CT灌注成像

CT Perfusion应用
在梗塞核心区域范围确定方面，CT灌注能提供重要 信息，可绘局部缺血轮廓，用高密度来显示。
用于辨认梗塞灶核心和周围梗塞局部缺血(阴影)，为 外科提供治疗方法。
通常CBV的梗塞灶小于CBF和TP，MRI也如此，一 般认为CBV提供的信息较正确。早期CBV减少 与随后 梗塞形成程度较接近。
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.
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).
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24小时 (d)在MCA同样位置 示受限梗塞区。
Case 1 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.
CT灌注成像 (Perfusion)
反映组织的血管化程度及血流灌注情况，获得血 液动力学方面的信息。
方法：快速造影剂团注后(5ml/s以上)，在首次经 过受检组织的过程中对某一选定的层面进行快速动 态扫描，获得一系列动态图像，分析造影剂通过每 个像素所对应的体素密度的差异，从而得到反映血 流灌注情况的参数。
CT Perfusion应用
脑梗塞 肝、肾血流灌注及肿瘤的诊断 肾移植的血流灌注的评价，了解移植血管的情况 电子束CT的灌注可了解心脏灌注，有助于缺血性 心肌病的早期诊断
CT 灌注
由脑局部缺血而阻碍血液扩散是导致中风，占脑 中风70%。用血纤维蛋白可溶解闭塞的血管。
发生中风后，有效治疗的时间为3小时左右。要 尽快了解病情类型、发病时间和局部缺血的程度。
常要规尽C快男T了通解过4病组4情织岁类对型X右、线发不脑病同时衰中间减和来风局显部示约缺图血像2的小程度时。 ，CBF在脑岛的脑皮层和豆状核后部，
要尽快了解病情类型、发病时间和局部缺血的程度。
造影剂示到达严高峰重的时扩间分散布图障TP，碍愈大(意接味着近造影零到达)。晚。与左边半球比较，中脑动脉血液供应
Case 3
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.
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.
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 ).
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 2
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 prolongatiBecause of the partially high-grade ischemia on the one hand and the excellent collateral blood supply of the marginal region on the other,
相当少。CBV显示同样情况，但在右侧MCA其他地方血液容量 fibrinolysis was not performed in spite of the short time interval.
在这段时间内常规CT检查较难发现，而灌注CT 可应用于急性中风检查。
脑动脉系统
前动脉供血区 中动脉供血区
外则
内侧
后动脉供血区 底面
脑动脉系统
CT Perfusion
在快速注射造影剂后，计算和脑的扩散有关的参 数，从不同侧面提供中风的灌注分布情况： 脑血液流量Cerebral Blood Flow, CBF 脑血液容量Cerebral Blood Volume, CBV 造影剂达到各点最大值的时间Time Peak，TP 平均通过时间Mean transit time，MTT 通过 CBV 与 MTT 可获得 CBF
CBF
红色区域血流量大
紫色区域为血流量少, 大脑急性中风区域
CT Perfusion
71岁妇女在症状开始90分钟后进行检查。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) 提供地区严重局部缺血，示头颅内颈动脉的双枝闭塞。
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的局部缺血。 原因：左颈内动脉闭塞。
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 Perfusion
常规CT通过组织对X线不同衰减来显示图像 CTA通过造影剂在血管内流动来显示血管结构 灌注CT利用血液流动有关的参数CBF信号强示流 速大；造影剂到达高峰的时间分布图TP，愈大意味 着造影到达晚。 CBF直接把它和向脑组织提供氧的总量联系起来 ，同时也与血液动力学方面有关。
接近正常。与左边区域比较，达到顶点时间图在延长(造影剂延
迟到达)。MCA MI段栓塞和小脑膜血液供应良好，
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，"核心"区域与CBF和CBV图像相似。
CBF
CBV
Time-to-peak image
3a) with a perfusion index in the greenmarked ROI of 0. 用于辨认梗塞灶核心和周围梗塞局部缺血(阴影)，为外科提供治疗方法。 71岁妇女在症状开始90分钟后进行检查。 CT Perfusion前景 与左边半球比较，中脑动脉血液供应相当少。 肝、肾血流灌注及肿瘤的诊断 CT血管造影术为诊断提供了相应病灶区域的形态。 71-year-old female patient with right-sided hemiplegia(偏瘫) and global aphasia(失语). The follow-up CT after a successful intra-arterial fibrinolysis shows the infarct in dimensions comparable to the infarct core seen with perfusion 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，"核心"区域与 CBF和CBV图像相似。 CT Perfusion应用 71-year-old female patient with right-sided hemiplegia(偏瘫) and global aphasia(失语). CT Perfusion CT Perfusion前景
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.