CT灌注成像专题知识.pptx

反应组织血管化程度及血流灌注情况，取得血液动力学方面信息。方法：快速造影剂团注后(5ml/s以上)，在首次经过受检组织过程中对某一选定层面进行快速动态扫描，取得一系列动态图像，分析造影剂经过每个像素所对应体素密度差异，从而得到反应血流灌注情况参数。CTCT灌注成像灌注成像灌注成像灌注成像(Perfusion)(Perfusion)CT灌注成像专题知识第1页 脑梗塞 肝、肾血流灌注及肿瘤诊疗 肾移植血流灌注评价，了解移植血管情况电子束CT灌注可了解心脏灌注，有利于缺血性心肌病早期诊疗CTCT Perfusion Perfusion应用应用应用应用CT灌注成像专题知识第2页 由脑局部缺血而妨碍血液扩散是造成中风，占脑中风70%。用血纤维蛋白可溶解闭塞血管。发生中风后，有效治疗时间为3小时左右。要尽快了解病情类型、发病时间和局部缺血程度。在这段时间内常规CT检验较难发觉，而灌注CT可应用于急性中风检验。CT CT 灌注灌注灌注灌注CT灌注成像专题知识第3页前动脉供血区中动脉供血区后动脉供血区外则内侧底面脑动脉系统脑动脉系统脑动脉系统脑动脉系统CT灌注成像专题知识第4页脑动脉系统脑动脉系统脑动脉系统脑动脉系统CT灌注成像专题知识第5页 在快速注射造影剂后，计算和脑扩散相关参数，从不一样侧面提供中风灌注分布情况：脑血液流量Cerebral Blood Flow,CBF 脑血液容量Cerebral Blood Volume,CBV 造影剂到达各点最大值时间Time Peak，TP 平均经过时间Mean transit time，MTT经过 CBV 与 MTT 可取得 CBFCT PerfusionCT PerfusionCT灌注成像专题知识第6页 常规CT经过组织对X线不一样衰减来显示图像 CTA经过造影剂在血管内流动来显示血管结构 灌注CT利用血液流动相关参数CBF信号强示流速大；造影剂抵达高峰时间分布图TP，愈大意味着造影抵达晚。CBF直接把它和向脑组织提供氧总量联络起来，同时也与血液动力学方面相关。CT PerfusionCT PerfusionCT灌注成像专题知识第7页紫色区域为血流量少,大脑急性中风区域红色区域血流量大CBFCBFCT灌注成像专题知识第8页71岁妇女在症状开始90分钟后进行检验。CT平扫示无反常情况，但CBF示脑左侧(中脑和左半动脉供血)大部分，(前脑动脉)提供地域严重局部缺血，示头颅内颈动脉双枝闭塞。CT PerfusionCT PerfusionCT灌注成像专题知识第9页左半脑症状出现60分钟后，CT平扫无脑异常血液流动，(b)示左侧半脑广泛性和右前部局部缺血。原因：左颈内动脉闭塞。CT灌注成像专题知识第10页CBF CBV Time-to-peak image男44岁右脑中风约2小时，CBF在脑岛脑皮层和豆状核后部，示严重扩散障碍(靠近零)。与左边半球比较，中脑动脉血液供给相当少。CBV显示一样情况，但在右侧MCA其它地方血液容量靠近正常。与左边区域比较，抵达顶点时间图在延长(造影剂延迟抵达)。MCA MI段栓塞和小脑膜血液供给良好，CT灌注成像专题知识第11页CBF Time-to-peak image 3天后 CT上述病例进行动脉血纤维蛋白溶解处理，治疗后一天，用扩散CT成像显示了治疗效果，3天以后CT平扫，示梗塞形成，关键区域与CBF和CBV图像相同。CT灌注成像专题知识第12页 在梗塞关键区域范围确定方面，CT灌注能提供主要信息，可绘局部缺血轮廓，用高密度来显示。用于识别梗塞灶关键和周围梗塞局部缺血(阴影)，为外科提供治疗方法。通常CBV梗塞灶小于CBF和TP，MRI也如此，普通认为CBV提供信息较正确。早期CBV降低 与随即梗塞形成程度较靠近。CT PerfusionCT Perfusion应用应用应用应用CT灌注成像专题知识第13页 与CBV(b)相比CBF(a)、TP(c)在MCA中局部缺血间不匹配。在脑岛脑皮层背部(箭)有一梗塞灶。再通治疗法后二十四小时(d)在MCA一样位置示受限梗塞区。CT灌注成像专题知识第14页 71-year-old female patient with right-sided hemiplegia(偏瘫)and global aphasia(失语).Plain CT(90 minutes later)reveals no early signs of an ischemia(局部缺血).The parameter images display the entire extent of the ischemia with a high-grade reduction of CBF and CBV,a lacking detection of the contrast bolus in the time-to-peak image.The infarction(梗 塞)includes the region of the anterior cerebral artery and large portions of the region supplied by the middle cerebral artery,both features indicative of an occlusion of the intracranial carotid bifurcation.Case 1Case 1CT灌注成像专题知识第15页CT灌注成像专题知识第16页Patient(male 44)with a right-sided ischemia in the region of the middle cerebral artery(MCA)which began 160 minutes ago.Typical findings of a high-grade disturbance in perfusion in the insular cortex and the posterior portion of the lentiform nucleus with a reduction in CBF and CBV as a result of an embolic occlusion in the distal M1 segment.The other regions supplied by the MCA demonstrated good leptomeningeal collateral blood supply which only showed moderately reduced CBF and CBV values,as well as a prolongation of the time-to-peak.Case 2Case 2CT灌注成像专题知识第17页In the calculation of relative perfusion indices from CBF values in ischemic areas and in mirrorred ROIs within the unaffected hemisphere proved to be a valuable method for the prognostic evaluation of a region with reduced perfusion.The core of the infarct and the ischemic marginal zones demonstrate clearly different CBF perfusion indices(green-marked ROI=0.17 versus red-marked ROI=0.69).CT灌注成像专题知识第18页The findings of perfusion CT could be verified by DSA with regard to the type of occlusion and the condition of the collateral blood supply.The follow-up CT after a successful intra-arterial fibrinolysis shows the infarct in dimensions comparable to the infarct core seen with perfusion CT.CT灌注成像专题知识第19页70 minutes after the occurrence of the infarction,the CBF image revealed a highgrade ischemia in the frontal region of the supply area of the MCA and in the lentiform nucleus(Fig.3a)with a perfusion index in the greenmarked ROI of 0.07(Fig.3b).As a result of the good collateral flow,the disturbance in perfusion in the remaining region of the MCA,with a perfusion index of 0.82,is not seen to be very extensive(red-marked ROI in Fig.3b).36-year-old male patient with an embolic occlusion in the M1 segment of the left MCA and a simultaneous occlusion of the left internal carotid artery as a result of dissection.Case 3Case 3CT灌注成像专题知识第20页Because of the partially high-grade ischemia on the one hand and the excellent collateral blood supply of the marginal region on the other,fibrinolysis was not performed in spite of the short time interval.As expected,the follow-up CT revealed the development of an infarction in the area which had primarily demonstrated a high-grade ischemia.CT灌注成像专题知识第21页 灌注CT与颅脑CT扫描和颅脑CT血管造影术结合为脑梗塞早期检验提供了一个有用工具。常规CT可检验梗塞区域形成 灌注CT可决定局部缺血区域，提供了局部缺血组织位置和潜在病变区域 CT血管造影术为诊疗提供了对应病灶区域形态。为临床工作人员决定深入治疗方案提供了主要信息。CT灌注成像专题知识第22页CT PerfusionCT Perfusion前景前景前景前景 当前认为中风处理最正确时间在60分钟。经过对造影剂注入位置与方式研究，灌注CT在不到15分钟中完成中风评价过程。CT灌注成像专题知识第23页 In the course of an investigation performed on 33 patients,an attempt was made to carry out a quantitative evaluation of the severity of the ischemia with the aid of an ROI-evaluation of the CBF images.the calculation of relative perfusion indices from CBF values in ischemic areas and in mirrorred ROIs within the unaffected hemisphere proved to be a valuable method for the prognostic evaluation of a region with reduced perfusion.CT灌注成像专题知识第24页Ischemias with a mild to moderate degree of severity(CBF perfusion index:0.35-0.9)progressed well under fibrinolytic therapy.Even in ischemic regions with a CBF index of 0.35,intra-arterial fibrinolysis could prevent the development of an infarct in more than half of the cases,as long as the index did not fall below a critical value of 0.2.Otherwise,as could be verified with follow-up investigations carried out with computed tomography and magnetic resonance tomography,ischemic necroses were seen to develop without exception.CT灌注成像专题知识第25页 In this way,it was possible to make a differentiation between the infarct core which can no longer be influenced therapeutically and those ischemic margins where therapeutic efforts with perfusion-improving measures may be attempted in order to treat the patient successfully.CT灌注成像专题知识第26页