This study aimed to investigate the association of thigh muscle fat infiltration by quantitative MRI with muscle strength in patients with type 2 diabetes mellitus (T2DM). Seventy T2DM patients and sixty control subjects (71 males; age: 52 ± 8 years) underwent 3.0T MRI and isokinetic muscle strength measurements to obtain the skeletal muscle index (SMI), intermuscular adipose tissue (IMAT) proton density fat fraction (PDFF), intramuscular fat (IMF) PDFF, peak torque (PT) and total work (TW) of knee extensors and flexors. The differences of measurements between T2DM patients and asymptomatic volunteers were compared. Multivariate regression analysis was used to determine significant predictors of thigh extension and flexion strength. The SMI, IMAT and IMF PDFF of thigh muscles in T2DM patients were higher than that in the control group ( p < 0.001), while PT and TW were lower than those in the control subjects ( p < 0.05). Both IMF and IMAT PDFF were negatively correlated with PT, TW in participants with T2DM (extensors: r = − 0.72, − 0.70, p < 0.001; r = − 0.62, − 0.56, p < 0.05. flexors: r = − 0.37, − 0.43, p < 0.05; r = − 0.39, − 0.46, p < 0.05). Moderate and strong correlations between HOMA-IR and muscle strength measurements, muscle PDFFs were observed in extensors and flexors. IMF PDFF and age were the statistically significant predictor of PT and TW of extensors of thigh in multivariate regression analysis. Therefore, the thigh muscle PDFF increased was associated with muscle strength decreased in T2DM patients beyond SMI. Age are also important factors influencing thigh muscle PDFF and strength in T2DM patients.

目的 探讨血氧水平依赖磁共振成像(BOLD-MRI)评估 2 型糖尿病(T2DM)患者下肢骨骼肌微血管病变的临床价值.方法 前瞻性选取T2DM合并下肢骨骼肌微血管病变患者 40 例(DM+MC组),同时招募年龄、性别相匹配的 40 例志愿者(正常对照组)行大腿 MR扫描.根据解剖学分区将大腿划分为前外侧群、后群和内收肌群,且根据病程将DM+MC组患者分为初诊组、病程≤5 年组和病程>5 年组,分别测量和比较T2DM各组与正常对照组大腿肌肉的平均R2 *及T2 *值.结果 DM+MC组患者大腿骨骼肌平均R2 *和T2 *值与正常对照组相比无统计学差异(P>0.05);而DM+MC病程>5 年组患者大腿肌肉平均R2 *值高于其余 3 组,平均T2 *值低于其余 3 组,差异均有统计学意义(P<0.05);DM+MC组内大腿各肌群 R2 *值后群>内收肌群>前外侧群,各肌群T2 *值后群0.05).结论 BOLD-MRI有助于定量评估T2DM患者骨骼肌微血管病变,T2DM患者大腿骨骼肌微循环改变与病程有关,且 DM+MC患者大腿后肌群微循环更易受损.

Objective:To assess the difference in the content of intermuscular and intramuscular fat infiltration in thigh between patients with type 2 diabetes mellitus（T2DM） and healthy volunteers by quantitative MRI 3D-IDEAL-IQ,and to analyze its distribution.Methods:23 male and 20 female patients diagnosed with T2DM（T2DM group） and 40 age and gender-matched healthy volunteers（control group, 20 males, 20 females） were enrolled.Mid-thigh MRI scans were performed on all subjects.The subcutaneous fat area and intermuscular fat area were measured respectively and the intramuscular fat area and pure muscle area were calculated by each muscle fat fraction.Then the thigh muscles were divided into different muscle groups according to anatomical division, and the intramuscular fat area and pure muscle area of each muscle group were calculated respectively.Results:The T2DM group had a higher absolute value of areas of subcutaneous fat（P=0.004）,intermuscular fat（P＜0.001） and intramuscular fat（P＜0.001） than the control group.Compared to the control group, the T2DM group had a larger relative value of intramuscular fat area（P＜0.001） and a smaller relative value of pure muscle area（P=0.044）,especially in the anterolateral muscle group（P=0.003）.Conclusions:3D-IDEAL-IQ quantitative technique can be used to evaluate the content and distribution of the intermuscular and intramuscular fat infiltration in the thigh of T2DM patients.The ratio of fat and muscle in thigh skeletal muscle changes in those T2DM patients, with fat increased and muscle decreased and the muscles of the anterolateral group severely involved.

目的 探讨X线透视引导下穿刺大鼠腰椎间盘建立椎间盘源性腰痛(DLBP)动物模型的可行性.方法 将60只Sprague-Dawley大鼠随机分为DLBP组(X线透视引导下穿刺L4～5和L5～6,n=24)、假手术组(穿刺同层面椎旁肌,n=15)、正常组(不做任何处理,n=21);根据建模时间,再将每组大鼠平均分为30 d组、90 d组、180 d组.分别在建模后1、7、14、30、90、180 d进行行为学实验,评估大鼠步态功能、痛温觉阈值、轴性腰痛的改变;建模后30、90、180 d进行腰椎MR矢状位T2加权成像扫描,扫描完成后处死大鼠截取L4～5和L5～6椎间盘,行苏木精-伊红(HE)染色和番红O-固绿染色观察椎间盘退变程度.结果 DLBP组建模后大鼠步态障碍评分呈先增高后恢复再增高改变,至90、180 d与正常组和假手术组相比大鼠行为学表现为痛温觉阈值显著减低(均P＜0.01)、轴性腰痛诱发的弯腰时间增加及挣扎时间减少(均P＜0.05).腰椎MR矢状位T2加权成像显示,建模后30、90、180 d正常组和假手术组大鼠腰椎间盘T2信号均无降低,而DLBP组腰椎间盘T2信号均降低,Pfirrmann分级以Ⅲ～Ⅳ级为主,呈中-重度退变.组织学结果显示,DLBP组大鼠椎间盘退变Masuda评分显著高于正常组和假手术组(均P＜0.05).结论 X线透视引导下腰椎间盘穿刺技术便捷、高效、微创,成功建立了 DLBP大鼠模型.

目的:探讨磁共振血氧水平依赖(BOLD)和T2-mapping成像技术评价盘源性腰痛大鼠椎旁肌功能改变的潜在价值.方法:在X线透视引导下使用26 G针头经左侧后入路穿刺大鼠L4-5和L5-6椎间盘,向髓核内注射PBS溶液2.5μL,构建SD大鼠盘源性腰痛模型(18只);正常对照组大鼠(18只)不做特殊处理.于造模后1天、1周、2周、1个月分别对36只大鼠进行行为学评价,包括步态分析、热板实验、丙酮实验和悬尾实验.造模后1个月对36只大鼠进行3.0T MRI扫描,包括T2-mapping和BOLD序列,测量L4-5和L5-6层面双侧椎旁肌(多裂肌、竖脊肌和腰大肌)的T2和R2?值,取12个ROI的平均值.在造模后1个月的MRI扫描后随机处死腰痛组和正常组各6只大鼠,解剖获取实验鼠L4～L6水平双侧椎旁肌进行免疫荧光染色和Elisa实验,分别评价椎旁肌肌球蛋白重链和TNF-α的表达情况.剩余实验鼠在造模后3个月和6个月分别重复以上实验.结果:行为学评估结果显示,造模后6个月时腰痛组的步态评分高于正常组,且差异具有统计学意义(Z=-2.345,P=0.019);在造模后3和6个月时腰痛组的冷热刺激缩爪时间阈值显著降低、弯腰时间显著增加,与正常组之间的差异均具有统计学意义(P<0.05).T2-mapping和BOLD成像显示,与正常组相比,腰痛组造模后3和6个月时椎旁肌的T2值显著减小,造模后6个月时R2?值显著增大,且组间差异均具有统计学意义(P<0.05).免疫荧光染色结果显示,与正常组比较,腰痛组于造模后6个月时椎旁肌肌球重链蛋白1(MYH1)的表达水平增高(Z=-2.882,P=0.004),肌球重链蛋白7(MYH7)的表达水平减低(Z=-2.882,P=0.004).ELISA实验结果显示,腰痛组椎旁肌的TNF-α表达水平于造模后1个月高于正常组,且差异具有统计学意义(t=-10.279,P<0.001).结论:BOLD成像及T2-mapping成像技术能够无创性定量评估盘源性腰痛大鼠椎旁肌微结构的变化.

目的 分析增强CT和MRI轮辐征在鉴别诊断肝脏局灶性结节增生(FNH)和其他肝脏局灶性病变中的价值.方法 回顾性分析经病理证实的210例肝脏局灶性病变患者的增强CT及MRI图像,其中FNH 37例(40个病灶),其他肝脏局灶性病变173例(219个病灶).采用x2检验比较不同检查方式、增强期相FNH轮辐征的检出率,计算并比较轮辐征、供血动脉征诊断FNH的特异性、敏感性、准确性、阳性预测值、阴性预测值及曲线下面积(AUC).结果 增强CT的FNH轮辐征检出率(78.79％,26/33)明显高于增强MRI(34.38％,11/32)(P＜0.001),动脉早期的FNH轮辐征检出率(81.82％,27/33)明显高于动脉晚期(33.33％,10/30)(P＜0.001).轮辐征诊断FNH的敏感性、特异性、准确性、阳性预测值及阴性预测值分别为70.00％、94.98％、91.11％、71.79％和94.55％,AUC为0.85;供血动脉征诊断FNH的敏感性、特异性、准确性、阳性预测值及阴性预测值分别为67.50％、58.45％、59.85％、22.88％和90.78％,AUC为0.63.比较轮辐征和供血动脉征对FNH的诊断效能,轮辐征诊断FNH的特异性、准确性、阳性预测值及AUC均明显高于供血动脉征(P＜0.001).结论 增强CT和MRI轮辐征是FNH的特异影像学表现之一,有助于鉴别FNH和其他肝脏局灶性病变,建议在增强CT动脉早期的MIP上观察该征象.

Objective:To explore the value of iterative decomposition of water and fat with asymmetry and least squares estimation-quantitative fat imaging (IDEAL-IQ) in quantitative evaluation of thigh muscle fat content and its correlation with muscle strength in middle-aged and elderly volunteers.Methods:From December 2020 to April 2021, 30 volunteers aged 45 to 70 were recruited prospectively, including 15 males and 15 females with 52.5 (49.0, 56.3) years old. All subjects were scanned at 3.0 T MR, including axial T 1WI, IDEAL-IQ and coronal T 2WI of the left thigh. The region of interest of the knee extensors (quadriceps femoris) and knee flexors (hamstrings) in the left mid-thigh were delineated, and muscle cross-sectional area (CSA), skeletal muscle index (SMI), intermuscular fat fraction (FF) and intramuscular FF were obtained. In addition, isokinetic muscle strength measurement was performed on the left knee joint of all subjects at angular speeds of 60°/s and 180°/s to obtain peak torque (PT) and total work (TW) of knee flexors and extensors. Independent sample t-test, paired t-test or Mann-Whitney U test were used to compare the differences of CSA, SMI, intermuscular FF, intramuscular FF, PT and TW between different genders and muscle groups. Pearson or Spearman correlation analysis, and multiple linear regression analysis were used to analyze the correlation between CSA, SMI, intermuscular FF, intramuscular FF and PT, TW of thigh muscles. Results:The CSA, PT and TW of thighs in males were higher than those in females ( P<0.05), while the intermuscular FF in males was lower than that in females ( P=0.005). The CSA, SMI and PT of the thigh extensors were higher than those of the flexors ( P<0.001), while the intramuscular FF and intermuscular FF were lower than those of the flexors ( P<0.001). Intramuscular FF of flexors and extensors were moderately negatively correlated with PT ( r=-0.635, P<0.001; r=-0.546, P<0.001), and highly, moderately negatively correlated with TW ( r=-0.718, P<0.001; r=-0.616, P<0.001). Intermuscular FF of flexors and extensors were moderately negatively correlated with PT ( r=-0.519, P=0.003; r=-0.443, P=0.014), and negatively correlated with TW ( r=-0.363, P=0.049; r=-0.552, P=0.002). There was no significant correlation between CSA, SMI and PT, TW in flexors and extensors of thigh ( P>0.05). Multiple linear regression analysis showed that intramuscular FF was still significantly correlated with PT and TW of flexors and extensors (flexors: R 2adj=0.505, P=0.001; R 2adj=0.540, P<0.001; extensors: R 2adj=0.351, P=0.006; R 2adj=0.470, P=0.002). Conclusion:FF based on IDEAL-IQ technology can accurately quantify the intramuscular and intermuscular fat content of thighs, and there are negative correlations between intramuscular FF, intermuscular FF and isokinetic muscle strength measurements including PT and TW. Among them, intramuscular FF is more significant.

目的 探讨肝脏囊虫感染的影像学特征.方法 搜集8例患者临床及影像学资料,分析病灶分布、数量、大小、形态、密度/信号、强化方式及胆管扩张、脾大、淋巴结肿大、腹腔积液等影像学特点.结果 8例均为多发病灶,4例累及肝脏多叶,呈“簇样”不规则圆形/类圆形、结节状或蜂窝样表现,沿门静脉走行为主分布于肝脏深部或包膜下近肝表面,最大径约3.5～7.8 cm.CT平扫为多房囊样低密度,边界清或不清,2例见细点状“靶征”,增强扫描门静脉期呈“蜂窝样”强化;MR呈“多房状”/片状长/稍长T2、T1信号,2例见“靶征”,扩散加权成像(DWI)以高信号为主,3例见稍短T1信号,5例病灶外缘见短T2信号环(完整或不完整),2例肝包膜局部增厚、凹凸不平并强化,1例肝内胆管稍扩张,5例病灶呈“蜂窝样”强化,2例见“轨道征”,4例淋巴结肿大,1例脾稍大,2例少许腹腔积液.结论 肝脏囊虫感染少见,CT和MRI特征结合相关临床资料,有助于该疾病的诊疗.

目的 探索使用ImageJ在MRI T1WI图像上分割量化大腿皮下脂肪(subcutaneous adipose tissue,SAT)、肌内脂肪(intramuscular fat,IntraMF)及肌间脂肪(intermuscular fat,InterMF)的可行性.材料与方法 对28名志愿者(包括14名2型糖尿病患者)行大腿中部MRI扫描,在轴位T1图像上对肌肉脂肪浸润程度进行Goutallier分级;通过ImageJ分割测量大腿SAT、IntraMF及InterMF的面积;通过定量非对称回波的最小二乘估算法迭代水脂分离序列(iterative decomposition of water and fat with echo asymmetry and least squares estimation quantification sequence,IDEAL-IQ)测量的脂肪分数以计算大腿肌肉内的脂肪面积.分析ImageJ分割方法和Goutallier分级与IDEAL-IQ脂肪定量方法的相关性.检测ImageJ分割方法的观察者内和观察者间可靠性.结果 ImageJ分割方法和IDEAL-IQ脂肪定量之间有很强的相关性(r=0.998,P<0.001);ImageJ分割大腿SAT面积的观察者间及观察者内ICC均为0.999,P<0.001;大腿InterMF面积观察者间ICC为0.941,P=0.003,观察者内ICC为0.992,P<0.001;大腿IntraMF面积观察者间ICC为1.000,P<0.001,观察者内ICC为0.997,P<0.001.结论 ImageJ在MR T1序列上分割量化大腿SAT、IntraMF及InterMF具有良好的可靠性,且与IDEAL-IQ脂肪定量方法有很强的相关性.ImageJ分割是半定量Goutallier分级的一种可行替代方法.

Background At present, the most effective and mature treatment after ACL injury and tear is ACL reconstruction, but the rehabilitation process after ACL reconstruction that is very long, so it is very important to find early MRI positive findings of knee instability. Methods We retrospectively collected the clinical and imaging data of 70 patients who underwent ACL reconstruction from January 2016 to December 2019; Based on clinical criteria, the patients were divided into a stable group ( n = 57) and an unstable group ( n = 13); We measured the MRI imaging evaluation indexes, including the position of the bone tunnel, graft status, and the anatomical factors; Statistical methods were used to compare the differences of imaging evaluation indexes between the two groups; The prediction equation was constructed and ROC curve was used to compare the prediction efficiency of independent prediction factors and prediction equation. Results There were significant differences in the abnormal position of tibial tunnel entrance, percentage of the position of tibial tunnel entrance, position of tibial tunnel exit, lateral tibial posterior slope (LTPS), width of intercondylar notch between stable knee joint group and unstable knee joint group after ACL reconstruction ( P < 0.05); The position of tibial tunnel exits and the lateral tibial posterior slope (LTPS) and the sagittal obliquity of the graft were independent predictors among surgical factors and self-anatomical factors ( P < 0.05); The prediction equation of postoperative knee stability was established: Logit(P) = -1.067–0.231*position of tibial tunnel exit + 0.509*lateral tibial posterior slope (LTPS)-2.105*sagittal obliquity of the graft; The prediction equation predicted that the AUC of knee instability was 0.915, the sensitivity was 84.6%, and the specificity was 91.2%. Conclusions We found that abnormalities of the position of the exit of the bone tunnel, lateral tibial posterior slope (LTPS) and sagittal obliquity of the graft were the early MRI positive findings of knee instability after ACL reconstruction. It is helpful for clinicians to predict the stability of knee joint after ACL reconstruction.

患者 男,56岁.因体检发现右肝占位3 月余入院.既往30年前因车祸伤脾破裂行脾切除术.患者无明显临床症状,体格检查于左上腹部见一长约 10 cm手术瘢痕.实验室检查:乙肝表面抗体、乙肝 E抗体及乙肝核心抗体阳性;肿瘤标志物无异常.CT检查示:肝右后叶见一等密度结节(图 1 ),增强动脉期明显强化,门脉期持续强化(图 2),延迟期强化稍下降;脾脏未见显示,脾床区见明显强化结节.MRI 检查示:肝右后叶见一结节状稍长T2、T1 信号,边界清楚,DWI 呈高信号,增强动脉期斑片状轻度强化,门脉期与肝实质分界不清(图 3),延迟期病灶中心强化消退,边缘包膜样强化(图 4),肝胆期呈低信号;脾脏未见显示,脾床区结节状稍长 T2、T1 信号,增强呈不均匀强化,残余脾脏与副脾待鉴别.B 超示:肝右后叶探及一实性稍低回声结节.术后标本示:病灶位于肝右后叶,大小约2 cm×2 cm,质软,与周围肝组织分界清楚,切面呈红色(图 5).病理镜下示:病灶周围可见纤维包膜,HE染色可见淋巴滤泡形成的白髓及脾索、血窦构成的红髓(图 6 );免疫组化:CD3 (+)、CD20 (+)、CD68(+)、Ki-67(3％+);病理诊断:肝内异位脾组织.