MRI鉴别诊断表现为磨玻璃结节的早期浸润性肺腺癌

目的 探讨MRI鉴别诊断表现为磨玻璃结节的早期浸润性肺腺癌的价值。方法 回顾性分析34例表现为肺部磨玻璃结节的肺腺癌患者的MRI资料,根据病理结果将其分为非浸润性腺癌组（包括不典型腺瘤样增生、原位腺癌和微浸润性腺癌,n=15）和浸润性腺癌组（n=19）。测量并比较2组病变的最大径、T2WI信号强度和ADC值,绘制ROC曲线,评价其鉴别诊断浸润性腺癌的效能。结果 非浸润性腺癌组病变最大径小于浸润性腺癌组[（9.91±2.63）mm vs（13.12±2.71）mm,P<0.01]。非浸润性腺癌组病变T2WI信号强度低于浸润性腺癌组（92.97±8.33 vs 113.57±22.88,P<0.01）。非浸润性腺癌组病变ADC值低于浸润性腺癌组[（0.98±0.22）×10^-3 mm²/s vs（1.34±0.31）×10^-3 mm²/s,P=0.01]。ROC曲线分析结果显示,病变最大径诊断浸润性腺癌与非浸润性腺癌的AUC为0.791,临界值为11.52 mm,敏感度为73.72%,特异度为73.33%。结论 病变最大径、T2WI信号强度、ADC值对鉴别诊断表现为磨玻璃结节的浸润性与非浸润性肺腺癌具有一定价值。     

轻度狭窄与无狭窄颈动脉斑块高分辨率MRI特征

目的 探讨脑血管病患者轻度狭窄或无狭窄颈动脉粥样硬化（AS）斑块的高分辨率MRI（HRMRI）特征。方法 对103例近期出现脑血管病症状且伴颈动脉AS斑块的患者行颈动脉HRMRI。排除图像质量差或颈动脉严重狭窄（狭窄程度≥50%）者。对颈动脉斑块进行定性和定量分析,比较无狭窄（无狭窄组）与轻度狭窄（轻度狭窄组,狭窄程度1%～49%）颈动脉AS斑块的负荷及成分特征差异。结果 最终86例患者共155支颈动脉血管纳入研究,轻度狭窄组24支,无狭窄组131支。无狭窄与轻度狭窄组颈动脉管腔面积[（53.40±15.29）mm² vs （41.30±11.57）mm², P<0.001]和最大管壁厚度[（2.16±0.90）mm vs （3.30±1.25）mm, P=0.014]差异均有统计学意义,而管壁面积[（31.69±6.80）mm² vs （32.80±9.33）mm², P=0.581]差异无统计学意义。无狭窄组和轻度狭窄组存在中度风险斑块、高风险斑块者分别占10.69%（14/131）、6.11%（8/131）和20.83%（5/24）、20.83%（5/24）。颈动脉最大管壁厚度与管腔狭窄程度之间呈正相关（r=0.430,P<0.001）。结论 无狭窄或轻度狭窄的颈动脉血管仍存在发生不稳定斑块的风险。     

高分辨率MR管壁成像评估缺血性脑卒中患者血管斑块稳定性

目的 分析高分辨率MR管壁成像（HR-VWI）评估不同亚型缺血性脑卒中患者血管斑块稳定性的价值。方法 回顾性分析43例临床诊断缺血性脑卒中患者的MR HR-VWI资料,包括15例载体动脉（斑块或血栓）阻塞穿支（PAOPA）（PAOPA组）,22例动脉到动脉栓塞（ATAE）（ATAE组）,3例低灌注/栓子清除下降（HP/IEC）及3例混合机制（MM）。比较PAOPA组与ATAE组责任斑块形态、分布、位置及管腔表现的差异。结果 PAOPA组与ATAE组间责任斑块分布差异无统计学意义（χ²=12.16,P>0.05）。ATAE组责任斑块表面不规则发生率（63.64%）及斑块负荷[（70.39±11.27）%]均高于PAOPA组[26.67%,（63.11±10.57）%,χ²=8.87,t=4.02,P=0.04、0.03]。ATAE组斑块2级强化发生率（81.82%）高于PAOPA组（26.67%,χ²=7.51,P=0.03）,斑块0级强化发生率（9.09%）低于PAOPA组（46.67%,χ²=8.02,P=0.03）;2组斑块偏心性分布发生率、斑块内T1高信号发生率、斑块厚度、责任斑块处管腔狭窄率及血管重构方式差异均无统计学意义（P均>0.05）。结论 HR-VWI对鉴别不同亚型缺血性脑卒中血管斑块的稳定性具有一定价值;相比PAOPA,ATAE斑块HR-VWI更多表现出不稳定特征。     

3.0T高分辨率磁共振血管壁成像及伪连续式动脉自旋标记技术在单侧烟雾病中的应用

目的 探讨3.0T高分辨率磁共振(HR-MRI)血管壁成像及伪连续式动脉自旋标记(3D-pCASL)技术诊断及评估单侧烟雾病(MMD)的应用价值。方法 对经DSA确诊的17例单侧MMD患者行3D-TOF MRA、HR-MRI及3D-pCASL检查。分析单侧MMD患者大脑中动脉(MCA)狭窄段管壁外缘面积,狭窄类型(偏心或向心性),管壁信号强度(均匀或不均匀)及狭窄段周围血管,评估单侧MMD脑血流灌注情况。结果 单侧MMD患者受累侧MCA狭窄段管壁外缘面积为(2.17±0.39)mm²,镜像侧为(6.11±0.37)mm²,二者差异有统计学意义(t=31.52,P<0.001)。17例单侧MMD患者均表现为单一受累MCA管腔均匀缩小或闭塞,管壁信号强度一致,狭窄段周围出现2个以上流空血管影,累及同侧颈内动脉(ICA)末端。受累侧MCA供血区(额颞叶)CBF值为(24.76±10.86)ml/min/100 g,低于镜像侧的(59.84±9.72)ml/min/100 g,差异有统计学意义(t=7.89,P<0.001),受累侧枕叶CBF值为(47.59±7.26)ml/min/100 g,镜像侧为(48.30±9.06)ml/min/100 g,二者差异无统计学意义(t=0.70,P=0.49)。结论 单侧MMD患者的HR-MRI表现具有一定的特征性,可提示诊断。3D-pCASL技术能反映单侧MMD患者脑血流灌注的基本情况,可用于临床评估与长期随访。     

MR T2* mapping技术评估干燥综合征涎腺病变

目的 探讨MR T2^* mapping技术评估干燥综合征（SS）涎腺病变的价值。方法 前瞻性收集43例临床确诊的SS患者（SS组）和40名健康志愿者（对照组）,对双侧腮腺及颌下腺行含T2^* mapping的MR扫描,测量腺体T2^*值。基于T1WI、T2WI及MR涎腺导管成像对腮腺、颌下腺进行形态学诊断,对比SS组与对照组间腮腺、颌下腺T2^*值的差异。以Logistic回归联合ROC曲线评估MR形态学、T2^*值及二者联合对SS涎腺病变的诊断效能。比较不同诊断方式对同种病变诊断、同一诊断方式对不同病变诊断准确率的差异,分析T2^*值测量结果观察者内及观察者间的一致性。结果 SS组双侧腮腺平均T2^*值[（12.88±3.37）ms vs（10.18±1.88）ms,t=-6.40,P<0.01）及双侧颌下腺平均T2^*值[（23.58±3.73）ms vs（21.36±1.86）ms,t=-0.49,P<0.01）均明显高于对照组。MR形态学与T2^*值联合诊断SS腮腺及颌下腺病变的准确率均明显高于独立诊断（腮腺病变：Z=0.803、4.471,P均<0.01;颌下腺病变：Z=8.398、5.329,P均<0.01）,而单纯MR形态学与单纯T2^*值诊断的准确率差异均无统计学意义（腮腺病变：Z=1.388,P=0.165;颌下腺病变：Z=0.553,P=0.579）。在腮腺病变和颌下腺病变之间,单纯MR形态学（Z=2.525,P=0.05）、T2^*值（Z=0.677,P=0.498）及二者联合（Z=0.207,P=0.835）的诊断准确率差异均无统计学意义。观察者内及观察者间T2^*值测量的一致性均较好。结论 T2^* mapping技术测量T2^*值能够评估SS早期腮腺、颌下腺病变,与MR形态学联合应用可提高诊断准确率。     

MRI信号强度预测子宫肌瘤微波消融能量的可行性

目的 探讨根据MR T2WI信号强度预测微波消融子宫肌瘤所需能量的可行性。方法 于超声引导对143例子宫肌瘤患者(共197个病灶)行经皮微波消融治疗,对其中42例(49个病灶)于微波消融术前、术后进行盆腔平扫+MR增强扫描。微波消融功率为50 W,微波天线型号均为T11a。术前根据MR T2WI中子宫肌层信号强度为标准,将子宫肌瘤分为高、等、低信号3组;消融后测量增强MRI中无灌注区体积作为消融体积,对子宫肌瘤微波消融能效因子进行统计学分析。结果 低、等、高信号组子宫肌瘤微波消融平均能效因子分别为(685.01±206.27)J/cm³、(702.70±254.25)J/cm³和(945.12±321.83)J/cm³,高信号组与低信号组比较差异有统计学意义(P=0.015)。结论 根据MR T2WI中子宫肌瘤的信号强度可初步预测微波消融所需能量;微波消融中,T2WI呈高信号的子宫肌瘤所需能量高于呈低信号者。     

高分辨MRI观察复发脑梗死患者颅内动脉粥样硬化斑块及其危险因素

目的 以高分辨MRI（HR-MRI）观察初发脑梗死（PCI）与复发脑梗死（RCI）颅内动脉粥样硬化斑块特征，并分析RCI危险因素。方法 收集75例大脑中动脉或基底动脉狭窄并接受HR-MR检查的脑梗死患者，根据既往有无脑梗死病史分为PCI组（n=41）和RCI组（n=34），比较2组动脉粥样硬化斑块HR-MRI特征及临床资料，并分析脑RCI危险因素。结果 RCI组吸烟史占比、同型半胱氨酸（HCY）及尿酸（UA）水平高于PCI组（P均<0.05），组间其余临床资料及实验室结果差异无统计学意义（P均>0.05）。HR-MRI示RCI组责任血管重度狭窄占比及斑块负荷高于PCI组，斑块较易出现T2WI、T1WI高信号，且强化程度高（P均<0.05）。Logistic回归分析结果显示斑块T2WI高信号、管腔重度狭窄、高HCY及高UA均为RCI的危险因素（P均<0.05）。结论 RCI的HR-MRI表现具有一定特征性，斑块呈T2WI高信号及管腔重度狭窄为脑梗死复发危险因素；联合临床相关危险因素有助于对患者进行分层管理。     

磁共振R2* mapping评估大鼠急性放射性肝损伤模型早期肝纤维化

目的 探讨MR R2^* mapping技术评估SD大鼠急性放射性肝损伤模型早期肝纤维化的可行性。方法 将30只SD大鼠随机平均分为3组,以固定剂量对大鼠右半肝进行单次放疗,制备急性放射性肝损伤大鼠模型。于放疗前、放疗后1个月（A组）、2个月（B组）和3个月（C组）,分别行T1WI、T2WI及R2^*扫描。扫描后处死大鼠行病理学检查、评估肝纤维化分期。测定大鼠左、右半肝的T1WI和T2WI的信号强度及R2^*值,分析R2^*值与大鼠肝纤维化病理分期的相关性。结果 最终7只大鼠死亡,A组8只、B组8只、C组7只纳入研究。A、B、C组大鼠肝左叶及右叶相对T1、T2值差异无统计学意义（P均>0.05）。放疗后3组肝右叶R2^*值均高于肝左叶（P均<0.05）。3组组间两两比较,肝右叶R2^*值随放疗后时间延长而升高（P均<0.05）,肝左叶的R2^*值差异均无统计学意义（P均>0.05）。放疗前大鼠肝右叶R2^*值为（38.42±5.69）Hz,S0期大鼠肝右叶R2^*值为（50.75±6.12）Hz,S1期为（58.73±6.40）Hz,S2期（64.34±5.87）Hz。肝右叶R2^*值与病理分期呈高度正相关（r_s=0.819,P<0.05）。结论 R2^*值可用于准确反映SD大鼠急性放射性肝损伤模型早期纤维化程度。     

三维多普勒血流频谱定量技术评估2型糖尿病患者拇指动脉血流

目的 应用三维多普勒频谱定量分析技术检测2型糖尿病(T2DM)患者拇指动脉血流,评估T2DM患者外周微小动脉血流的特点。方法 本研究根据T2DM的病程,将所有患者分为T2DM组1(病程≤5年;n=47)与组2(病程>5年;n=45)两组,46例正常志愿者为对照组。应用三维多普勒频谱定量分析技术的流速-血管深度频谱图模式,测定拇指动脉内径及拇指动脉频谱图收缩期瞬时最大血流面积(A_flow)。并且测定收缩期最大血流速度(PSV)、舒张末期血流速度(EDV)、阻力指数(RI)。结果 所有T2DM患者拇指动脉血管内径均较对照组缩小[正常人拇指动脉血管内径平均为(2.11± 0.19)mm,T2DM组1平均为(1.71±0.21)mm,T2DM组2平均为(1.59± 0.25)mm,P<0.001];T2DM两组患者的拇指动脉A_flow较对照组显著减低[T2DM组1平均为(61.35±10.66)mm²/s,T2DM组2平均为(46.50±6.59)mm²/s,对照组平均为(75.32±11.97)mm²/s,P<0.001]。而且T2DM组2的拇指动脉A_flow较T2DM组1更为减低(P<0.001)。结论 三维多普勒超声技术所测拇指动脉内径与相关血流参数,可应用于临床观测T2DM患者外周微小血管的损伤度,为观测糖尿病患者外周血管病变提供一种可靠的无创伤性分析手段。     

颅内管腔非狭窄性脑卒中患者动脉粥样硬化斑块特点

目的 以高分辨率MRI（HRMRI）观察颅内管腔非狭窄性脑卒中患者动脉粥样硬化斑块的特点。方法 纳入41例MR血管造影（MRA）未见明显异常的动脉粥样硬化性缺血性脑卒中患者,根据HRMRI所见分析其颅内动脉粥样斑块,比较责任斑块与非责任斑块位置、强化、血管重构及斑块负荷的差异。结果 41例中,于33例（33/41,80.49%）中检出50个颅内斑块,平均负荷值（12.96±8.03）%;斑块所在血管正性重构率72.00%（36/50）。8例（8/41,19.51%）未见明确斑块。50个斑块中,17个为责任斑块,33个为非责任斑块,责任斑块位于前循环的比例明显高于非责任斑块（P<0.05）,其强化状态、负荷及血管重构差异均无明显统计学意义（P均>0.05）。结论 颅内管腔非狭窄性脑卒中患者斑块负荷较低,且斑块所在血管易发生正性重构,前循环斑块更多导致脑血管病事件。     

复发急性缺血性脑卒中患者大脑中动脉斑块的高分辨率MRI研究

目的利用3.0 T高分辨磁共振(HR-MRI)研究复发急性缺血性脑卒中患者大脑中动脉斑块形态特征。材料与方法回顾性分析77例责任血管为大脑中动脉的急性缺血性脑卒中患者资料,其中初发患者36例(初发组),复发患者41例(复发组),所有患者均行3.0 T高分辨磁共振斑块成像(扫描序列包括TOF-MRA,头颅常规DWI,责任血管轴位T1WI、T2WI及T1WIGd-DTPA增强)。对比分析初发组与复发组急性缺血性脑卒中患者责任血管管腔狭窄率、最小管腔面积、斑块负荷、斑块强化率、T1WI及T2WI斑块信号强度指数。结果复发组患者大脑中动脉管腔狭窄率(P=0.002)、斑块负荷(P=0.005)、斑块强化率(P=0.037)均明显高于初发组,最小管腔面积(P=0.001)明显小于初发组。复发组斑块T2WI信号强度指数大于初发组(P0.001),而T1WI信号强度指数两者无明显差异(P=0.245)。结论高分辨率磁共振可以有效评估复发急性缺血性脑卒中患者大脑中动脉斑块的形态特征,综合评价斑块特征可为临床提供参考以助于预防脑卒中复发。     

症状性颅内动脉粥样硬化斑块易损性的直方图纹理分析

目的本研究通过比较颅内动脉粥样硬化斑块的形态学及直方图纹理特征的差异,进一步分析症状性斑块的特征。材料与方法 2016年1月至2017年1月对可疑脑卒中患者及部分体检者进行颅内动脉管壁HR-MRI。用CMRTools及Image J 14.0软件测量各个序列上病变最狭窄处斑块的特征值。采用Logistic回归模型进行统计学分析。结果 133例受试者[平均年龄(58.5±11.4)岁]中急性缺血性卒中患者75例,无症状者58例。在T2WI及T1WI增强序列中直方图的特征值无统计学差异。Logistic回归分析发现斑块的最小管腔面积(minimal luminal area,MLA。OR=1.301;95%CI,1.036~1.633)、斑块内出血(intraplaque hemorrhage,IPH。OR=12.440;95%CI,1.551~99.780)和变异系数(coefficient of variation,CV。OR=3.476;95%CI,1.513~7.985)是脑血管事件发生的危险因素。ROC曲线显示三个特征结合起来共同评判斑块易损性时,其曲线下面积可达0.801。结论在非增强的T1WI上定量直方图纹理分析法可以用来鉴别急性症状性颅内动脉粥样硬化斑块与无症状性斑块,而且直方图分析法较之前的形态学分析法对斑块易损性的判别有更高的价值。     

Differences of signal evolution of intraplaque hemorrhage and associated stenosis between symptomatic and asymptomatic atherosclerotic carotid arteries: an in vivo high-resolution magnetic resonance imaging follow-up study

To evaluate the differences of signal evolution of intraplaque hemorrhage (IPH) and associated stenosis between symptomatic and asymptomatic atherosclerotic carotid arteries. Thirty-three carotid arteries (15 symptomatic and 18 asymptomatic plaques) with recent carotid IPH underwent serial high-resolution MRI examinations on a 3.0-Tesla (3.0T) MRI scanner over a period of 18 months. MR sequences included three-dimensional time-of-flight (3D-TOF), quadruple-inversion-recovery T1-weighted imaging (QIR T1 WI), proton density-weighted imaging (PDWI), and T2-weighted imaging (T2WI). The contrast-to-noise ratios (CNRs) of subsequent IPH during the follow-up period between symptomatic and asymptomatic carotid IPH showed a significant difference on 3D-TOF (P = 0.029), T1 WI (P = 0.005), and PDWI (P = 0.028), except for that on T2WI (P = 0.362). Compared with no significant signal intensity change of symptomatic IPH, CNRs of asymptomatic IPH exhibited a gradually descending trend on all contrast weighted images (P < 0.05). Compared with asymptomatic arteries, the degree of diameter stenosis associated with IPH increased significantly in the symptomatic atherosclerotic carotid arteries between baseline and the 18th month (10.53 ± 12.29% vs. 1.65 ± 7.74%, P = 0.017). Symptomatic and asymptomatic carotid IPH demonstrated different MRI signal evolution and associated carotid stenosis. Repeated carotid IPH may be more common in symptomatic plaques than in asymptomatic plaques and might produce a stronger stimulus for progression of atherosclerosis than one-time carotid IPH.     

Three-dimensional volumetric analysis of atherosclerotic plaques: a magnetic resonance imaging-based study of patients with moderate stenosis carotid artery disease

Atherosclerotic plaque burden has a strong correlation with plaque vulnerability. Three-dimensional (3D) volumetric assessment of atherosclerotic plaques has been suggested as an accurate method of quantifying plaque burden but has not been performed. In this study we use high-resolution magnetic resonance (MR) imaging to compare 3D volume differences of asymptomatic and acutely symptomatic carotid plaques (i.e. had cerebrovascular ischaemic symptoms within the previous 72 h of MR imaging). One hundred patients (46 acutely symptomatic and 54 asymptomatic) with atherosclerotic carotid artery disease underwent carotid MR imaging. Manual segmentation of plaque components was done to delineate lipid, fibrous tissue and plaque haemorrhage (PH). 3D-volume reconstruction of plaque components was done and used for comparison. Acutely symptomatic plaques had a lower normalized wall index and normalized volume index than the asymptomatic group (P = 0.04 and 0.01 respectively). Median percentage lipid volume was higher for asymptomatic plaques (28 vs. 5%, P = 0.004). However, the median percentage volume and prevalence of PH was higher in the acutely symptomatic group (P = 0.01 and 0.02 respectively). Acutely symptomatic plaques have less lipid content immediately after the acute event than asymptomatic plaques. This is most likely because of the escape of lipid-rich atheromatous debris into the blood stream at the time of plaque rupture. Due to this paradox, “high” lipid content of a plaque may not be a reliable feature of estimating its vulnerability immediately following the acute event. PH, which is prevalent and consistent in such plaques, may be a better indicator of plaque vulnerability during that period.     

离体冠状动脉粥样硬化钙化斑块CT、MRI及病理对照

目的 评价64层CT和1.5T MR扫描仪在显示离体冠状动脉粥样硬化钙化斑块成分的作用.方法 对12具尸体心脏行冠状动脉前降支近段CT及MR检查,并与病理学相对照.分析钙化斑块的CT值及MRI的信号强度.结果 43个CT、MRI所示的钙化斑块层面可与相应的组织学层面相对应.钙化成分为主的斑块CT值平均为1065 HU.MRI示钙化斑块在各个序列均表现为低信号,48.84%的钙化层面内有稍高信号,组织切片示脂质成分.58.14%的钙化斑块内有新生血管或炎细胞浸润.结论 CT、MRI都可以显示冠状动脉粥样硬化钙化斑块的特点,但显示钙化斑块内的脂质成分,MRI优于CT.     

基于MRI影像组学预测宫颈癌淋巴血管间隙浸润

目的 评估基于MRI影像组学模型术前预测宫颈癌淋巴血管间隙浸润(LVSI)的价值.方法 回顾性分析123例经病理证实宫颈癌患者,根据病理结果分为LVSI+(n=61)及LVSI-(n=62).基于T2WI及动脉期对比增强T1WI(CE-T1WI)提取影像组学特征,按7:3比例将数据分为训练集(n=87)和验证集(n=3...     

Characterization of culprit lesions in acute coronary syndromes compared with stable angina pectoris by dual-source computed tomography

To identify the characterization of culprit lesions in acute coronary syndrome (ACS) compared with stable angina pectoris (SAP) by dual-source computed tomography (DSCT). 65 patients with ACS and 75 controls with SAP and a similar atherosclerotic risk profile were studied. Computed tomography (CT) coronary angiography was performed using a DSCT scanner before invasive catheterization. Using DSCT and quantitative coronary angiography (QCA), lesion characteristics [luminal cross-section area (L-CSA), vascular cross-section area (V-CSA), plaque area and degree of stenosis) were detected. Plaque types, mean and minimum CT density (Hounsfield Unit; HU), remodeling index, and presence of “spotty” calcifications were analyzed using DSCT. A good correlation was observed between DSCT and QCA for all lesion characteristics (P < 0.05). Culprit lesions in ACS had much larger V-CSA (20.5 ± 6.0 vs. 14.8 ± 4.8 mm²), plaque area (15.3 ± 5.0 vs. 11.1 ± 3.3 mm²) and remodeling index (1.3 ± 0.2 vs. 1.0 ± 0.4) than stable lesions in SAP (P < 0.05). The prevalence of non-calcified/calcified/mixed plaque was 30/0/35 in ACS versus 25/15/35 stable lesions in SAP (P < 0.01). The proportion of “spotty” calcified plaques was 21.5 % in culprit lesions (14 of 65) versus 1.3 % in SAP (1 of 75). The mean/minimum HU of culprit lesions was 88.6 ± 43.2/154.2 ± 98.7 in ACS versus 45.9 ± 34.7/98.2 ± 76.8 in SAP (both P < 0.01). DSCT is a feasible means of detecting coronary stenosis with good accuracy compared with QCA. Culprit lesions in ACS display a greater proportion of non-calcified material with lower CT attenuation, “spotty” calcifications and higher remodeling index compared with SAP lesions.