动态磁敏感对比增强MRI和动态对比增强MRI鉴别诊断胶质瘤复发和放射性脑损伤

目的 探讨动态磁敏感对比增强MRI（DSC-MRI）及动态对比增强MRI（DCE-MRI）在鉴别脑胶质瘤术后放化疗后复发和放射性脑损伤中的临床应用价值。方法 对19例经临床病理确诊为脑胶质瘤患者在术后、放化疗前、放化疗后定期行DSC及DCE检查,得到相关的血流动力学参数值并将灌注成像影像诊断结果与临床最终诊断结果对照,分析各灌注参数在鉴别诊断中的价值。结果 11例为胶质瘤复发,8例为放射性脑损伤。胶质瘤复发患者的rCBF、rCBV、K_trans、V_e及riAUC值均明显高于放射性脑损伤患者（P均<0.05）;而K_ep、V_p值在胶质瘤复发或放射性脑损伤患者差异无统计学意义（P=0.37、0.22）。K_trans联合rCBV共同诊断,并、串联试验中鉴别诊断的敏感度分别为90.9%、72.7%;特异度分别为62.5%、100%。结论 DCE及DSC均可鉴别肿瘤复发或放射性脑损伤。K_trans、riAUC及rCBV诊断效能略高于V_e及rCBF,联合应用rCBV及K_trans可提高诊断正确率。     

基于组稀疏典型相关分析方法的影像遗传学方法在精神分裂症中的应用

目的 采用影像遗传学研究方法探索精神分裂症患者的影像学数据与遗传学数据间的相关性。方法 提出一种组稀疏典型相关分析方法,在稀疏典型相关分析模型的基础上增加组稀疏惩罚项λ₁‖u‖_G和λ₂‖v‖_G进行变量组选择;对于选择的特征组,再利用组内惩罚项τ₁‖u‖₁和τ₂‖v‖₁进行组内的变量选择。采用基于组稀疏典型相关分析方法的影像遗传学方法分析精神分裂症患者脑区与相关基因位点的相关性,并验证其稳定性和筛选生物标记物的能力。结果 采用组稀疏典型相关分析方法获得了多组精神分裂症相关脑区和基因,其中左侧脑岛与基因AKT1的相关性最大,相关系数为0.653 8;右侧直回与基因DAOA和MAGI2的相关系数均大于0.6。组稀疏典型相关分析筛选出的特征的相关系数为0.626 9±0.016 1,稀疏典型相关系数为0.625 5±0.018 1。经过10次实验,在采用组稀疏典型相关分析方法筛选出的最相关的前20组特征中,属于已知的精神分裂症相关75个基因的比例大于随机选出的非相关基因的比例。结论 通过组稀疏典型相关分析方法能够筛选出多组精神分裂症的相关基因和脑区,为今后对精神分裂症等复杂精神类疾病的研究提供了新的思路。     

PET/MRI观察朗格汉斯细胞组织细胞增生症

目的 观察朗格汉斯细胞组织细胞增生症（LCH）的¹⁸F-FDG PET/MRI表现。方法 回顾性分析11例经病理学证实的LCH患者PET/MRI所示各系统病灶部位、数目、形态及最大标准摄取值（SUV_max）。结果 11例LCH中,8例为症状或影像学未缓解、3例为影像学缓解病例;其中7例累及全身多系统,4例仅累及骨骼系统或垂体,临床表现与病变累及范围相关。8例未缓解LCH中,PET/MRI共检出38个病灶,多表现为不同程度FDG摄取增高,SUV_max为1.23~13.00。结论 LCH累及范围多较广,PET/MRI中病变多呈不同程度FDG摄取增高。     

碳青霉烯类药物非敏感肠杆菌科细菌基因型研究

摘要：目的：探讨临床分离的碳青霉烯类药物非敏感肠杆菌科细菌的基因型。 方法：收集2010年1月至2013年6月临床标本中分离的碳青霉烯类药物非敏感肠杆菌科细菌110株,K-B纸片扩散法检测细菌对临床常用药物的敏感性,纸片扩散表型确证试验检测超广谱β-内酰胺酶(ESBLs),改良Hodge试验（MHT）检测碳青霉烯酶表型,PCR、DNA测序及BLAST比对等方法确定菌株耐药基因型。 结果：110株碳青霉烯类非敏感肠杆菌科细菌中,MHT阳性77株(70.0%)。31株大肠埃希菌、1株产气肠杆菌和1株黏质沙雷菌检出bla_KPC-2基因,5株阴沟肠杆菌和1株产气肠杆菌分别检出bla_IMP-26和bla_VIM-2基因。36株32.7%菌株ESBLs表型试验阳性,主要检出bla_CTX-M-15、bla_SHV-12和bla_CTX-M-3 3种ESBLs基因型。 结论:本项研究碳青霉烯类非敏感肠杆菌科细菌以bla_KPC-2基因型为主,其次为bla_IMP-26和bla_VIM-2基因型。     

携带blaNDM-1基因的ST22型肺炎克雷伯菌引起新生儿医院感染

摘要：目的：探讨耐碳青霉烯类肺炎克雷伯菌临床株的分子流行病学特征,为医院感染的控制和预防提供指导。 方法: 3株对碳青霉烯类耐药的肺炎克雷伯菌临床菌株分离自山东某医院新生儿病房患儿的抽吸痰液和血液标本;用Vitek 2 Compact系统进行细菌鉴定和药敏试验;改良Hodge试验检测菌株是否产碳青霉烯酶;PCR检测菌株携带的碳青霉烯酶基因(bla_KPC、bla_BIC、bla_OXA-48、bla_NDM、bla_IMP、bla_VIM、bla_{SPM、blaAIM、blaGIM、blaSIM和blaDIM)、β-内酰胺酶基因（blaCTX-M、blaSHV、blaTEM和blaOXA-1)、AmpC酶基因 (blaMOX、blaCIT、blaDHA、blaACC和blaEBC)、喹诺酮耐药相关基因(qnrA、qnrB、qnrS、oqxA和oqxB)和磷霉素耐药基因(fosA3),测序确认其基因型;用多位点序列分型和脉冲场凝胶电泳分析细菌的同源性;质粒接合和Southern杂交试验分析质粒的特性,并进行质粒不相容群检测。 结果: 3株肺炎克雷伯菌Hodge试验呈阳性,且对大部分抗菌药物耐药,均携带blaNDM-1、blaTEM-1、fosA3、oqxA和oqxB基因。脉冲场凝胶电泳显示3株菌的带型完全一致,属于同一克隆,而且多位点序列分型也都是ST22,提示存在流行。质粒接合和Southern杂交试验表明供体菌携带blaNDM-1质粒（pTA-NDM）可通过接合方式转移到受体菌,且质粒大小约220 000 bp,不相容群分型属于IncA/C型质粒。 结论: 同时携带blaNDM-1、blaTEM-1、fosA3、oqxA和oqxB基因的ST22型肺炎克雷伯菌在新生儿病房中的流行属国内外首次报道,应引起重视。}     

三维超声及MRI定量评估胎儿小脑蚓部

目的 探讨三维超声和MRI定量评估胎儿小脑蚓部发育异常的临床价值。方法 收集三维超声和MRI获得胎头矢正中切面显示颅内无异常70胎(正常组)和小脑蚓部发育异常(不包括蚓部完全缺失)20胎,两种检查在24 h内完成。比较三维超声和MRI胎头矢正中切面图像,并测量小脑蚓部前后径(AP)、上下径(CC)。比较两种影像学检查方法测量值的相关性。结果 正常组三维超声测量的小脑蚓部AP、CC与MRI相关(R_AP²=0.951,R_CC²=0.959,P均<0.001);与三维超声图像比较,MRI图像质量更佳,可显示脑干的全长及超声不易显示的窦汇,但三维超声可根据小脑幕的位置确定窦汇的位置。小脑蚓部发育不良胎儿的蚓部AP、CC的Z分数为-5.0~-1.5,典型Dandy-Walker畸形的蚓部AP、CC的Z分数均小于-6.0,三维超声测量小脑蚓部AP、CC与MRI相关(R_AP²=0.978,R_CC²=0.942,P均<0.001)。结论 测量小脑蚓部的AP、CC并建立孕周参考值,可有效地评估胎儿小脑蚓部发育。三维超声和MRI均可准确测量小脑蚓部的AP、CC,且两种方法的测量值相关。     

动态增强MRI定量参数与乳腺癌分子亚型的关系

目的 探讨不同分子亚型乳腺癌动态对比增强MRI(DCE-MRI)定量参数及其与预后因子的关系。 方法 回顾性分析78例乳腺浸润性癌患者治疗前的MRI,测量定量参数K^trans、K_ep和V_e。测定免疫组化指标ER、PR和HER-2,并对分子亚型进行归类。比较不同分子亚型间及雌激素受体(ER)、孕激素受体(PR)、人类表皮生长因子受体(HER-2)不同表达状态时的DCE-MRI定量参数。 结果 最终68例入组,其中Luminal A型24例,Luminal B型19例,HER-2+型10例,三阴性乳腺癌(TNBC)15例。K_ep值在不同分子亚型间差异有统计学意义(P<0.01)。Luminal A型和TNBC的K^trans、K_ep和V_e值的差异均有统计学意义(P均<0.05)。4个亚型中,TNBC的K^trans和K_ep值最大,V_e值最小。ER-者K_ep值高于ER+者;PR-者K_ep值亦高于PR+者,PR-者与PR+者K^trans差异有统计学意义。 结论 通过K^trans、K_ep和V_e值可鉴别Luminal A型乳腺癌和TNBC;不同分子亚型及不同ER、PR表达状态的乳腺癌的K_ep值不同。     

对比PET/MRI与PET/CT检出肝转移癌效能

目的 对比观察PET/MRI与PET/CT检出肝转移癌的效能。方法 纳入78例共409个肝转移癌病灶,比较PET/CT及PET/MRI检出肝转移癌的阳性率。对A组50例283个病灶先行PET/CT后行PET/MR检查,B组28例126个病灶先行PET/MR后行PET/CT。采用Spearman秩相关分析和Wilcoxon秩和检验评价组内不同检查方法所获病灶最大标准摄取值（SUV_max）的相关性及其差异。结果 PET/MRI对肝转移癌的检出率（381/409,93.15%）明显高于PET/CT（285/409,69.68%,P<0.05）。A组PET/MRI的阳性率（266/283,93.99%）明显高于PET/CT（197/283,69.61%,P<0.05）;PET/MRI与PET/CT的SUV_max高度相关（r=0.84,P<0.05）,而PET/MRI的SUV_max显著高于PET/CT的SUV_max（P<0.05）。B组PET/MRI阳性率（115/126,91.27%）明显高于PET/CT（88/126,69.84%,P<0.05）;PET/MRI与PET/CT的SUV_max中度相关（r=0.74,P<0.05）,且差异无统计学意义（P>0.05）。结论 PET/MRI检出肝转移癌效果优于PET/CT;二者所获SUV_max相关性较好。     

体素内不相干运动MRI评估子宫肌瘤血流灌注及分子扩散状态的观察者间一致性

目的 探讨体素内不相干运动(IVIM)MRI评估子宫肌瘤血流灌注及分子扩散状态的不同观察者间的一致性。方法 采用3.0T MR仪对23例子宫肌瘤患者进行T2WI及多b值DWI。2名观察者利用后处理软件选择子宫肌瘤最大层面勾画ROI,使用双指数模型,生成IVIM MRI相关的参数图(D图、D^*图、f图),得到数值分布的直方图,分别计算各参数的位于直方图左侧第25%、50%、75%位置的数值及平均值,比较2名观察者测量数据的一致性。结果 23例子宫肌瘤患者中,2名观察者对12例选择最大层面的结果一致;2名观察者间测得的23例子宫肌瘤的D_mean、D25、D50、D75值平均值差值为0~0.07 mm²/s,f_mean、f25、f50、f75值平均值差值为0~0.01,D^*_mean、D^*25、D^*50、D^*75值平均值差值为0~5.38 mm²/s;2名观察者测量的25个IVIM MRI参数的ICC值> 0.9,测量的33个IVIM MRI参数的ICC值> 0.8。结论 采用IVIM MRI评估子宫肌瘤血流灌注及分子扩散状态的不同观察者间的一致性好,这种方法可行。     

酶清洗剂在医疗器械清洗中的应用研究

任何残留的有机物,血块、脓液、蛋白质、黏液都会妨碍消毒灭菌因子与微生物的有效接触,形成细菌或细菌芽孢的保护膜而影响灭菌效果。灭菌前的彻底清洗是十分重要的_[1]。一般认为清洗程度至少达到_[2]: 降低物品上的生物负荷;去除有机、无机污染物;灭菌时达到无菌保证水平(SAL)10 _-6。随着对清洗重要性的认识,酶清洗剂越来越广泛地应用在各种医疗器械的清洗过程,其中不乏对酶清洗剂应用的研究。为了更好地发挥酶清洗剂的作用,现将酶清洗剂在医疗器械清洗中的应用研究综述如下。     

Cardiac Cell Tracking with MRI Reporter Genes: Welcoming a New Field

Research into cell therapy based cardiac repair and regeneration has experienced explosive growth over the last decade, however further progress is hindered by an inability to serially and non-invasively image cell survival and fate decisions following implantation. Recent advances in magnetic resonance imaging (MRI) reporter gene techniques have enabled in vivo imaging of cell survival, proliferation, migration, and differentiation, however this has mostly been performed in stationary tissues. A small series of recent studies has examined the possibility of using MRI reporter genes to track the survival of cells injected into the heart following myocardial infarction. In this review, we seek to frame the emerging field of MRI reporter gene based cardiac cell tracking within the larger framework of the needs of cardiac regeneration therapy and the more established field of MRI cell tracking. While initial studies have demonstrated a promising ability to track the viability and proliferation of cells used for cell therapy, the ultimate goal of MR reporter gene imaging in the heart remains the ability to simultaneously correlate cell fate decisions with additional measures of structural and functional recovery.     

Molecular MRI of Thrombosis

This review focuses on recent approaches in using targeted MRI probes for noninvasive molecular imaging of thrombosis. Probe design strategies are discussed: choice of molecular target; nanoparticle versus small-molecule probe; and gadolinium versus iron oxide imaging reporter. Examples of these different design strategies are chosen from the recent literature. Novel contrast agents used to image direct and indirect binding to fibrin have been described as well as direct binding to activated platelets. Emphasis is placed on probes where utility has been demonstrated in animal models or in human clinical trials.     

Molecular MRI of Thrombosis

This review focuses on recent approaches in using targeted MRI probes for noninvasive molecular imaging of thrombosis. Probe design strategies are discussed: choice of molecular target; nanoparticle versus small-molecule probe; and gadolinium versus iron oxide imaging reporter. Examples of these different design strategies are chosen from the recent literature. Novel contrast agents used to image direct and indirect binding to fibrin have been described as well as direct binding to activated platelets. Emphasis is placed on probes where utility has been demonstrated in animal models or in human clinical trials.     

MR-guided interventions of the prostate gland.

In recent years MR imaging has played an increasingly important role in the diagnosis and treatment of prostate cancer. MR imaging of the prostate allows a clear delineation of the anatomic structures and prostate tumors when performing interventions such as biopsies, brachytherapy or thermal therapy of the prostate gland. MRI robotic assistance will improve the accuracy of the interventions. Due to the advantages of MR imaging MR-guided prostate interventions will play an increasing role in future.     

Advances and utility of diagnostic ultrasound in musculoskeletal medicine

Musculoskeletal ultrasound (US) can serve as an excellent imaging modality for the musculoskeletal clinician. Although MRI is more commonly ordered in the United States for musculoskeletal problems, both of these imaging modalities have advantages and disadvantages and can be viewed as complementary rather than adversarial. For diagnostic US, relative recent advances in technology have improved ultrasound’s ability to diagnose a myriad of musculoskeletal problems with enhanced resolution. The structures most commonly imaged with diagnostic musculoskeletal US, include tendon, muscle, nerve, joint, and some osseous pathology. This brief review article will discuss the role of US in imaging various common musculoskeletal disorders and will highlight, where appropriate, how recent technological advances have improved this imaging modality in musculoskeletal medicine. Additionally, clinicians practicing musculoskeletal medicine should be aware of the ability as well as limitations of this unique imaging modality and become familiar with conditions where US may be more advantageous than MRI.     

PET/MRI研究进展

近年来,以PET/CT为代表的多模式显像技术已成功应用于科研与临床。MRI在多方面优于CT,PET/MRI融合显像可提供分子、形态与功能信息,具有较大潜力,使其成为研究热点,并取得了一定进展;但其研制过程中仍存在一系列问题,若能合理解决,将为分子影像学带来深远影响。     

时空编码单扫描磁共振成像的基本原理及重建方法

单扫描磁共振成像技术凭借其良好的时间分辨率,近年来在扩散成像、实时动态三维成像、功能成像等生物医学领域得到广泛应用。在众多单扫描磁共振成像方法中,回波平面成像(EPI)是最常用的一种方法,但它存在一些局限性,特别是在高场条件下,其对磁场不均匀及化学位移效应十分敏感。基于时空编码的单扫描磁共振成像新方法,其对不均匀磁场及化学位移伪影有很好的鲁棒性,并延续了EPI良好的时间分辨率。作者主要阐述时空编码单扫描成像方法的基本原理、特性,时空编码图像的超分辨重建方法及其在生物医学领域的应用。     

Molecular Imaging in Synthetic Biology,and Synthetic Biology in Molecular Imaging

Biomedical synthetic biology is an emerging field in which cells are engineered at the genetic level to carry out novel functions with relevance to biomedical and industrial applications. This approach promises new treatments, imaging tools, and diagnostics for diseases ranging from gastrointestinal inflammatory syndromes to cancer, diabetes, and neurodegeneration. As these cellular technologies undergo pre-clinical and clinical development, it is becoming essential to monitor their location and function in vivo, necessitating appropriate molecular imaging strategies, and therefore, we have created an interest group within the World Molecular Imaging Society focusing on synthetic biology and reporter gene technologies. Here, we highlight recent advances in biomedical synthetic biology, including bacterial therapy, immunotherapy, and regenerative medicine. We then discuss emerging molecular imaging approaches to facilitate in vivo applications, focusing on reporter genes for noninvasive modalities such as magnetic resonance, ultrasound, photoacoustic imaging, bioluminescence, and radionuclear imaging. Because reporter genes can be incorporated directly into engineered genetic circuits, they are particularly well suited to imaging synthetic biological constructs, and developing them provides opportunities for creative molecular and genetic engineering.     

SMASH, SENSE, PILS, GRAPPA: how to choose the optimal method

Fast imaging methods and the availability of required hardware for magnetic resonance tomography (MRT) have significantly reduced acquisition times from about an hour down to several minutes or seconds. With this development over the last 20 years, magnetic resonance imaging (MRI) has become one of the most important instruments in clinical diagnosis. In recent years, the greatest progress in further increasing imaging speed has been the development of parallel MRI (pMRI). Within the last 3 years, parallel imaging methods have become commercially available, and therefore are now available for a broad clinical use. The basic feature of pMRI is a scan time reduction, applicable to nearly any available MRI method, while maintaining the contrast behavior without requiring higher gradient system performance. Because of its faster image acquisition, pMRI can in some cases even significantly improve image quality. In the last 10 years of pMRI development, several different pMRI reconstruction methods have been set up which partially differ in their philosophy, in the mode of reconstruction as well in their advantages and drawbacks with regard to a successful image reconstruction. In this review, a brief overview is given on the advantages and disadvantages of present pMRI methods in clinical applications, and examples from different daily clinical applications are shown.     

乳腺癌MRI诊断进展

MR已成为临床和影像医师评估乳腺疾病的一项强有力的工具。DWI和动态对比增强MRI（DCE-MRI）是目前临床MR检查的首选。近年来,MRI新技术的发展,如钠磁共振成像、化学能量饱和转移（CEST）和BOLD MRI有望为诊断乳腺疾病提供更有价值的参数,而乳腺放射组学和放射基因组学也已成为乳腺成像的热门话题。本文对MRI新技术在乳腺癌中的应用进展进行综述。