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.     

高分辨率MRI脂肪抑制T2加权成像联合扩散加权成像在肛瘘及其活动性中的应用价值

目的:探讨高分辨率磁共振成像(MRI)脂肪抑制T2加权成像(压脂T2WI)联合扩散加权成像(DWI)在肛瘘(AF)及其活动性中的应用价值.方法:选择2019年1月～2021年1月本院收治的34例AF患者,所有患者在术前一周内行磁共振扫描,收集所有患者的临床资料及影像学资料进行分析.根据手术及病理结果分为活动性(PIA)...     

全身动脉血管磁共振血管成像对多发性大动脉炎的诊断价值

目的：探讨全身动脉血管增强磁共振血管成像（MRA）在多发性大动脉炎临床诊断中的应用价值。方法：对临床拟诊断为多发性大动脉炎的27例患者进行全身动脉血管MRA检查,在病变处再行SE序列T1加权像（T1 WI）、T2加权像（T2 WI）加脂肪抑制技术横断位或冠状位平扫,以显示受累血管的部位、范围及程度。结果：27例全身动脉血管MRA成像共显示血管狭窄、闭塞74段,假性动脉瘤5个,其中头臂动脉型12例,胸、腹主动脉型7例,广泛型8例。在T1 WI横断位或冠状位均可见到受累动脉的血管壁有不同程度增厚、有或无强化,管腔闭塞或向心性狭窄,部分病例伴狭窄后扩张。T2 WI扫描则清晰显示大多数的受累血管壁表现为多环状影,纤维化或者钙化的血管中膜,其中有一部分血管处于外层的环形低信号影比较厚,有一部分厚薄表现不均匀。最外层的受累血管壁则显示为环状高信号影,外膜显著增厚。结论：全身动脉增强MRA有助于显示多发性大动脉炎累及血管的部位、范围及程度,可以作为该病首选的检查方法。     

屏气磁共振胆胰管成像的扫描技术探讨

目的　规范化屏气磁共振胆胰管成像 (MRCP)扫描方案。方法　 81个病例接受SS FSE序列MRCP扫描 ,结果进行盲法比较。结果　厚层投射MRCP对胆胰管的显示优于MIP法 ;MIP法 2D原始图像对小结石的显示率高于厚层投射MRCP及MIP重建MRCP ;无脂肪抑制 2D原始图像对腔外肿块的显示优于脂肪抑制 2D图像 ;斜冠状面MRCP能更好显示肝门区胆管及壶腹部。结论　MRCP应采用斜冠状面扫描 ;2D原始图像对腔内小病变及腔外肿块的显示非常重要 ;完整的MRCP应结合多种技术     

多b值DWI联合T2WI在前列腺疾病良恶性鉴别中的应用价值

目的 探讨多b值弥散加权成像(DWI)联合T2加权成像(T2WI)在前列腺疾病良恶性鉴别中的应用价值.方法 选取2017年3月至2021年2月收治的60例前列腺特异抗原(PSA)升高的患者作为研究对象,行多b值(600、1000、1500、2000 s/mm2)DWI及T2WI,随后在经直肠超声引导下行12针的前列腺饱...     

磁共振T2加权成像联合弥散加权成像对前列腺癌包膜外扩散的预测价值

目的回顾性评估磁共振T2加权成像(T2WI)联合弥散加权成像(DWI)对前列腺癌(PCa)包膜外扩散(ECE)的预测价值。 方法60例术前行3.0T磁共振检查的PCa患者,依据影像资料和病理组织学检查结果,将患者分为ECE组和无ECE组。由2名影像学诊断医师对磁共振T2WI和T2WI联合DWI图像进行分析,评估PCa的ECE情况,并测量ECE组和无ECE组表观弥散系数(ADC)值,比较PCa ECE组和无ECE组的ADC值差异性。本研究经泰安市中心医院医学伦理委员会审核通过。 结果磁共振T2WI和T2WI联合DWI的敏感度与特异度分别为76.1%、84.3%。ROC分析显示,磁共振T2WI联合DWI曲线下面积明显大于磁共振T2WI曲线下面积(Az＝0.892,0.803,Z＝4.661,P<0.01)。ECE组ADC值[(0.72±0.14)×10^－3mm²/s]明显低于无ECE组[(0.94±0.21)×10^－3mm²/s](t＝3.82,P<0.01)。 结论磁共振T2WI联合DWI图像能够提高预测PCa患者ECE情况,ADC值对评估有无ECE具有重要参考价值。     

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。     

正常臂丛节后神经MR神经成像术

目的探讨正常人臂丛节后神经MR神经成像术参数及其可行性.方法对30例健康志愿者行双侧臂丛节后神经MR冠状位扫描,扫描序列包括:常规自旋回波序列(SE)T1加权(T1WI)、T2加权(T2WI,TSE)、MR神经成像术(MRN),观察3种序列对臂丛节后神经的同层显示情况,并计算各序列图像对比噪声比.结果 T1WI、 T2WI、MRN对臂丛节后神经同层显示率分别为56.7%、53.3%、83.3%;对臂丛节后神经根与锁骨下束同层显示率分别为50%、46.7%、70%.MRN对臂丛节后神经的同层显示率,臂丛节后神经根与锁骨下束同层显示率明显高于常规序列(P<0.01,P<0.05),T1WI与T2WI序列对臂丛节后神经的显示率无明显差异(P>0.05).各序列图像对比噪声比分别为:2.04±0.97、2.11±1.01、23.68±5.93,MRN图像对比噪声比明显高于常规组(P＝0.000).结论 MR神经成像术对臂丛节后神经的显示率及对比噪声比明显高于常规成像序列,使臂丛节后神经显示成为高信号,可作为显示臂丛病变的常规方法.     

儿童小肠MR成像临床应用评价

目的分析儿童小肠病变MRI表现,评价小肠MR成像在儿科中的临床应用价值。方法对12例经手术和病理证实的小肠病变患儿进行回顾性分析,检查前让患儿口服2.5%的等渗甘露醇溶液后,静脉注射山莨菪碱0.3mg/kg,随后行MR扫描,扫描方法包括冠状面真稳态进动快速成像(TrueFisp)序列,横断面及冠状面T1WI、T2WI脂肪抑制序列、vibe超薄容积扫描(压脂)序列,然后行带脂肪饱和技术的T1WI横断面及冠状面增强扫描。结果 12例患儿均能接受等渗甘露醇溶液,未发现并发症,其中Crohn病6例,共显示16段炎症肠管,MRI表现为增强后病变肠壁强化明显,病变肠段肠壁增厚(厚度为5～14mm),且多表现环形增厚,肠壁厚薄不均,肠腔变窄。十二指肠球部慢性溃疡、十二指肠球部穿孔、胃肠吻合口溃疡、小肠梗阻(柿石症)、小肠淋巴瘤、肠套叠各1例。小肠MR成像不仅显示了病变本身,还显示了肠壁、肠外血管及肠系膜脂肪的情况。结论小肠MR成像安全、有效、无创、无电离辐射,能全方位多维显示儿童小肠疾病的方法。     

基于T2加权成像及弥散加权成像的图像纹理分析预测宫颈鳞状细胞癌放化疗疗效的临床价值

目的 探讨MRI检查T2加权成像(T2-weighted imaging,T2WI)及弥散加权成像(diffusion-weighted imaging,DWI)图像纹理参数与宫颈鳞状细胞癌放化疗疗效的相关性.方法 回顾性纳入2015年2月至2016年1月北京协和医院接受放化疗的宫颈鳞状细胞癌患者,并根据其预后分为疾病...     

实验兔皮内、皮下注射钆双胺行间质MR淋巴管成像对脊柱旁淋巴干显像的对比分析

目的 探讨经兔足背皮内、皮下注射钆双胺行脊柱旁淋巴干MR成像的可行性。方法 选取新西兰大白兔8只,首先经足背皮内注射钆双铵（皮内组）,间隔3天后再经皮下注射（皮下组）,采集冠状位三维扰相梯度回波序列（fl3d-cor）图像,分别评价腰淋巴干及胸导管的显示情况。结果 皮内组显示所有兔两侧腘窝淋巴结、髂淋巴结及主动脉下淋巴结明显强化,强化持续时间大于30 min,最长达90 min;6例腰淋巴干全程及乳糜池明显强化;5例可见部分胸导管强化。皮下组显示所有兔两侧腘窝淋巴结均明显强化,但腰淋巴结、腰淋巴干及胸导管未见强化。腰淋巴干及胸导管强化程度总评分皮内组与皮下组差异有统计学意义（t=100.00,P=0.0002）。结论 足背皮内注射钆双胺淋巴管成像能较皮下注射更好地显示腰干淋巴管。     

Myocardial area at risk and salvage measured by T2-weighted cardiovascular magnetic resonance: Reproducibility and comparison of two T2-weighted protocols

Background

Late Gadolinium Enhancement (LGE) and T2-weighted cardiovascular magnetic resonance (CMR) provides a means to measure myocardial area at risk (AAR) and salvage. Several T2-weighted CMR sequences are in use, but there is no consensus in terms of which sequence to be the preferred. Therefore, the aim of the present study was to: (1) Assess the reproducibility and (2) compare the two most frequently used T2-weighted CMR protocols for measuring AAR and salvage.

Methods

91 patients with ST-elevation myocardial infarction treated with primary percutaneous coronary intervention underwent a CMR scan 1-7 days after initial treatment. Two different T2-weighted protocols, varying in slice thickness and echo time (TE), were applied covering the entire left ventricle (LV) (protocol 1: TE 65 msec and slice thickness 15 mm; protocol 2: TE 100 msec and slice thickness of 8 mm). On a second scan performed 3 months later, infarct size was assessed with a standard LGE sequence. The two protocols were compared in terms of AAR and salvage index. Furthermore, intra- and interobserver reproducibility were assessed.

Results

Protocol 1 measures a larger AAR and salvage index than protocol 2 with a mean difference in AAR of 1 ± 8%LV (p < 0.01) and 6 ± 12 g (p < 0.01) and salvage index of 0.04 ± 0.12 (p < 0.01). Both protocols had a high intra- and interobserver reproducibility with acceptable limits of agreement (6-8%LV and 6-12 g in AAR and 0.06-0.08 in salvage index).

Conclusions

We report acceptable reproducibility for AAR and salvage index measured by T2-weighted images. Thus CMR is a reliable tool for measuring AAR and salvage index. Protocol 2 (8 mm slice thickness and 100 msec TE) measures slightly smaller AAR than protocol 1 (15 mm slice thickness and 65 msec TE), but the present study does not allow for a clear recommendation of either of the protocols.     

T2-weighted MR imaging for hepatic hemangiomas: comparison of breath-hold and non-breath-hold turbo spin-echo pulse sequences with phased-array multicoil

Background: We compared T2-weighted and heavily T2-weighted breath-hold turbo spin-echo (TSE) sequences with T2-weighted non-breath-hold TSE sequence to evaluate hepatic hemangiomas on magnetic resonance (MR) with a phased-array multicoil. Methods: Twenty-two patients with 27 hemangiomas were studied at 1.0-T scanner by using T2-weighted and heavily T2-weighted breath-hold TSE sequences (18 s each) and non-breath-hold T2-weighted TSE sequences with use of a phased-array multicoil. Images were quantitatively analyzed for tumor-to-liver signal-difference-to-noise ratios (SD/Ns) and tumor-to-liver signal intensity ratios (T/Ls) and qualitatively analyzed for tumor conspicuity and motion-induced image artifacts. Results: Quantitatively, T2-weighted breath-hold TSE images showed the highest SD/Ns among the three sequences, although the differences from the heavily T2-weighted breath-hold TSE sequence and the T2-weighted non-breath-hold TSE sequence were not statistically significant (p= 0.61 and 0.06, respectively). Heavily T2-weighted breath-hold TSE images showed the highest T/Ls among the three sequences. The differences from the T2-weighted breath-hold TSE sequence and the T2-weighted non-breath-hold TSE sequence were statistically significant (p < 0.001). Qualitatively, breath-hold TSE images were superior to non-breath-hold TSE images in terms of tumor conspicuity (p < 0.01) and motion artifacts (p < 0.01). Conclusion: T2-weighted breath-hold TSE sequence is superior to T2-weighted non-breath-hold TSE sequence in the evaluation of hepatic hemangiomas on MR with a phased-array multicoil. Received: 7 April 1997/Accepted: 28 May 1997     

Evaluation of Crohn disease activity with magnetic resonance imaging

Background: The purpose of this study was to assess the accuracy of magnetic resonance imaging (MRI) in evaluating Crohn disease (CD) activity. The intestinal inflammatory activity is usually present in patients under pharmacologic treatment, despite their clinical remission. Methods: Twenty patients with CD, all under pharmacologic treatment, were prospectively studied by MRI at 1.5 T as a periodic control. Positivity of three acute-phase reactants was considered an index of biologic activity (BA). T2-weighted, T2-weighted fat-suppressed turbo spin-echo, and breath-hold T1-weighted turbo field-echo sequences, before and after gadolinium intravenous injection, were obtained. A negative superparamagnetic contrast agent was orally administered. The following MRI parameters were qualitatively evaluated by three radiologists at the level of the affected bowel and compared with clinical data: wall thickness (WT), wall T2-weighted signal (T2W), wall contrast enhancement (WE), amount of fibrofatty proliferation (FP), and T2-weighted signal of fibrofatty proliferation on fat-suppressed images (T2FP). The κ coefficient of agreement was calculated. The Spearman rank correlation was used for the analysis of clinical and radiologic data. Results: Nineteen of 20 patients were in clinical remission (Crohn Disease Activity Index < 150). On the basis of laboratory tests, nine of 20 patients had biologically active disease. An excellent correlation was found between BA and WE, T2W, and T2FP (0.900, 0.927 and 0.961, respectively; p < 0.0001), and a lower correlation was found between BA and WT and between BA and FP (0.78 and 0.62). Excellent statistical correlation was also found between WE and T2W and between WE and T2FP (0.876 and 0.892). Conclusions: An excellent statistical correlation was found between biologically “active” disease and the following MRI parameters: wall gadolinium enhancement, wall hyperintensity on T2-weighted fat-suppressed images, and hyperintensity of fibrofatty proliferation on T2-weighted fat-suppressed images. Therefore, MRI can be valuable in assessing CD activity. Received: 22 January 1999/Revision accepted: 3 November 1999     

腰椎间盘髓核退变的MRI研究(英文)

Objective The purpose of this study was to correlate T2 signal intensity values in nucleus pulposus of lumbar discs with patient age,gender and stage of nucleus pulposus degeneration.Methods Lumbar imaging findings of 422 cases subjects were retrospectively reviewed through T2 signal intensity values of nucleus pulposus evaluated based on the signal intensity values of MR T2-weighted mid-sagittal images of the lumbar spine,the t2 signal intensity values at all five lumbar levels (from L5-S1 to L1-L2) between male and female were used independent sample t-test and the Spearman correlation analysis.The age and grade of nucleus pulposus of disc degeneration and T2 signal intensity values were estimated by calculating and Chi-square test and the Spearman correlation analysis.The t-test was used to correlate the different anatomic levels of disc degeneration;T2 signal intensity values among the five different anatomic levels using non-parametric correlation analysis.Results There were significantly differences in T2 signal intensity values of nucleus pulposus at the same grade and anatomic level between male and female.Advanced with age,T2 signal intensity values of nucleus pulposus decreased and stage of disc degeneration increased accordingly.T2 signal intensity values may represent the nucleus pulposus degeneration of interverterbral disc.L4-L5 was the highest incidence among the nucleus pulposus degeneration of intervertebral disc.Conclusions The T2 signal intensity values based approach may be a feasible and practical tool to determine nucleus pulposus degeneration.T2 signal intensity values of nucleus pulposus of lumbar intervertebral disc are correlated with grade of degeneration and patient age.     

磁敏感加权成像对脑内毛细血管扩张症的诊断价值

目的分析SWI对脑内毛细血管扩张症的诊断价值。方法对搜集的5例经临床证实的脑内毛细血管扩张症行常规TSE-IR-T1WI、SE-T2WI及SWI,并对结果进行对比分析。结果5例均为多发病灶,共50灶,呈圆形或类圆形,直径约2mm-1cm。其中桥脑35灶,小脑10灶,基底节区5灶。T1WI等信号20灶,低信号30灶;T2WI等信号16灶,低信号34灶;50灶于SWI均呈低信号,其中39灶呈＂靶征＂。结论毛细血管扩张症在SWI上磁敏感性增强,有特征性表现,SWI对其检出优于常规MRI技术。     

Prolonged acute migraine with aura and reversible brain MRI abnormalities after liquid sclerotherapy

Transient visual disturbances constitute the most commonly reported neurological side effect during and immediately after sclerotherapy. A few studies, based on clinical and diffusion-weighted MRI assessments, have suggested that these transient neurological symptoms correspond to migraine with aura. Recently, it has been reported that brain magnetic resonance imaging can reveal transient T2*-weighted abnormalities during the acute phase of migraine with aura. We reported a 36-year-old man who presented with transient neurological symptoms and concomitant T2*-weighted abnormalities on brain magnetic resonance imaging immediately after liquid sclerotherapy. We hypothesize that the reversible nature of the patient’s T2*-weighted abnormalities may indicate a relationship with the post-sclerotherapy migraine with aura attack.     

T2 mapping定量分析健康青年人肩关节软骨T2值

目的 探讨T2 mapping成像评价青年健康志愿者肩关节软骨构成成分的可行性,并定量分析肩关节软骨T2值。方法 对16名青年健康志愿者行双侧肩关节斜冠状位8回波T2 mapping成像,并经后处理获得伪彩图,将肩关节软骨三等分为外带、中带、内带,测量其T2值。比较外带、中带、内带间T2值的差异及不同性别间、左右侧间T2值差异。结果 肩关节软骨外带、中带、内带T2值分别为（38.67±2.82）ms、（38.41±2.52）ms、（36.49±1.80）ms,总体差异有统计学意义（F=7.789,P=0.001）,肩关节外带、中带软骨T2值均大于内带（P均<0.05）。肩关节软骨外带、中带及内带的左侧与右侧T2值、不同性别间肩关节软骨外带、内带T2值差异均无统计学意义（P均>0.05）。不同性别间肩关节软骨中带T2值差异有统计学意义（P<0.05）。结论 T2 mapping成像可用于评价肩关节软骨构成成分变化。     

T2 relaxation time of hyaline cartilage in presence of different gadolinium‐based contrast agents

The transverse relaxation time, T₂, of native cartilage is used to quantify cartilage degradation. T₂ is frequently measured after contrast administration, assuming that the impact of gadolinium‐based contrast agents on cartilage T₂ is negligible. To verify this assumption the depth‐dependent variation of T₂ in the presence of gadopentetate dimeglumine, gadobenate dimeglumine and gadoteridol was investigated. Furthermore, the r₂/r₁ relaxivity ratios were quantified in different cartilage layers to demonstrate differences between T₂ and T₁ relaxation effects. Transverse high‐spatial‐resolution T₁‐ and T₂‐maps were simultaneously acquired on a 1.5 T MR scanner before and after contrast administration in nine bovine patellae using a turbo‐mixed sequence. The r₂/r₁ ratios were calculated for each contrast agent in cartilage. Profiles of T₁, T₂ and r₂/r₁ across cartilage thickness were generated in the absence and presence of contrast agent. The mean values in different cartilage layers were compared for global variance using the Kruskal–Wallis test and pairwise using the Mann–Whitney U‐test. T₂ of unenhanced cartilage was 98 ± 5 ms at 1 mm and 65 ± 4 ms at 3 mm depth. Eleven hours after contrast administration significant differences (p < 0.001) were measurable for all three contrast agents. T₂ values were 58 ± 2 and 62 ± 3 ms for gadopentetate dimeglumine, 46 ± 2 and 57 ± 2 ms for gadobenate dimeglumine, and 38 ± 2 and 42 ± 2 ms for gadoteridol at 1 and 3 mm depths, respectively. The r₂/r₁ relaxivity ratios across cartilage thickness were close to 1.0 (range 0.9–1.3). At 1.5 T, T₂ decreased significantly in the presence of contrast agents, more pronounced in superficial than in deep cartilage. The change in T₂ relaxation rate was similar to the change in T₁. Cartilage T₂ measurements after contrast administration will lead to systematic errors in the quantification of cartilage degradation. Copyright © 2010 John Wiley & Sons, Ltd.