快速FLAIR序列MRI在脑梗塞诊断中的应用价值

目的：探讨快速ＦＬＡＩＲ序列ＭＲＩ在脑梗塞诊断中的应用价值。材料和方法：对３５例脑梗塞患者行颅脑常规ＳＥ序列和快速ＦＬＡＩＲ序列ＭＲＩ检查,并对比分析常规Ｔ２Ｗ与ＦＬＡＩＲ成像对病变的显示能力。结果：ＭＲＩ共发现５０个脑梗塞灶。除２个病灶外,４８个病灶ＦＬＡＩＲ成像较ＳＥ序列Ｔ２Ｗ成像显示更为清晰明确,其中３个皮层／皮层下病灶和１个脑室旁病灶仅为ＦＬＡＩＲ成像显示;ＳＥ序列Ｔ２Ｗ与ＦＬＡＩＲ成像显     

磁共振成像在主动脉疾病中的应用(附29例分析)

目的：评价ＭＲＩＳＥ序列，梯度回波（ＧＲＥ）及磁共振血管成像（ＭＲＡ）对主动脉疾病的诊断价值。材料和方法：２９例主动脉疾患，其中主动脉夹层２１例，胸、腹主动脉瘤８例。全部病例采用ＭＲＩＳＥ常规序列及ＧＲＥ技术，４例行ＭＲＡ检查。结果：在ＳＥ及ＧＲＥ序列上２１例胸、腹主动脉夹层均显示真假两腔，其内膜片分别为１９和２１例。破口分别为５和８例。ＭＲＩ及ＭＲＡ能清晰地显示主动脉瘤和瘤体内结构。结论：ＭＲＩ对主动脉疾患具有肯定的诊断价值。以常规ＳＥ序列为基础，辅以ＧＲＥ及ＭＲＡ技术将能对主动脉疾病提供更多的诊断信息。     

肝癌的影像学评价:1.5T MRI与常规CT、US比较

目的：探讨三种非创伤性影像检查方法ＭＲＩ、ＣＴ和ＵＳ在肝癌诊断中的敏感性和准确性。方法：５２例经病理及临床证实的ＨＣＣ行ＭＲＩ,ＣＴ和ＵＳ检查。结果：ＭＲＩ常规序列与ＦＭＰＳＰＧＲ相比,敏感性以ＳＥＴ２Ｗ及ＦＭＰＳＰＧＲ序列为高。对ＨＣＣ检出总的敏感性依次为ＭＲＩ（ＳＥ＋ＦＭＰＳＰＧＲ）８５．８９％,ＣＴ７５．６４％,ＵＳ７１．７９％,＜３ｃｍＨＣＣ,ＭＲＩ检出的敏感性为７１．４２％明显高于ＣＴ（５１．４２％）和ＵＳ（４５．７１％）,对于＞３ｃｍＨＣＣ,三者敏感性相似。ＨＣＣ定性准确性依次为动态增强ＦＭＰＳＰＧＲ（９２．０６％）,常规ＳＥ序列（８５．９３％）,ＣＴ（８４．７４％）,ＵＳ（７５．００％）,ＳＥ序列结合动态增强ＦＭＰＳＰＧＲ对肝癌定性准确性可达９５％,明显优于ＣＴ和ＵＳ。结论：在ＨＣＣ的检出敏感性和定性诊断上,１．５ＴＭＲＩＳＥ序列结合动态增强ＦＭＰＳＰＧＲ明显优于常规ＣＴ和ＵＳ,为肝癌重要的影像学检查手段。     

眶内占位性病变的MRI诊断价值

笔者分析了４０例眶内占位性病变的ＭＲＩ表现并与ＣＴ比较。结果表明ＭＲＩ对眶内占位性病变发现率极高，特别是对视神经的管内段和颅内蔓延或眶外软组织浸润范围的确定较ＣＴ更准确，其多方位扫描功能使定位诊断符合率高达１００％，特别是冠状面对定位诊断的作用极大。据不同组织有不同的ＭＲＩ信号强度变化的特点，结合形态学变化，ＭＲＩ对一些病变可作出定性诊断。     

癫痫的高场强MRI研究

探讨高场强ＭＲＩ对癫痫的病因诊断价值。５７例癫痫患，ＭＲＩ技术包括ＳＥ和ＦＳＥ平扫，增强及ＦＬＡＩＲ序列扫描。结果；引起癫痫的常见原因有脑发育异常，脑软化和颞叶内侧硬化等。结论；ＭＲＩ癫痫是一种有效实用的检查方法，ＦＬＡＩＲ序列对颞叶内侧硬化有其独特的优越性。     

膝关节正常关节软骨及软骨缺损的多序列MR成像比较

目的：筛选ＭＲＩ评价关节软骨的最佳成像序列。材料和方法：应用五种不同ＭＲ序列，包括ＴｌＷＩ、ＰＤＷＩ、Ｔ２ＷＩ、ＳＴＩＲ和３Ｄ－ＧＥ，对６位健康志愿者的正常膝关节和１２个用外科方法制作的直径ｌｍｍ—６ｍｍ的软骨缺损的膝关节标本进行成像比较。结果：与ＳＥ和ＳＴＩＲ序列相比，３Ｄ－ＧＥ序列可作连续薄层扫描，具有高信噪比、高分辨率、良好的组织对比及成像时间短等优点，能清楚显示软骨的厚度及轮廓，并可检出直径小至２ｍｍ的软骨缺损。结论：３Ｄ－ＧＥ序列是检查关节软骨病变的最佳序列，若辅以ＴｌＷＩ和ＳＴＩＲ成像，有利于关节软骨与关节液和脂肪组织的区分，可进一步提高ＭＲ诊断关节软骨病变的准确性     

磁共振成像在主动脉疾病中的应用

评价ＭＲＩＳＥ序列，梯度回波及磁共振血管成像对主动脉疾病的诊断价值。材料和方法：２９例主动脉疾患，其中主动脉夹层２１例，胸，腹主动脉瘤８例。全部病例采用ＭＲＩ ＳＥ常规序隐及ＧＲＥ技术，４例行ＭＲＡ检查。结果；在ＳＥ及ＧＲＥ序列上２１例胸，腹主动脉夹层均显示真假两腔，其内膜分别为１９和２１例。     

MRI新技术在临床脑梗塞诊断中的应用

本文就增强ＭＲＩ、ＭＲ血管造影,ＦＬＡＩＲ序列ＭＲＩ、灌注ＭＲＩ、弥散加权ＭＲＩ、ＭＲＳ等ＭＲ新技术在临床脑梗塞诊断中的应用作一综述。     

常见眼球后病变MRI信号模式的研究(附47例报告)

目的：为提高ＭＲＩ诊断和鉴别诊断眼球后病变能力，通过分析ＭＲＩ信号征象，建立常见眼球后病变ＭＲＩ信号变化模式。材料和方法：４７例球后病变，术前均接受了ＭＲＩ检查。男２８例，女１９例。检查使用超导ＭＲ成像系统。常规ＳＥ序列。Ｔ１Ｗ和Ｔ２Ｗ的多回波成像。结果：根据其ＭＲＩ信号征象，可分为四种信号模式。眼眶多数常见病变的ＭＲＩ信号改变具有一定特征性。结论：可以根据病变部位以及ＭＲＩ信号特征对大多数的眼眶病变做出正确的定性诊断。     

动态增强MRI在原发性肝癌诊断中的应用

动态增强检查是腹部常规ＳＥ序列成象的补充方法，对肝肿瘤的诊断和鉴别诊断有很大帮助。本介绍了肝脏动态增强ＭＲ成像的常用序列及造影剂的使用和作用原理，简述了正常肝脏和原发性肝癌的动态增加ＭＲ成象特点。     

抑脂技术和动态增强MRI在胰岛素瘤诊断中的价值探讨

目的 探讨抑脂技术和动态增强MRI在胰岛素瘤术前定位诊断中的价值。方法 12例手术病理证实的胰岛素瘤患者术前行MR检查，扫描序列包括：横断面SE T1WI，快速自旋回波(FSE)T2WI，加脂肪抑制技术的T1WI和T2WI(即T1WI FS和T2WI FS)，快速多层面扰相梯度回波(FMPSPGR)序列作动态增强扫描。结果 在常规T1WI和T2WI序列仅检出4例肿瘤，表现为T1WI稍低信号和T2WI稍高信号。在T1WI FS上7例呈均匀低信号，显示清晰；在T2WI FS上6例病灶呈不同程度的高信号。快速动态增强扫描(FMPSPGR)检出11例肿瘤，在动脉期7例肿瘤明显强化呈高信号，4例轻度强化呈稍高信号，1例无明显强化呈等信号，胰腺实质期和门脉期6例仍呈高信号，6例呈等信号。与手术后病理结果比较，动态增强MRI对胰岛素瘤术前定位诊断准确率为91．7％(11／12)。结论 动态增强MRI是胰岛素瘤术前定位诊断敏感而准确的方法。     

高场强MRI在胰腺癌中的诊断价值

目的:探讨高场强MRI在胰腺癌中的诊断价值。方法:收集本院经手术病理和/或临床、影像检查证实的胰腺癌18例,均作了MRI FSPGR序列非抑脂T1WI和抑脂T1WI平扫及动态增强扫描以及磁共振胰胆管成像(MRCP),分析其MRI及MRCP表现。结果:18例胰腺癌中,非抑脂T1WI呈低信号12例,等信号6例;抑脂T1WI呈低信号15例,等信号3例,动态增强扫描,动脉期所有病灶均表现为不强化或强化不明显呈低信号;MRCP显示胆总管扩张12例,胰管扩张12例,“双管征”8例。结论:高场强MRI对胰腺癌的检出和诊断具有重要价值。     

膝关节外伤性骨髓水肿的MR脂肪抑制术成像

目的 分析膝外伤所致周围骨质骨髓水肿的ＭＲＩ表现,探讨其形成的病理学机制。材料与方法 ＭＲＩ检查发现膝关节外伤性骨髓水肿４３例,除常规Ｔ１、Ｔ２加权像检查外,均有矢状面和冠状面脂肪抑制术检查。结果 ４３例患者中共发现膝关节周围水肿６８处,常规Ｔ１、Ｔ２加权像能显示大部分病灶,均呈相对低信号,脂肪抑制术后均可显示,呈明显的高信号。结论 ＭＲＩ脂肪抑制Ｔ２加权像有准确显示膝关节周围骨质的外伤性骨髓水肿     

Interactive body magnetic resonance fluoroscopy using modified single-shot half-Fourier rapid acquisition with relaxation enhancement (RARE) with multiparameter control

PURPOSE: To develop a technique for interactive fluoroscopic abdominal magnetic resonance imaging (MRI) based on a single-shot half-Fourier rapid acquisition and relaxation-enhanced sequence. MATERIALS AND METHODS: The sequence was modified by incorporating inner-volume excitation, driven-equilibrium signal enhancement, and reduced flip angle refocusing pulses. Contrast control was provided by integrating "on-the-fly" selection of phase encoding view order, fat suppression, and section thickness. The resulting sequence was evaluated with phantom experiments to quantify the signal-to-noise ratio (SNR) effects of the modifications and in healthy volunteers for imaging the bile ducts, stomach, and duodenum using water and gaseous contrast media. RESULTS: Observed SNR relating to driven-equilibrium and flip angle scaling matched theoretical predictions. Volunteer examinations demonstrated the ability of the modified sequence to provide interactive, artifact-free imaging of the abdomen, including switching between conventional proton density-weighted, T2-weighted imaging and "hydrographic" projection imaging. CONCLUSION: Refinement of this technique may provide an abdomino-pelvic imaging capability similar in concept to real-time ultrasound, but with the advantages of MRI.     

低场磁共振成像对卵巢巧克力囊肿与囊性畸胎瘤鉴别诊断价值的研究

目的 探讨低场磁共振成像(MRI)在卵巢巧克力囊肿与囊性畸胎瘤临床鉴别诊断中的价值.方法 回顾性分析经手术及病理证实的卵巢巧克力囊肿22例,囊性畸胎瘤13例,分析各自的MRI表现特点.结果 22例巧克力囊肿术前诊断正确19例,其中3例术前诊断为囊性畸胎瘤,MRI诊断符合率86％(19/22);13例囊性畸胎瘤术前诊断正确12例,1例术前判断为巧克力囊肿,符合率92％(12/13).所有巧克力囊肿和畸胎瘤病例在SET1WI序列下均可见到病灶内高信号区.当使用短时间反转恢复序列(STIR)脂肪抑制序列时,所有高信号区可见不同程度信号减低;当使用GRE同、反相位T1加权成像时,畸胎瘤内的T1WI高信号病灶在反相位图像上会出现明显信号减低区,而巧克力囊肿不会出现信号减低区.结论 卵巢巧克力囊肿与囊性畸胎瘤MRI诊断准确性较高.使用GRE同、反相位T1加权成像对两者的鉴别诊断有特殊价值.     

Rapid fat suppression in MRI of the breast with short binomial pulses

PURPOSE: To develop a faster method of fat suppression for use in dynamic contrast enhanced MRI of the breast. MATERIALS AND METHODS: A method of fast fat suppression is presented using spatially nonselective rapid binomial pulses. In contrast to conventional binomial frequency-selective pulses, these short pulses are applied without interpulse delay, allowing for very rapid spectrally selective excitation. RESULTS: Effective water excitation and fat suppression were achieved in breast MRI at 3.0 Tesla with total excitation time as low as 160 microsec, which is several times shorter than the excitation time of currently used fat suppression techniques. Rapid fat suppression comes at the expense of increased specific absorption rate (SAR) and mildly degraded quality of suppression. A flexible tradeoff of short imaging time vs. SAR can be made to optimize imaging speed for fat-suppressed breast MRI. CONCLUSION: Rapid binomial pulses can be used for dynamic contrast enhanced breast MRI with excitation times significantly shorter than currently used fat suppression pulses. Shorter excitation time allows more rapid imaging, allowing greater temporal and spatial resolution for characterization of breast lesions.     

Gadolinium enhancement: improved MRI detection of retinoblastoma extension into the optic nerve

We performed T1-, T2-, proton density-weighted, and T1-weighted gadolinium-enhanced MRI on 24 patients with retinoblastoma, using a 1.5 T superconducting unit and head and orbital surface coil imaging. All patients underwent a complete ophthalmologic examination, including B-scan ultrasonography. CT was performed on 10 of 24 patients. Pathologic correlation was obtained in 18 patients who required enucleation. Contrast-enhanced T1-weighted MRI with fat suppression was the sequence most sensitive to optic nerve extension and provided the greatest differentiation between tumor and uninvolved extrascleral tissue. Retinoblastoma demonstrated contrast enhancement. Received: 28 September 1995 Accepted: 9 January 1996     

基于骰骨MRI的糖尿病足影像组学特征

目的 探究基于MRI影像组学特征辅助诊断糖尿病足（DF）的可行性。 方法 回顾性分析2018年8月至2020年8月于上海中医药大学附属上海市中西医结合医院行足部MRI检查的127例因足部疾患就诊患者的临床资料,其中男性83例、女性44例,年龄16~88（59.3±14.8）岁。根据患者临床诊断的不同分为DF组（85例）和非DF组（42例）;根据影像组学特点,采用简单随机抽样法,将患者以3∶2的比例随机分为训练组（76例）和测试组（51例）。在MRI的T1加权成像（WI）序列和质子密度加权成像（PDWI）压脂序列矢状面图像上勾画骰骨,提取影像组学特征参数,并构建T1WI序列模型、PDWI压脂序列模型及联合模型,联合模型包括性别、年龄、骨髓信号和影像组学特征参数。通过3组模型参数最大绝对值归一化的预处理,经过最优特征和模型选择筛选出最优特征维度。采用受试者工作特征（ROC）曲线,计算曲线下面积（AUC）,评估影像组学特征诊断DF的效能。2组间年龄的比较采用独立样本t检验,2组间性别和中足骨骨髓信号异常的比较采用χ2检验。 结果 DF组和非DF组患者在年龄、男女比例及中足骨骨髓信号异常间的差异均有统计学意义（t=29.2,χ2=17.15、6.53,均P<0.05）。T1WI序列模型、PDWI压脂序列模型和联合模型最终分别筛选出9、7和10个最优特征维度。支持向量机模型区别DF和非DF患者在T1WI序列模型上训练组和测试组的AUC分别为0.86和0.84,准确率分别为78%和69%; PDWI压脂序列模型上训练组和测试组的AUC分别为0.85和0.83,准确率分别为82%和78%;而联合模型上训练组和测试组的AUC分别为0.93和0.85,准确率分别为84%和76%。T1WI序列模型与PDWI压脂序列模型诊断效能相当,而联合模型优于二者单独应用。 结论 MRI影像组学特征能有效区分DF和非DF,有望为DF影像诊断提供一种新型、高效、无创的手段。     

Lipid-suppressed single- and multisection proton spectroscopic imaging of the human brain.

Spectroscopic images of the brain have great potential in disease diagnosis and treatment monitoring. Unfortunately, interfering lipid signals from subcutaneous fat and poor water suppression due to magnetic field inhomogeneities can make such images difficult to obtain. A pulse sequence that uses inversion recovery for lipid suppression and a spectral-spatial refocusing pulse for water suppression is introduced. In contrast to methods that eliminate fat signal by restricting the excited volume to lie completely within the brain, inversion-recovery techniques allow imaging of an entire section without such restrictions. In addition, the spectral-spatial pulse was designed to provide water suppression insensitive to a reasonable range of B0 and B1 inhomogeneities. Several data processing algorithms have also been developed and used in conjunction with the new pulse sequence to produce metabolite maps covering large volumes of the human brain. Images from single- and multisection studies demonstrate the performance of these techniques.     

MRI诊断隐睾症的临床价值

目的:探讨隐睾的MRI表现及其诊断价值。方法:对16例临床怀疑隐睾症的患者进行MRI检查,作T1WI、T2WI,并加脂肪抑制,对其MRI表现进行分析,所有病例经手术证实。结果:16例隐睾(共19枚)呈椭圆形或结节状,T1WI为等、低信号,T2WI为高信号,T2WI加抑脂信号最高。所有病例均由MRI正确诊断。结论:MRI对隐睾能准确定位,其表现具有特征性,是诊断隐睾症有价值的方法。