脑供血动脉狭窄支架术前后脑CT灌注评价

目的:探讨症状性脑供血动脉狭窄内支架成形术前术后脑CT灌注成像的各项参数变化及其与临床症状转归的相关性.方法:本研究纳入10例患者,全部经全脑DSA证实有单侧脑供血动脉狭窄(≥65%),所有患者于血管内支架术前及术后48h内行脑CT灌注成像检查,测量CBV、CBF、TTP并同时予以NIHSS评分.结果:10例患者行脑供血动脉狭窄内支架成形术前术后48h内的大脑中动脉供血区域的脑CT灌注成像的各项参数变化如下:9例患者术后的rTTP较术前明显缩短,1例患者rTTP术后与术前相同(P=0.01<0.05);5例患者术后的rCBV及rCBF较术前均升高,另外有4例患者术后的rCBV及rCBF较术前均降低,1例患者术后的rCBV较术前降低rCBF较术前升高.7例患者术后NIHSS评分降低(P=0.004<0.05).症状性脑供血动脉狭窄内支架成形术前术后脑CT灌注成像参数变化及其与临床症状转归相关系数r=-0.062,P=0.864>0.05.结论:脑CT灌注成像是评估症状性脑供血动脉狭窄内支架成形术后脑灌注改善的可信指标.CTP参数变化与临床症状转归没有相关性.     

4D-CTA联合全脑灌注成像在颅内动脉瘤术后随访中的应用价值

目的 利用4D-CTA联合全脑灌注成像的方法评估颅内动脉瘤术后血管及血流动力学改变.方法 回顾性分析49例颅内动脉瘤性蛛网膜下腔出血(SAH)术后的患者,所有患者均于发生SAH 3 ～ 14天内行全脑灌注成像检查.使用西门子公司SyngoMMWP后处理工作站,用Inspace软件重组4D-CTA图像,以VPCT Neuro软件,生成脑血流量(CBF)、血容量(CBV)、达峰时间(TTP)、延迟时间(TTD)及平均通过时间(MTT)伪彩图.在检查残余动脉瘤的同时判断有无脑血管痉挛及其他血管病变,并用灌注参数评估SAH继发的迟发性脑缺血情况及其他并发症.结果 4D-CTA共检出59个颅内动脉瘤的术后改变.其中动脉瘤夹闭术后50个,栓塞术后9个.1例前交通动脉瘤夹闭术后存在残留动脉瘤.2例患者发现颅内其他部位存在动脉瘤.4D-CTA上18例患者共28条血管出现血管痉挛.共29例患者的伪彩图上出现异常灌注区域,其中23例患者为迟发性缺血,2例患者为血管夹压迫相关脑缺血,4例患者为手术操作损伤相关脑缺血.结论 4D-CTA可清晰显示动脉瘤术后有无瘤体残留、动脉瘤夹及栓塞材料与载瘤血管的关系.4D-CTA联合全脑灌注成像可同时显示宏观上的血管痉挛及灌注上的微循环改变.全脑灌注成像可显示术后多种并发症所导致的血流动力学改变.     

DSA灌注造影在缺血性脑血管病介入检查及治疗中的应用

目的:探讨DSA灌注成像在缺血性脑血管病介入检查及治疗中的应用价值。方法:对4例健康志愿者及50例临床诊断为缺血性脑血管病的患者进行全脑血管造影及DSA灌注造影,对其中10例进行支架成形术的患者术后再次进行DSA脑灌注检查,评价支架成形术后的脑血流改变。结果:4例健康志愿者的DSA脑灌注造影显示实质期脑染色均匀,血供丰富。50例缺血性脑血管病患者的DSA脑灌注造影显示,47例患者实质期脑染色出现不同程度的改变,10例支架成形术后DSA脑灌注造影与术前相比脑实质染色有明显的增强。结论:DSA灌注成像在缺血性脑血管病介入检查及治疗中具有重要的作用,能够总体描绘脑部血供的分布、脑实质的染色及异常改变,客观评价支架置入术对缺血性脑血管病的治疗效果。     

CT灌注成像诊断脑梗死与脑肿瘤

随着多层螺旋CT的发展,CT脑灌注成像技术显示了重要的临床应用价值.本文在介绍CT脑灌注成像原理的基础上,对CT脑灌注在脑梗死及脑肿瘤方面的应用进行了回顾,并在介绍脑缺血CT诊断方案的同时提出了CT脑灌注成像的安全性问题.     

全脑CT灌注成像在烟雾病血管重建术中的应用价值

目的探讨全脑CT灌注成像在烟雾病血管重建术中的应用价值。方法 18例烟雾病患者实施血管重建术前、术后分别行全脑CT灌注成像,对手术前后脑血流量(CBF)、脑血容量(CBV)、平均通过时间(MTT)和达峰时间(TTP)进行定性和定量分析,采用配对t检验比较手术前后CT灌注参数值的差异。结果 18例患者术后CTA均显示搭桥血管通畅。血管重建术后1周手术侧异常灌注明显改善,TTP和MTT较术前减低,CBF和CBV较术前增高,手术前后灌注参数绝对值的差异有统计学意义。结论全脑CT灌注成像能评价烟雾病血管重建术前和术后的脑血流动力学变化,同时还可评估桥血管再通情况,具有较高的临床应用价值。     

IVIM与DSC灌注成像在脑星形细胞瘤分级中的诊断价值

目的：探讨 MR 体素内不相干运动(IVIM)成像与动态磁敏感对比增强(DSC)灌注成像在脑星形细胞瘤分级中的诊断价值。方法对手术病理证实的22例高级别及28例低级别星形细胞瘤患者术前行 MR 常规扫描及 IVIM、DSC 扫描,定量测量2组肿瘤实质区 IVIM 成像参数值,包括标准扩散系数(ADCstandard )、慢扩散系数(D)、快扩散系数(D?)、灌注分数(f)和 DSC 灌注成像参数值,包括相对脑血容量(rCBV)、相对脑血流量(rCBF),采用两独立样本 t 检验分析各参数值在高、低级别脑星形细胞瘤中是否有统计学差异,应用受试者工作特征曲线(ROC)评价单独及联合应用 IVIM 成像和 DSC 灌注成像的诊断效能。结果肿瘤实质区ADCstandard 值、D 值、rCBV 值、rCBF 值在脑星形细胞瘤分级中有明显统计学差异(P <0.01);D?值、f 值在脑星形细胞瘤分级中无统计学差异(P=0.130,P=0.379);各参数值对脑星形细胞瘤分级的 ROC 曲线下面积为：ADCstandard 值0.823,D 值0.854,rCBV 值0.858,rCBF值0.871,D 值与 rCBV 和 rCBF 值联合应用0.952,0.953。结论D 值及 rCBV、rCBF 值可以对脑星形细胞瘤进行分级,联合应用IVIM 成像与 DSC 灌注成像可以提高脑星形细胞瘤分级的准确性。     

非梗死性缺血性脑血管病颅脑CT灌注成像诊断价值的研究

目的：评价脑CT灌注成像对非梗死性缺血性脑血管病的诊断价值。方法：40例脑血管病患者,均行脑CT平扫、脑CT灌注成像、CTA及TCD检查。比较脑CT灌注成像与CTA、TCD对非梗死性脑缺血病变诊断的敏感性。结果：40例患者脑CT灌注成像均发现脑组织异常灌注区域,其中脑梗死前期Ⅰ1期29例,脑梗死前期Ⅰ2期4例,脑梗死前期Ⅱ1期5例,脑梗死前期Ⅱ2期2例;CTA显示颈内动脉、椎-基底动脉及其颅内分支正常25例,异常15例;TCD显示颈内动脉、椎-基底动脉及其颅内分支正常20例,异常20例。对脑梗死前期Ⅰ1期的诊断,脑CT灌注成像与CTA、TCD有显著差异（P〈0.01）,对脑梗死前期Ⅰ2期和脑梗死前期Ⅱ期的诊断,脑CT灌注成像与CTA、TCD无显著差异（P〉0.05）。结论：脑CT灌注成像能够发现常规影像学检查无异常改变的脑血流异常灌注区,为临床早期诊断、预防脑梗死提供祥实、可靠的影像学依据。     

MR灌注加权成像在脑血管性疾病中的应用进展

目前,常见的灌注方法包括单光子发射计算机断层显像术（sPECT）、氙CT（Xe—CT）、正电子发射断层显像术（PET）、CT灌注成像、MR灌注成像等。MR灌注成像是一种无创的检查方法,实现了覆盖全脑扫描,可提供多参数多范围的灌注信息。MR灌注成像有2种方法：一种是使用可自由扩散的水质子作为内源性示踪剂的成像方法,称动脉自旋标记法（arterial spin labeling,ASL）;另一种是团注非扩散顺磁性对比剂的首过成像方法,     

3.0T动态磁敏感对比增强磁共振成像在鉴别脑胶质瘤复发与放射性脑损伤中的价值

目的 探讨3.0T 动态磁敏感对比增强磁共振灌注成像在鉴别脑胶质瘤术后复发与放射性脑损伤方面的应用价值.方法 41例脑胶质瘤术后放疗后患者,肿瘤复发组24例,放射性脑损伤组17例.使用3.0T MR扫描仪行静脉团注Gd-DTPA的DSC灌注检查,分析强化中心区及强化边缘区血流灌注指标:平均rCBVmax比值、平均rCBFmax比值与平均rMTTmax比值.结果 强化中心区域的平均rCBVmax及平均rCBFmax比值分别为5.279±1.588及4.876±1.436,放射性脑损伤组强化中心区域的平均rCBVmax及平均rCBFmax比值分别为2.244±0.698及2.051±0.992,两灌注指标在肿瘤复发和放射性脑损伤2组间差异均具有统计学意义.结论 平均rCBFmax比值与平均rCBVmax比值均可用于脑胶质瘤术后肿瘤复发与放射性脑损伤的鉴别.动态磁敏感对比增强磁共振成像有助于鉴别脑胶质瘤术后复发与放射性脑损伤.     

PC机辅助MR脑灌注成像初步研究

目的:研究PC机辅助MR脑灌注成像软件,探讨其临床应用价值。方法:在PC机上使用MR脑灌注成像软件,对5例健康人和18例脑缺血患者的灌注图像进行后处理,计算出有关脑灌注参数图,包括相对脑血流量(rrCBF)图、相对脑血容量(rrCBV)图、局部灌注达峰时间(TTP)图和团注平均通过时间(bMTT)图。结果:应用MR脑灌注成像软件可以在PC机上实现灌注图像的后处理,脑灌注参数图能够为脑缺血患者提供有价值的脑血液动力学信息,显示灌注异常的范围。结论:PC机辅助MR脑灌注成像软件简单易行,可显示常规MR无法显示的血流动力学异常,对临床和科研具有重要价值。     

Systematic review of CT and MR perfusion imaging for assessment of acute cerebrovascular disease

BACKGROUND AND PURPOSE: Perfusion imaging sequences are an important part of imaging studies designed to provide information to guide therapy for treatment of cerebrovascular disease. The purpose of this study was to perform a meta-analysis of the medical literature on perfusion imaging to determine its role in clinical decision making for patients with acute cerebral ischemia.MATERIALS AND METHODS: We searched MEDLINE by using a strategy that combined terms related to perfusion imaging with terms related to acute cerebral ischemia and brain tumors. We identified 658 perfusion imaging articles and classified them according to the clinical usefulness criteria of Thornbury and Fryback. We found 59 articles with promise of indicating usefulness in clinical decision making. We devised and implemented a clinical decision making scoring scale more appropriate to the topic of acute cerebral ischemia.RESULTS: Several articles provided important insights into the physiologic processes underlying acute cerebral ischemia by correlation of initial perfusion imaging deficits with clinical outcome or ultimate size of the infarct. However, most articles showed relatively low relevance to influencing decisions in implementing treatment.CONCLUSION: Most perfusion imaging articles are oriented toward important topics such as optimization of imaging parameters, determination of ischemia penumbra, and prediction of outcome. However, information as to the role of perfusion imaging in clinical decision making is lacking. Studies are needed to demonstrate that use of perfusion imaging changes outcome of patients with acute cerebral ischemia.

This study is the culmination of work performed in response to a request for applications submitted by the Neuroradiology Education and Research Fund of the American Society of Neuroradiology (ASNR) for a systematic review of the medical literature regarding the usefulness of perfusion imaging in neuroradiology. The authors were charged with the task of examining the evidence for a substantive role for perfusion imaging in evaluation of the brain with a focus on understanding the place of perfusion imaging in medical decision making. We found that most published work has focused on 2 subjects, cerebrovascular disease and brain neoplasms, and 2 techniques, CT perfusion imaging and MR perfusion imaging. This study presents the results of our meta-analysis solely with regard to cerebrovascular disease. The results of the meta-analysis of perfusion imaging in imaging of brain tumors will be provided in a separate report.The goal of the meta-analysis was to determine the extent to which perfusion imaging figures affect clinical decision making and influence patient outcomes. It is important to note that the goal was not to establish whether perfusion imaging yields important information that advances our understanding of the physiologic processes of cerebral infarction or whether perfusion imaging might provide data that could determine likelihood of success of stroke therapy.     

Pulmonary MR angiography and perfusion imaging—A review of methods and applications

The pulmonary vasculature and its role in perfusion and gas exchange is an important consideration in many conditions of the lung and heart. Currently the mainstay of imaging of the vasculature and perfusion of the lungs lies with CT and nuclear medicine perfusion scans, both of which require ionizing radiation exposure. Improvements in MRI techniques have increased the use of MRI in pulmonary vascular imaging. Here we review MRI methods for imaging the pulmonary vasculature and pulmonary perfusion, both using contrast enhanced and non-contrast enhanced methodology.In many centres pulmonary MR angiography and dynamic contrast enhanced perfusion MRI are now well established in the routine workflow of patients particularly with pulmonary hypertension and thromboembolic disease. However, these imaging modalities offer exciting new directions for future research and clinical use in other respiratory diseases where consideration of pulmonary perfusion and gas exchange can provide insight in to pathophysiology.     

乳腺MR灌注时间-信号强度曲线表现及价值研究

目的探讨乳腺MRT2*WI首次通过灌注时间-信号强度曲线(TIC)表现及其在乳腺病变鉴别诊断中的价值。资料与方法对40例乳腺肿瘤患者行乳腺动态增强成像扫描,绘制T2*WI首次通过灌注TIC及T1WI动态增强TIC。采用Fisher’s确切概率法检验,判定良、恶性病灶T1WI动态增强及灌注TIC的差异。结果良、恶性病灶灌注TIC之间差异具有显著性统计学意义(P<0.05=0.000);良、恶性病灶T1WI动态增强TIC之间差异有显著性统计学意义(P<0.05=0.011),但在平台型曲线类型中良恶性病灶有较大重叠。结论乳腺MR灌注TIC在良、恶性病灶具有显著差别,恶性病灶灌注TIC主要表现为信号快速下降后缓慢回升(A型)与快速下降后不回升(B型);良性病灶灌注TIC主要表现为平直型(C型)及缓慢上升后平台型(D型)。灌注TIC与病灶形态学结合可大大提高乳腺疾病诊断的准确性。     

MR灌注成像在脑胶质瘤中的研究进展

MR灌注成像主要通过测量血流动力学参数来反映组织血流灌注及微血管渗透情况。根据其成像原理不同分为动态磁敏感对比增强MRI(DSC-MRI)、动态对比增强MRI(DCE-MRI)和动脉自旋标记(ASL)灌注成像。这些方法各有优缺点,就MR灌注成像的基本原理及其在脑胶质瘤中的研究进展进行综述。     

CT stress myocardial perfusion imaging using multidetector CT--A review

Computed tomography coronary angiography (CTA) accurately detects and excludes coronary artery disease (CAD); however, the physiological significance of coronary artery lesions may be uncertain. CT myocardial perfusion imaging (CTP) acquired during vasodilator stress provides a novel and emerging method for detection of myocardial ischemia. Multiple studies have established the feasibility of CTP and suggested its incremental value when used in combination with CTA in the identification of hemodynamically significant stenoses as compared with CTA alone. Despite these encouraging clinical data, CT perfusion assessment is in its infancy, as further research is required to validate and optimize this new technique. Combined CTA/CTP imaging has significant potential, as it offers the convenience of assessing both coronary anatomy and myocardial perfusion in one single examination at a radiation dose equivalent to contemporary nuclear medicine imaging. In this review, we provide an overview of the fundamentals of CT perfusion imaging, recent advances in scanner types and imaging techniques and protocols, and current literature on the accuracy of CTP, concluding with its future challenges and directions.     

Prognostic value of myocardial perfusion imaging: State of the art and new developments

Although the prognostic value of myocardial perfusion imaging is now well established, new data have continued to expand its role in the management of patients. This review addresses the current state-of-the-art and new developments in the use of myocardial perfusion imaging for determining cardiac risk and integrating such information into patient care.     

双源CT双能量肺灌注成像评估COPD研究进展

慢性阻塞性肺疾病(COPD)是以各种原因引起的肺实质和小气道损伤而导致慢性不可逆的气道阻塞、呼吸阻力增加以及肺功能不全为共同特征的肺疾病。目前肺功能检查、肺核素灌注显像和MR灌注成像评估COPD均不能高分辨力显示肺解剖影像。而双源CT双能量肺实质灌注成像能够显示肺的解剖及灌注功能信息,可对肺气肿的部位与灌注缺损区精确配准,虚拟平扫影像可辨别COPD的类型及肺气肿的数量和大小,这对于COPD早期诊断、治疗及预后评估具有重要意义。就双源CT双能量肺灌注成像技术原理及其在COPD中的研究进展予以综述。     

The expanding role of left ventricular functional assessment using gated myocardial perfusion SPECT: the supporting actor is stealing the scene

Background Gating of single-photon emission computed tomography (SPECT) has significantly improved the reliability and diagnostic accuracy of myocardial perfusion imaging. The functional parameters derived from this technique, mainly left ventricular volumes and ejection fraction, have been demonstrated to be accurate and reproducible. They are able to increase the detection of severe and extensive coronary artery disease and show a significant incremental prognostic power over perfusion abnormalities. Therefore, the importance given to gated SPECT functional data has progressively grown. Discussion This circumstance has further expanded the indications for myocardial perfusion imaging and strengthened its position among the different imaging modalities. Moreover, several studies show that the evaluation of ventricular function may have a leading part in justifying the execution of perfusion scintigraphy in various clinical conditions. Aim Aim of this review is to describe this evolution of gated SPECT functional assessment from a supporting rank with respect to perfusion, to a main actor position in the field of cardiac imaging.     

Viability imaging by cardiac computed tomography

First-pass perfusion and delayed enhancement cardiac imaging have been shown to be feasible by cardiac CT. However, questions remain about its reliability, and ideal scanning parameters have yet to be fully established. In general, scar imaging with cardiac CT typically requires 2 scans, with first-pass perfusion information derived from the same data set used to visualize the coronary arteries. Reduced contrast enhancement on first-pass cardiac CT images represents reduced perfusion. Higher doses of contrast are required to perform viability imaging by cardiac CT. Approximately 10 minutes after contrast administration, viability information is obtained by performing a second (noncontrast) scan. In addition to the concepts of perfusion and viability imaging by cardiac CT, we review parameters such as scan timing, tube settings, contrast delivery, reconstruction, and postprocessing techniques, as well as the associated pitfalls and technical limitations in perfusion and viability imaging by cardiac CT.     

Brain perfusion: computed tomography applications

Within recent years, the broad introduction of fast multi-detector computed tomography (CT) systems and the availability of commercial software for perfusion analysis have made cerebral perfusion imaging with CT a practical technique for the clinical environment. The technique is widely available at low cost, accurate and easy to perform. Perfusion CT is particularly applicable to those clinical circumstances where patients already undergo CT for other reasons, including stroke, head injury, subarachnoid haemorrhage and radiotherapy planning. Future technical developments in multi-slice CT systems may diminish the current limitations of limited spatial coverage and radiation burden. CT perfusion imaging on combined PET-CT systems offers new opportunities to improve the evaluation of patients with cerebral ischaemia or tumours by demonstrating the relationship between cerebral blood flow and metabolism. Yet CT is often not perceived as a technique for imaging cerebral perfusion. This article reviews the use of CT for imaging cerebral perfusion, highlighting its advantages and disadvantages and draws comparisons between perfusion CT and magnetic resonance imaging.