岁、11～20岁、21—30岁、31～40岁、41—50岁、51～60岁、61～70岁、71岁以上8个组,共有16个研究组,每个研究组20例（从各年龄段中随机抽取）,共320例。评价指标包括：（1）腰背肌厚度;（2）皮下脂肪与腰背竖脊肌MR信号比值;（3）多裂肌形态、信号及肌间隙的改变。对腰背肌厚度值和皮下脂肪与腰背肌MR信号比值在不同性别间及不同年龄段间的差异应用Excel 2003 T-TEST返回Student’s t检验的概率值,样本为成对检验。多裂肌形态、信号、肌间隙改变在不同年龄段间的差异应用多样本比较的秩和Kruskal-Wallis检验。取单侧P〈0．05时,表示差异有统计学意义。结果除1～10岁年龄段外,其余每个年龄段男性组腰背肌平均厚度均大于女性组,差异具有统计学意义（P=0．002）。腰背肌厚度自1—30岁逐渐长大饱满,在30—70岁处于成熟的稳定状态,到70岁以后开始退变、萎缩、变细。皮下脂肪与腰背竖脊肌MR信号比值,男性组平均值大于女性组,差异具有统计学意义（P=0．024）,此比值自婴幼儿期开始逐渐增大,男性组在20～60岁趋于稳定状态,在60岁以后急速下降,而女性组在20—40岁趋于稳定状态,在40岁以后急速下降。在形态结构方面,年轻组多裂肌表现为形态饱满、轮廓平整、均匀低信号、肌内间隙不显示或呈单个线状或点状显示;老年组多裂肌表现为形态萎缩、轮廓凹陷、信号不均匀性增高、肌内间隙呈多发线片状、羽毛状或网格状显示。各种观察指标在不同年龄组间的差异具有统计学意义。结论腰背肌生理性退变,女性早于男性,肌内脂肪变性早于肌形态学改变。主要MRI表现包括：肌肉萎缩造成肌肉变细、形态萎缩、轮廓萎陷;肌内不均匀性脂肪浸润,造成信号不均性增高,皮下脂肪信号与肌肉信号比值下降,肌内间隙呈线片状、羽毛状或网格状。     

Non-contrast T1-mapping detects acute myocardial edema with high diagnostic accuracy: a comparison to T2-weighted cardiovascular magnetic resonance

Background

T2w-CMR is used widely to assess myocardial edema. Quantitative T1-mapping is also sensitive to changes in free water content. We hypothesized that T1-mapping would have a higher diagnostic performance in detecting acute edema than dark-blood and bright-blood T2w-CMR.

Methods

We investigated 21 controls (55 ± 13 years) and 21 patients (61 ± 10 years) with Takotsubo cardiomyopathy or acute regional myocardial edema without infarction. CMR performed within 7 days included cine, T1-mapping using ShMOLLI, dark-blood T2-STIR, bright-blood ACUT2E and LGE imaging. We analyzed wall motion, myocardial T1 values and T2 signal intensity (SI) ratio relative to both skeletal muscle and remote myocardium.

Results

All patients had acute cardiac symptoms, increased Troponin I (0.15-36.80 ug/L) and acute wall motion abnormalities but no LGE. T1 was increased in patient segments with abnormal and normal wall motion compared to controls (1113 ± 94 ms, 1029 ± 59 ms and 944 ± 17 ms, respectively; p < 0.001). T2 SI ratio using STIR and ACUT2E was also increased in patient segments with abnormal and normal wall motion compared to controls (all p < 0.02). Receiver operator characteristics analysis showed that T1-mapping had a significantly larger area-under-the-curve (AUC = 0.94) compared to T2-weighted methods, whether the reference ROI was skeletal muscle or remote myocardium (AUC = 0.58-0.89; p < 0.03). A T1 value of greater than 990 ms most optimally differentiated segments affected by edema from normal segments at 1.5 T, with a sensitivity and specificity of 92 %.

Conclusions

Non-contrast T1-mapping using ShMOLLI is a novel method for objectively detecting myocardial edema with a high diagnostic performance. T1-mapping may serve as a complementary technique to T2-weighted imaging for assessing myocardial edema in ischemic and non-ischemic heart disease, such as quantifying area-at-risk and diagnosing myocarditis.     

磁共振T2 mapping技术在体部恶性肿瘤中的研究进展

随着磁共振影像技术及大数据的快速发展,肿瘤的影像诊断不仅仅是局限于影像表现,如何将肿瘤病灶的特性进行定量成像评价逐渐成为研究的热点。目前,T1加权成像(T1 weighted imaging,T1WI)、T2加权成像(T2 weighted imaging,T2WI)、弥散加权成像(diffusion weighted imaging,DWI)及动态增强(dynamic contrast enhancement,DCE)技术已经成为磁共振检查的常规序列,各加权序列图上信号强度的大小仅能间接反映组织的特性。T2 mapping成像技术是定量成像技术中的一种,具有客观性、较好的可重复性及稳定性,在骨关节炎和心肌水肿中的运用和研究较多。随着技术的发展及体部肿瘤发病率的逐年升高,近年来也逐渐开始被应用到体部肿瘤方面的研究,作者就T2 mapping在体部恶性肿瘤中的定量研究进展予以综述。     

磁共振T1 mapping成像评价肥厚型和扩张型心肌病弥漫性心肌纤维化

目的 探讨磁共振纵向弛豫时间定量(T1 mapping)成像评价肥厚型心肌病(HCM)和扩张型心肌病(DCM)心肌纤维化的价值,及心肌纤维化与左心室射血分数的关系。方法 收集经临床诊断证实的30例HCM患者(HCM组)、27例DCM患者(DCM)和符合纳入标准的33例患者(对照组)。对所有受检者均行心脏电影成像、对比增强前、后T1 mapping成像、延迟对比增强(LGE)成像。测量不同受检者增强前、后左心室平均T1值及心功能参数并进行统计学分析,分析心肌平均T1值与心功能指标的相关性。结果 HCM组22例(22/30,73.33%)患者存在延迟强化,DCM组15例(15/27,55.56%)患者存在延迟强化,对照组无延迟强化。比增强前,HCM组[(1294.79±85.22)ms]、DCM组[(1312.88±59.57)ms]左心室心肌T1值均较对照组[(1266.56±57.33)ms]显著增加(P均<0.05);对比增强后,HCM组[(491.31±121.59)ms]、DCM组[(466.77±126.34)ms]左心室心肌T1均值较对照组[(534.09±92.73)]显著减低(P均<0.05)。HCM患者左心室心肌增强前T1值与左心室射血分数呈负相关(r=-0.58,P<0.05),增强后T1值与其呈正相关(r=0.59,P<0.05);DCM患者左心室心肌增强前T1值与左心室射血分数呈负相关(r=-0.55,P<0.05),增强后T1值与其呈正相关(r=0.51,P<0.05)。结论 HCM和DCM患者心肌纤维化与心功能相关;T1 mapping成像有助于评价HCM和DCM患者心肌纤维化。     

The reliability of paraspinal muscles composition measurements using routine spine MRI and their association with back function

This study examines the reliability of quantitative and qualitative muscle composition measurements of paraspinal muscle cross-sectional areas (CSAs) from routine lumbar spine magnetic resonance images and their association with maximal isokinetic lifting performance. The extent of paraspinal muscle composition reflects back function is currently not known. Measurements were repeated 4–8 weeks apart and different measurements of related constructs were compared. Participants were a population-based sample of 169 males, 35–67 years old, without considering the presence or absence of a history of low back pain or related problems in the selection of subjects. The quantitative and qualitative muscle composition measurements for axial magnetic resonance (MR) images of paraspinal muscles at the L3–L4 lumbar spine level, isokinetic lifting force and work, and body fat percentage were the main outcome measures. Results showed that the reproducibility of different paraspinal muscle composition measurements at the L3–L4 level was excellent for CSAs (ICC=0.95–0.99) and quantitative muscle composition measurements using cerebrospinal fluid adjusted signal intensity (ICC=0.96–0.99), and moderate for qualitative muscle composition ratings (Kappa=0.54–0.76). The correlations of the quantitative and qualitative muscle composition measurements with isokinetic lifting force and work were generally low (r=0.02–0.41), and favoured the qualitative assessments. In conclusion, quantitative and qualitative muscle composition measurements of paraspinal muscles are highly reproducible tissue measures, have low associations with body fat and isokinetic lifting performance, and show that paraspinal muscle morphology using routine spine magnetic resonance imaging (MRI) is poorly related to back function.     

前列腺癌的MRI诊断：T2WI、DWI、MRS及其综合应用

目的以病理结果为参照,探讨T2WI、DWI及MRS三种成像方法及其综合应用对前列腺癌定性诊断的价值。方法 42例患者在1.5T磁共振仪上采用体部矩阵线圈结合脊柱矩阵线圈行T2WI、DWI及3DCSI1H-MRS扫描,所有病例均经直肠穿刺活检证实。按照前列腺6分区法将所得图像数据分区评估测量,采用5分制针对各分区评分,并与病理结果对照。对三种扫描方法各自所得数据以及三种方法综合评分分别做ROC曲线分析比较,计算各组方法诊断的敏感性、特异性及准确性等。结果 42例病例中15例经穿刺证实为前列腺癌,27例为前列腺良性病变。252个分区均得到病理证实,其中201个为良性,51个为恶性。各组诊断方法的敏感性、特异性及ROC曲线下面积（Az）如下：T2WI：88.2%、67.2%和0.848±0.030,最佳诊断界值为3;DWI：82.4%、81.6%和0.860±0.033,最佳诊断界值为4;MRS：84.3%、98.0%和0.961±0.016,最佳诊断界值为5;三者综合：96.1%、96.5%和0.978±0.009,最佳诊断界值为4。结论 T2WI、DWI及MRS三种方法均可以独立有效诊断前列腺癌。三种成像方法结合诊断前列腺癌的准确性显著高于三种成像技术独立诊断,其诊断结果与病理分析一致性较好。在三种成像技术中,MRS的诊断价值较高。