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化学交换饱和转移(CEST)MRI是一种新兴的基于饱和质子与周围水中质子化学交换的体内分子成像技术,将传统解剖成像扩展到组织酸碱度成像及体内多种生化代谢成像,具有无辐射、非侵入性等显著优势。目前CEST在心血管MRI的应用研究刚刚起步。本文主要对其原理及其在心脏MRI的临床应用研究进展进行综述。 相似文献
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化学交换饱和转移成像(chemical exchange saturation transfer,CEST)技术是一种新型磁共振成像技术,它可利用磁化传输比不对称(magnetization transfer ratio asymmetry,MTRasym)分析产生半定量的结果,对肌骨系统相关疾病的早期诊断和手术决策具有重要意义.传统MRI只能反映病变的形态学差异,很难为疾病的早期诊断提供帮助.CEST技术具有无侵入性和定量检测的优势,已应用于骨关节炎的早期诊断、椎间盘变性及软骨修复手术术后评估等.作者重点总结了CEST的原理、信号测定及其在肌肉骨骼系统的临床应用. 相似文献
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胶质瘤是最常见的原发性中枢神经系统肿瘤,侵袭性强,预后极差。其生长过程中伴随着肿瘤组织内蛋白质、谷氨酸、胺等物质含量的改变。化学交换饱和转移成像(Chemical exchange saturation transfer,CEST)是一种依赖于酰胺(-NH)、胺(-NH2)和羟基(-OH)基团中可移动质子和自由水进行化学交换的新型无创性MRI技术,从分子水平反映组织内蛋白质或多肽中可移动质子含量及pH值的变化。该技术可发现并量化胶质瘤内部分子水平的改变。本文就CEST技术原理及在胶质瘤术前诊断及鉴别诊断、分级、分子分型预测、疗效评估的研究进展及CEST技术存在的不足进行综述。 相似文献
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磁共振氨基质子转移(amide proton transfer,APT)成像是一种基于化学交换饱和转移技术且可反映生物组织中内源性游离蛋白和肽类含量以及氨基质子交换速率的无创性分子磁共振成像方法。APT加权图像是通过对Z谱中水频率两侧±3.5 ppm处的非对称性磁化转移率进行计算得到的。近年来,APT磁共振成像(magnetic resonance imaging,MRI)已被越来越多地应用于疾病诊断中。本文针对目前APT MRI在临床应用和科学研究方面的进展予以综述。 相似文献
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缺血性脑卒中是致残率及致死率均较高的脑血管疾病。影像学检查对于精准诊疗缺血性脑卒中具有重要作用。氨基质子转移(APT)成像是一种新型化学交换饱和转移(CEST)成像技术,可反映组织pH值变化,在评估缺血性脑卒中组织代谢微环境、指导治疗及评估预后等方面展现出巨大潜能。本文对APT成像技术的基本原理及其在缺血性脑卒中的研究及应用进展进行综述。 相似文献
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化学交换饱和转移(chemical exchange saturation transfer,CEST)是一种新兴的分子成像技术,通过分子间化学交换现象间接获得代谢物浓度信息,进行疾病诊断、预后评估等.然而得到的CEST信号并不是单纯来自化学交换,而混杂了诸如传统磁化转移效应(magnetization transfer,MT)、直接饱和效应(direct water saturation,DS)、核奥氏效应(nuclear overhauser enhancement,NOE)等效应.去除或利用这些效应以提高量化的准确度和成像质量是向临床转化的关键. 相似文献
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本文概述了氨基质子转移(amide proton transfer,APT)技术与化学交换饱和转移(chemical exchange saturation transfer,CEST)技术的关系、APT技术的原理、影响APT技术的诸多因素,特别是在体APT成像需研究核奥氏效应(nuclear Overhauser effect,NOE)的重要性。阐述了APT技术的应用,主要有p H成像、温度成像、APT加权像在各器官组织的临床应用。 相似文献
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Transvaginal color Doppler imaging 总被引:10,自引:0,他引:10
Transvaginal color Doppler was used to assess circulation in pelvic vessels in a group of 64 patients including 15 patients with fertility problems, 18 patients with pelvic tumors, 2 cases of suspected ectopic pregnancy, and 29 pregnant patients with fetuses between 6 weeks and 10 weeks, menstrual age. Blood flow was successfully displayed by color Doppler in the external and internal iliac arteries, and the uterine arteries, but flow in ovarian arteries could not be visualized. In the subgroup of patients with pelvic tumors, neovascularization of tumor tissue was documented in 6 out of 10 cases of uterine fibroma and in 2 cases of ovarian cancer. In 6 cases involving benign ovarian pathology, no abnormal blood supply was observed. A comparison between the characteristics of blood flow within uterine fibromas and ovarian malignancies showed lower impedance and higher blood velocity in cases of malignancy. In early pregnancy blood flow in the umbilical artery could be visualized by color Doppler starting from the 6th week and flow in the aorta from the 8th week. Flow in the trophoblasts was observed with an overall success rate of 59% and successfully demonstrated in 1 out of 2 cases of ectopic pregnancy. 相似文献
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目的探讨分段读出扩散加权成像(RS-EPI DWI)相对于单次激发平面回波扩散加权成像(SS-EPI DWI)在鼻咽癌检查中的价值。方法收集30例经病理证实的未做任何治疗的鼻咽癌患者,采用Siemens 3.0 T Skyra磁共振扫描仪对患者常规平扫加增强扫描基础上加做鼻咽的轴位RS-EPI DWI及SS-EPI DWI序列,分别计算出鼻咽肿瘤区域的信噪比(SNR)、对比噪声比(CNR),以T_1增强轴位图像为参考,计算鼻咽层面图像的变形百分比,测量鼻咽肿瘤长、短径,比较SS-EPI DWI、RS-EPI DWI图像上肿瘤大小的准确性,比较颅底层面磁敏感伪影幅度。结果RS-EPI DWI较SS-EPI DWI图像的SNR(t=34.074,P0.01)、CNR(t=23.120,P0.01)值高,图像变形较轻,相同解剖层面,RS-EPI DWI图像测出的肿瘤大小更接近增强后T1轴位上病灶大小,颅底层面RS-EPI DWI图像磁敏感伪影明显较弱(b值为0 s/mm~2时t=10.634,P0.01,b值为1000 s/mm~2时t=8.219,P0.01),两名医师分别对SS-EPI DWI、RS-EPI DWI的ADC图病灶区进行测值,两组测值在判断病灶扩散受限上统计学差异(t=0.00,P=1.000.05)。结论分段读出扩散加权成像较传统的弥散加权成像图像质量更佳,其临床应用更有价值,对于诊断的准确性具有积极的作用。 相似文献
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生物超声(US)、光声(PA)和磁声(MA)成像均以超声波作为载体,将其结合可获得生物组织的组合图像,充分发挥各成像手段的优势。与单一成像技术相比,联合成像具有更好的分辨率及更高的对比度和敏感度,可更精准地定位病变组织,并辨识出其形态和成分。本文对光声—超声、磁声—超声及磁光声联合成像,尤其内窥式联合成像的研究进展及应用现状进行综述。 相似文献
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Chris Suckow Claudia Kuntner Patrick Chow Robert Silverman Arion Chatziioannou David Stout 《Molecular imaging and biology》2009,11(2):100-106
Purpose The ability to reproducibly and repeatedly image rodents in noninvasive imaging systems, such as small-animal positron emission
tomography (PET) and computed tomography (CT), requires a reliable method for anesthetizing, positioning, and heating animals
in a simple reproducible manner. In this paper, we demonstrate that mice and rats can be reproducibly and repeatedly imaged
using an imaging chamber designed to be rigidly mounted on multiple imaging systems.
Procedures Mouse and rat imaging chambers were made of acrylic plastic and aluminum. MicroCT scans were used to evaluate the positioning
reproducibility of the chambers in multimodality and longitudinal imaging studies. The ability of the chambers to maintain
mouse and rat body temperatures while anesthetized with gas anesthesia was also evaluated.
Results Both the mouse and rat imaging chambers were able to reproducibly position the animals in the imaging systems with a small
degree of error. Placement of the mouse in the mouse imaging chamber resulted in a mean distance of 0.23 mm per reference
point in multimodality studies, whereas for longitudinal studies the mean difference was 1.11 mm. The rat chamber resulted
in a mean difference of 0.46 mm in multimodality studies and a mean difference of 4.31 mm in longitudinal studies per reference
point. The chambers maintained rodent body temperatures at the set point temperature of 38°C.
Conclusions The rodent imaging chambers were able to reproducibly position rodents in tomographs with a small degree of variability and
were compatible with routine use. The embedded anesthetic line and heating system was capable of maintaining the rodent’s
temperature and anesthetic state, thereby enhancing rodent health and improving data collection reliability. 相似文献
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DWIBS是MR成像技术近年来发展的一种新方法.本文对DWIBS的发展、原理及目前在颅脑、神经、胸部、肝脏及腹盆部等部位的临床应用研究进行了全面综述. 相似文献
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组织谐波成像诊断胰腺占位性病变的临床应用 总被引:9,自引:0,他引:9
目的:通过常规基波成像(FI)与组织谐波成像(THI)的对比观察,探讨组织谐波成像在胰腺占位性病变诊断中的价值。方法:对比分折62例胰腺占位病变的基波成像和组织谐波成像的结果。结果:在观察胰腺病灶的边界、内部回声及胰管回声方面,在确定占位性病变的物理性质方面,组织谐波成像优于基波成像。结论:本研究表明,组织谐波成像可提高病变的清晰度及对比度,提高胰腺占位性病变的图像质量,从而提高诊断准确率。 相似文献