CT灌注成像在胰腺疾病诊断的进展

CT是诊断胰腺疾病的主要辅助检查手段之一,但传统CT扫描在早期发现胰腺疾病,以及占位性病灶的鉴别诊断方面并不能让患者满意.胰腺CT灌注成像是新兴的功能学成像技术,并可以通过血流量、血容量、毛细血管表面通透性等参数显现胰腺局部因病理变化产生的血流灌注改变.将其运用到胰腺疾病的影像学诊断中,有助于提高胰腺疾病的早期发现率以及鉴别诊断的准确性,可以认为胰腺CT灌注成像技术将拥有广阔的应用前景.     

灌注CT在胰头部肿块定性诊断中的应用

随着多层螺旋CT的发展和应用,CT灌注成像应用于临床已成为可能。CT灌注成像是基于CT同层动态增强技术的CT功能成像,它可以提供活体组织的血流动力学参数。目前CT灌注成像在胰腺的应用研究主要集中于正常胰腺组织、胰腺癌及胰腺内分泌肿瘤等。胰腺癌的CT灌注特征是血流量和血容量均低于正常胰腺组织,表现为乏血供肿瘤。胰腺内分泌肿瘤具有较高的血流量和血容量,且血流量的高低与肿瘤的新生血管形成、WHO分级及增生指数具有很强的相关性。但是表面通透性的研究结果在各中心之间差异较大,可能与所用的CT灌注的数学模型不同以及该项技术本身的不完善有关,故CT灌注成像的全面临床应用尚待时日,需要更大样本、更多中心的实验及临床研究。     

超声造影评价肝肿瘤血流灌注及其机理的研究进展

超声声学造影是现代超声领域研究的热点之一,尤其是肝脏肿瘤的研究十分活跃.随着新型相关技术的迅猛发展,超声造影可得到丰富的肝肿瘤供血及血流灌注信息,并出现动态期相性造影增强变化,对肝肿瘤不仅有诊断与鉴别诊断的意义,而且有望成为无创性评价肝肿瘤的微循环及肿瘤新生血管形成过程的重要影像手段.     

贲门周围血管离断术前后肝硬化病人肝脏血流灌注的改变

目的：利用肝脏阻抗血流图探讨肝硬化门静脉高压症病人的肝脏血流灌注改变和贲门周围血管离断术对肝脏血流灌注的影响。方法：选取22例肝硬化门静脉高压症病人，分别在术前1周、术后2周检测肝血流阻抗改变，同时用Doppler检测门静脉血流动力学变化。结果：阻抗血流图表明，和对照XEG相比，门静脉高压症病人的肝动脉、门静脉向肝血流灌注明显下降，总肝灌注量降低；门静脉高压症病人术后门静脉向肝灌注增加，肝动态的向肝灌注无显著改变。Doppler测定表明门静脉高压症病人的门静脉直径增加，血流量增加，但血流速度无显著差别；术后门静脉血流动力学与术前无差别。结论：肝硬化病人肝动脉、门静脉向肝有效血流灌注都降低，肝脏总血流量下降；贲门周围血管离断术增加大部分病人的门静脉向肝血流灌注，但对肝动脉的向肝灌注无显著影响；肝脏阻抗血流图作为反映肝脏动态血流灌注的无创性检查，对于评价肝硬化病人的肝脏血流及评价手术对肝脏血流动力学的影响有一定的价值。     

肝纤维化的影像学评价及进展

目的 综合评述肝纤维化诊断的各种影像检查方法的应用价值及进展。方法 总结超声、CT及磁共振成像在肝纤维化诊断中的表现及最新进展，评价各种方法的特点。结果 影像检查不但能显示肝纤维化及肝硬变的形态学改变，还能了解肝脏血流动力学、水分子弥散、生化代谢等反映功能微观方面的信息，尤其是新技术磁共振弹性成像的出现，对肝纤维化诊断意义重大。结论 影像学检查，尤其是磁共振功能成像技术，在肝纤维化诊断与鉴别、严重度评价等方面作用重要，具有广阔临床应用前景。     

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医学影像学是临床医学科学中发展较快的学科之一。在原有X线造影检查基础上，计算机体层成像(CT)、磁共振成像(MRI)、超声等断面成像技术应用于腹部之后，使腹部疾病的诊断发生了质的变化。近年来，随着影像技术的迅速发展，如多排螺旋CT、高场强MRI、肝脏功能成像、组织(器官)特异性对比剂、彩超、各种介入技术在临床上的应用，使影像技术在腹部疾病中所发挥的作用已经超越了单纯的定位与定性诊断，并在选择治疗方案、制定详细手术计划、疗效评估以及微创治疗等方面，正在发挥着越来越大的作用。因此，作为普外科医生应重视影像技术的临床应用研究，熟知各种影像技术的特点，掌握其适应证，更加充分地利用影像技术为普外科临床服务。     

原发性肝细胞癌多排螺旋CT灌注表现与VEGF,MVD相关性研究进展

原发性肝细胞癌(HCC)是典型的多血管肿瘤,丰富而扭曲的肿瘤血管是肝癌的重要特征,在其发生、发展、浸润及转移的各阶段,肿瘤新生血管均起着重要作用.血管内皮生长因子(VEGF)是重要的促血管生成因子,其表达影响着肿瘤微血管密度(MVD).一种新的CT灌注成像技术被用来研究肿瘤的血流灌注和微血管分布情况.本文就HCC的肿瘤血管生成机制、CT灌注成像的一般原理以及在评价肝癌肿瘤微血管生成指标VEGF,MVD等方面的应用作一综述.     

CT灌注成像在肝癌诊断中的应用

CT灌注成像(CT perfusion imaging,CTPI)定量测定肝脏局部血流可获取相应肝区的灌注指标,如肝血流量、肝血容量、肝动脉灌注指数等.由于不同组织(正常肝、肝硬化、肝细胞癌、转移性肝癌等)的灌注指标存在差异,通过对相关指标进行分析,可鉴别肝脏占位的性质,尤其可诊断微小肝癌.本文介绍了CTPI的原理,肝细胞癌和转移性肝癌CTPI的鉴别要点,CTPI与微血管密度的关系,TACE前后肝癌CTPI的变化,以及CTPI与超声造影诊断敏感性的比较.     

螺旋CT灌注成像对肝癌伴肝硬化患者手术安全性预测的价值

目的:应用螺旋CT灌注成像技术研究肝癌伴肝硬化肝脏的血流动力学改变及特点,探讨CT灌注成像技术对肝癌伴肝硬化患者手术安全性的预测价值.方法:32例肝癌伴肝硬化患者根据CT形态学分级对其肝硬化进行轻、中、重度3级划分并分组,其中轻度组17例、中度组8例、重度组7例,应用CT灌注扫描技术对肝脏血流量(blood flow,BF)、血容量(blood volume,BV)、平均通过时间(mean transit time,MTT)、肝动脉分数(hepatic arterial fraction,HAF)、对比剂到达时间(impulse residue function to,IRF To)、门静脉灌注量(portal vein perfusion,PVP)和肝动脉门静脉灌注比率(HAP/PVP ratio,AN)等进行研究,分析CT灌注参数、肝硬化CT形态学分级及肝功能Child-Pugh分级三者间的相关性.20例行肝癌切除术患者应用判别函数分析CT灌注扫描预测肝癌手术治疗安全性的价值并与Child-Pugh分级进行比较.结果:CT形态学不同分级时BF、BV、IRF To、PVP、MTT、HAF、AN差异有统计学意义并具有相关性(P<0.05);肝功能Child-Pugh分级与CT肝硬化形态学分级呈显著正相关(r＝0.891,P<0.05);20例肝癌患者术前判别函数分析,肝脏灌注参数对手术风险预测的判别符合率为95%,PVP、Child-Pugh分级判别符合率分别为90%、55%.结论:肝脏CT灌注成像不但可以反映肝癌伴肝硬化的肝脏血流灌注特点和对肝硬化程度进行定量分级诊断;而且作为影像学指标评估肝癌患者手术安全性优于Child-Pugh分级.     

区域血流灌注与乳腺癌生物学行为的关系

目的探讨区域血流灌注与乳腺癌的生物学行为的关系,评价区域血流灌注作为一种在新辅助化疗前判断乳腺癌生物学行为的非侵入性指标的价值.方法通过多层螺旋CT灌注成像技术获得乳腺癌区域血流灌注的伪彩色功能图,并定量检测乳腺癌中心、边缘及正常乳腺区域血流灌注指标：肿瘤组织的血流量（BF）、血容量（BV）和表面渗透性（PS）.结果乳腺癌中心区域和边缘区域的血流灌注高于正常乳腺区域,肿瘤边缘区域血流灌注高于肿瘤中心区域;肿瘤中心区域BF的高低与肿瘤大小有关;在肿瘤边缘区域,BF的高低与肿瘤大小、病理分期、组织学类型及PR状态有关,PS与肿瘤的组织学分级有关.结论区域血流灌注高低与肿瘤生物学特点有关,乳腺癌区域血流灌注可作为新辅助化疗前判断肿瘤生物学行为的有效手段.     

Imaging after brain injury

Head injury remains an important cause of death and disabilityin young adults. This review will discuss the role of structuralimaging using computed tomography (CT) and magnetic resonanceimaging (MRI) and physiological imaging using CT perfusion,¹³¹Xe CT, MRI and spectroscopy (MRS), single photon emissioncomputed tomography, and positron emission tomography (PET)in the assessment, management, and prediction of outcome afterhead injury. CT allows rapid assessment of brain pathology whichensures patients who require urgent surgical intervention receiveappropriate care. Although MRI provides greater spatial resolution,particularly within the posterior fossa and deep white matter,a complete assessment of the burden of injury requires imagingof cerebral physiology. Physiological imaging techniques canonly provide ‘snap shots’ of physiology within theinjured brain, but they can be repeated, and such data can beused to assess the impact of therapeutic interventions. Perfusionimaging based on CT techniques (xenon CT and CT perfusion) canbe implemented easily in most hospital centres, and providequantitative perfusion data in addition to structural images.PET imaging provides unparalleled insights into cerebral physiologyand pathophysiology, but is not widely available and is primarilya research tool. MR technology continues to develop and is becominggenerally available. Using a complex variety of sequences, MRcan provide data concerning both structural and physiologicalderangements. Future developments with such imaging techniquesshould improve understanding of the pathophysiology of braininjury and provide data that should improve management and predictionof functional outcome.     

脂肪肝影像学评价的研究进展

目的评价影像学技术在肝脂肪变性的定性及定量诊断中的价值。方法对比超声、CT及MRI对肝脂肪变性的定性及定量诊断的临床应用现况，总结它们各自的进展情况及其优、缺点。结果超声可对肝脂肪变性的定性及定量诊断进行初步的筛选和估计，CT对肝脂肪变性的定量诊断更为可靠，MRI则具有更高的灵敏度和特异性。结论影像学在肝脂肪变性的定性及定量诊断中具有重要的临床价值，特别是MRI波谱成像及双梯度回波成像可对肝脂肪变性作出准确的定量诊断。     

Imaging diagnosis of esophageal carcinoma by computed tomography and magnetic resonance imaging

The staging diagnosis of esophageal carcinoma is important to determine therapeutic modalities and to predict prognosis. The current status of imaging diagnosis of tumor invasion to the adjacent organs and lymph node metastasis is described. The diagnostic criteria used to determine tumor invasion to the adjacent or gans by computed tomography (CT) and magnetic resonance imaging(MRI) are displacement and compression deformity of the tracheobronchial tree and obliteration of the periaortic fat plane over more than 90 degrees of the aortic circumference. Detection of the fat plane between the esophagus and the aorta supported by density profile analyzing software on CT may enable the diagnosis of invasion. Cine-MRI imaging is also useful to obtain dynamic information on the tumor and aorta. Tumor invasion to the aortic wall can be excluded when a low-intensity stripe is recognized between the tumor and the aortic wall. Although the criterion for lymph node metastasis on CT is 10 mm or more in long transverse diameter, the diagnostic accuracy is poor. The accuracy improves when imaging patterns such as heterogeneous internal structures in the enhanced lymph nodes and/or hyperenhancement in the lymph nodes in the early phase by dynamic study are added to the diagnostic criteria. However, small metastatic lymph node remain undetected and it is difficult to diagnose negative lymph node metastasis properly on CT and MRI. It is important to have full knowledge of the advantages and limitations of each imaging modality and to obtain objective information form them.     

磁共振功能成像鉴别胰腺癌与肿块型慢性胰腺炎的价值

目的总结各种磁共振(MR)功能成像的原理及在胰腺癌及肿块型慢性胰腺炎诊断中的应用价值。方法回顾分析国内、外近年来关于MR波谱成像、MR弥散成像及MR灌注成像在胰腺癌及慢性胰腺炎诊断和鉴别诊断中应用的文献。结果胰腺癌与慢性胰腺炎在分子扩散、生化代谢、组织灌注等方面存在差异,MR功能成像方法能反映这些差异而用于鉴别诊断。结论MR功能成像作为一种非侵入性的影像检查方法,能够提供鉴别胰腺癌与肿块型慢性胰腺炎有价值的信息。     

Imaging of multiple myeloma: Current concepts

Medical imaging is of crucial importance for diagnosis and initial staging as well as for differentiation of multiple myeloma (MM) from other monoclonal plasma cell diseases. Conventional radiography represents the reference standard for diagnosis of MM due to its wide availability and low costs despite its known limitations such as low sensitivity, limited specificity and its inability to detect extraosseous lesions. Besides conventional radiography, newer cross-sectional imaging modalities such as whole-body low-dose computed tomography (CT), whole-body magnetic resonance imaging (MRI) and ¹⁸F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/CT are available for the diagnosis of osseous and extraosseous manifestations of MM. Whole-body low-dose CT is used increasingly, replacing conventional radiography at selected centers, due to its higher sensitivity for the detection of osseous lesions and its ability to diagnose extraosseous lesions. The highest sensitivity for both detection of bone marrow disease and extraosseous lesions can be achieved with whole-body MRI and ¹⁸F-FDG PET/CT. According to current evidence, MRI is the most sensitive method for initial staging while ¹⁸F-FDG PET/CT allows monitoring of treatment of MM. There is an evolving role for assessment of treatment response using newer MR imaging techniques. Future studies are needed to further define the exact role of the different imaging modalities for individual risk stratification and therapy monitoring.     

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??Application of CT and MRI in the diagnosis of retroperitoneal tumor YANG Li, XING Ning. Department of Radiology, PLA General Hospital, Beijing 100853, China
Corresponding author: YANG Li, E-mail:yangli301@yahoo.com
Abstract Located deeply and having no symptoms in early stage, the retroperitoneal neoplasm can be detected more often on the abdominal study with ultrasound for the routine healthy care. The definition of tumor location and property depends on the cross-imaging, such as CT and MRI imaging. Clinically, the CT is the fist choice modality for its high spatial resolution and more powerful ability with 3D imaging technique. Enhanced CT and CT reconstruction technique are necessary for the definite diagnosis. The characteristics of tumor and tumor adjacent structure are key points for the definition of tumor location, property and discovery of the involving of the vessels and organs.     

基于CT灌注成像的颅内外动脉旁路移植术在治疗缺血性脑血管病中的应用

目的探讨脑cT灌注成像在指导及评价颅内外动脉旁路移植术（颞浅动脉一大脑中动脉搭桥术）治疗缺血性脑血管病中的作用。方法2008年1月～2011年12月,43例有临床缺血表现的单侧颈内动脉闭塞或大脑中动脉闭塞或大脑中动脉高度狭窄,术前进行脑血管造影及脑CT灌注成像,选取感兴趣区（region of interest,ROI）,测量并评估多个ROI区域以下指标的平均值：相对脑血流量（relativecerebralbloodflow,rCBF）、脑血容量（relative cerebral blood volume,rCBV）、平均通过时间（relative mean transmit time,rMTT）及达峰值时间（relative time topeak,rTTP）,结合患者临床表现及脑血流评估结果,选取有手术适应证的患者进行颞浅动脉-大脑中动脉搭桥手术。手术后复查脑血管造影及脑CT灌注成像,测量术后rCBF、rCBV、rMTT、rTTP。术后对患者进行长期随访并应用美国国立卫生研究院卒中量表（National Institute of Health Stroke Scale,NIHSS）对患者手术前后神经功能状态进行评估。结果①43例均顺利进行颞浅动脉-大脑中动脉搭桥术,术后造影42例（97．7％）吻合口通畅,术后NIHSS评分均较术前明显降低（术前3．67±1．02,术后1周3．30±0．89,术后3个月2．88±0．96,术后12个月2．34±1．02,与术前相比,t=2．634,P=0．012,t=5．373,P=0．000,t=7．342,P=0．000）,随访期间未再出现与患侧相关的脑卒中。②43例手术前后脑cT灌注成像结果显示,术前患侧rCBF较健侧明显降低[（31．37±9．29）ml·100g^-1·min^-1 VS．（45．41±6．91）ml·100g^-1·min^-1,t=一7．921,P=0．000],rMTT、rTTP较健侧明显升高[rMTT（11．32±3．19）sVS．（8．43±1．95）S,t=5．754,P=0．000;rTTP（3．71±1．22）sVS．（2．03±0．87）S,t=9．889,P=0．000],rCBV与健侧差异无显著性（P〉0．05）。术后1周患侧rCBF较术前明显升高[术后（44．05±10．24）ml·100g^-1·min^-1,t=-7．273,P=0．000]。rCBV与术前差异无显著性（P〉0．05）,rMTT、rTTP较术前明显降低[rMTT术后（8．16±1．99）s,t=7．743,P=0．000;rTTP术后（1．88±1．29）S,t=7．333,P=0．000]。手术后患侧以上指标与健侧差异均无显著性（P〉0．05）。结论脑CT灌注成像能够良好地评估颈动脉闭塞、大脑中动脉闭塞或严重狭窄患者的脑血流状态,基于脑cT灌注成像结果筛选脑血流动力学不稳定患者进行颞浅动脉一大脑中动脉搭桥术,可以改善此类患者的脑血流、临床症状。     

Imaging techniques in breast cancer

Imaging plays a critical role in the diagnosis and management of breast cancer. Two-view mammography and ultrasound form the mainstay of breast imaging and are essential components of the triple assessment. Digital mammography is rapidly replacing analogue mammography, and recent advances such as digital tomosynthesis add a third dimension to conventional 2D mammographic images. The versatility of ultrasound allows assessment of the breast and axilla as well as accurately targeted interventions, from the simple diagnostic core biopsy to preoperative tumour localization. It also guides large volume biopsies and excision of certain benign lesions, which in some cases can obviate surgical excision. Newer ultrasound techniques being applied to the breast and axilla include elastography and the use of intradermal microbubbles to guide the radiologist to the sentinel axillary node. Breast MRI is a powerful modality in assessing breast cancer. It can provide accurate information on size and multifocality of lesions, particularly those that are mammographically challenging such as lobular cancers, and it is also used to assess response to neoadjuvant chemotherapy and guide surgical management. CT scans, and in selected cases Positron Emission Tomography, play important roles in the assessment of metastatic disease.