320排动态容积CT全脑灌注成像技术在脑梗死中的临床应用

目的:探讨320排动态容积CT全脑灌注成像技术在脑梗死诊断中的优势及临床应用价值。方法:对42例脑梗死患者行CT全脑灌注成像,一次对比剂注射得到平扫容积图像、CT血管成像图像及全脑灌注图像,综合运用这三种检查方法全面评估脑梗死。结果:42例脑梗死患者共发现18例存在缺血半暗带(IP),其中8例超急性期6例存在IP,19例急性期8例存在IP,15例亚急性期4例存在IP。42例梗死核心区与健侧对应区比较,脑血容量(CBV)、血流量(CBF)、平均通过时间(MTT)及达峰时间(TTP)值差异均具统计学意义(P<0.05)。18例IP区与梗死核心区比较,CBV、CBF、MTT及TTP值差异均具统计学意义(P<0.05),与健侧对应区比较,CBV值差异无统计学意义(P>0.05)。结论:急性期及亚急性期脑梗死仍可能存在IP。应用320排容积CT全脑灌注成像,对脑梗死患者可明确其责任血管的狭窄部位及程度,了解病变范围及有无IP存在,实现对脑梗死的全面评估。     

急性脑缺血CT灌注成像各参数动态变化的实验研究

目的 :采用自体血栓栓塞模型研究CT灌注成像各参数在脑缺血 12h内的动态变化以及计算各参数的半暗带阈值。方法 :5只新西兰大白兔行自体血栓栓塞制成局灶性脑缺血模型。采用GELightspeed 16MSCT ,在基础灌注后于栓塞后 2 0min扫描一次 ,1～ 6h内每隔 1h扫描一次 ,6～ 12h内每隔 2h扫描一次。CT灌注软件可以给出每个时间点的各参数图。在完成缺血后 12hCT灌注扫描后 ,断头取脑 ,进行TTC染色 ,并根据CT灌注各参数图和TTC的染色结果将梗塞侧分为中心梗塞区 ,半暗带区和相对正常区三部分。结果 :所有参数的动态变化可分为三个阶段 :①梗塞后 2h内 :CBV在中心梗塞区明显下降 ,在半暗带区轻度下降或正常 ,在相对正常区轻度上升 ,CBF在三个区域均明显下降 ,MTT和TTP均明显延长 ;②梗塞后 2～ 5h :所有参数均在一定水平上轻度波动 ;③梗塞后 5～ 12h :在中心梗塞区和半暗带区CBV和CBF下降 ,MTT和TTP延长和轻度缩短 ,而在相对正常区CBV和CBF明显上升 ,MTT和TTP明显缩短。在缺血 2 0min时 ,若CBV % <6 6 .5 7% ,CBF % <39.2 2 % ,MTT % >2 .6 3或TTP % >1.97,缺血组织就发生不可逆损伤。结论 :实验证明CT灌注成像能够准确地显示脑缺血的部位和范围 ,也能在一定程度上反映脑缺血的病理生理改变。CT灌注检查能够指导     

CT灌注成像与MR灌注成像诊断急性缺血性脑卒中的对比研究

目的探讨CT灌注成像(CTPI)与磁共振灌注成像(PWI)对急性缺血性脑卒中(AIS)的诊断效果。方法前瞻性的选取2019年1月～2019年12月我院收治的62例AIS患者作为观察对象,均行CTPI、PWI检查,观察CTPI、PWI影像学特征,记录脑损伤程度,并分析CTPI、PWI灌注参数及患者预后。结果 CTPI影像学表现为梗死中心CBF降低、TTP则不同程度的延迟/消失,PWI影像学表现为梗死中心CBV降低、MTT延长。在脑实质损害程度上,CTPI、PWI检查的一致性高(Kappa=0.874)。灌注参数比较,CTPI、PWI梗死区、半暗带区、健侧CBF、CBV、TTP、MTT差异显著(F=119.549、293.514、63.748、99.240、113.362、193.615、61.965、88.068,P0.05);且CTPI、PWI梗死区CBF、CBV、MTT均显著低于半暗带区、健侧(P均0.05),而TTP显著高于半暗带区、健侧(P均0.05);CTPI、PWI在各区域灌注参数比较差异均无统计学意义(P0.05),CTPI的操作时间显著低于PWI(t=12.251,P0.05)。结论 CTPI、PWI在AIS脑损伤程度的诊断效果相当,且梗死区、半暗带区及健侧的灌注参数变化相似,虽然CTPI耗时较少,但临床选择何种方式仍需视实际情况。     

双低剂量320排 CT 全脑灌注技术在急性期脑缺血中的应用价值

目的：探讨采用“双低剂量”320排 CT 全脑灌注成像联合 CTA 在急性脑缺血中的可行性及实用价值。方法采用“双低方案”对40例拟诊为急性脑缺血患者行320排 CT 全脑灌注成像联合 CTA 一站式检查。利用软件包处理得到 CTA、4D-CTA、4D-perfusion、Fusion 图像,40例患者均经3.0T MR 行 DWI 作为对照。分析评价 CTA 图像质量、血管狭窄程度及缺血病变位置。结果有脑动脉狭窄或闭塞的患者33例,其中8例经 DSA 证实。CTA 质量达优率为82.5%。CT 灌注成像(CTP)发现297处灌注异常区,其中202处病灶 DWI 证实为脑梗死区,95处 DWI 未见异常：49处 CTP 表现为延迟时间(DLY)、达峰时间(TTP)升高,脑血流量(CBF)、脑血容量(CBV)轻度降低;21处 DLY、TTP 升高,CBF、CBV 正常;25处 DLY、TTP 升高,CBF、CBV 轻度升高。结论“双低剂量”320排 CT 脑灌注联合 CTA 是具有可行性和实用性的,可以准确观察颅内血管形态结构及脑组织梗死前期缺血的状态。     

慢性大动脉狭窄或闭塞性分水岭脑梗死的CT灌注分析

目的 利用CT灌注技术分析慢性大动脉狭窄或闭塞性分水岭脑梗死的血流灌注特征.资料与方法 搜集具有完整临床资料的单侧慢性大脑中动脉或颈内动脉重度狭窄或闭塞所致分水岭脑梗死12例,均行CT灌注及数字减影血管造影(DSA)检查.结果 分水岭脑梗死的CT灌注特征是脑血容量(CBV)及脑血流量(CBF)降低、平均通过时间(MTT)及峰值时间(TTP)延长;分水岭周围缺血区的CT灌注特征是CBF降低、MTT及TTP延长,CBV无明显变化.结论 在慢性大脑中动脉或颈内动脉重度狭窄或闭塞的基础上所致分水岭脑梗死灶周围往往伴有大面积的慢性低灌注脑缺血区,低灌注是分水岭脑梗死的重要促发因素.     

脑CT灌注图像匹配技术在缺血性卒中的应用研究

目的探讨CT灌注参数图像标准化匹配技术对梗死后脑组织的缺血状态及确定客观半暗带的评估作用。方法对缺血性卒中患者40例行常规CT灌注检查,重建数据后根据脑血容量(cerebral blood vo lume,CBV)、脑血流量(cerebral blood flow,CBF)、达峰时间(time to peak,TTP)参数分别确定彻底坏死区(non variable tissue,NVT)、严重缺血区(tissue at risk,TAR)、相对缺血区(relative ischemic tissue,RIT)阈值及在脑组织的绝对面积大小,并将3个区域CBF、CBV、TTP参数进行图像匹配,对匹配结果进行分析。结果坏死边缘、严重缺血区、相对缺血区边缘阈值分别为CBV=1.7 mL/100 g、CBF=30.0 mL/(100 g·min)、TTP=9.5 s。图像匹配后可清楚分辨出急性期缺血区的坏死区以及严重缺血区、相对缺血区构成的缺血半暗带并可进行量化面积。匹配后复合性单病灶常见RIT>NVT>TAR、NVT>TAR>RIT,皮质下单病灶组RIT>NVT>TAR或NVT>RIT>TAR,多发梗死病灶组RIT>NVT>TAR、NVT>TAR>RIT。结论利用图像标准化匹配方法可以通过CBV、CBF、TTP参数量化评估病灶的NVT、TAR和RIT区域,直观显示缺血半暗带面积,为临床治疗缺血性卒中提供个体化影像评估技术。     

64层螺旋CT脑灌注成像评价急性脑梗死溶栓前后脑血流动力学改变

目的探讨64层螺旋CT脑灌注成像(CTP)在评价急性脑梗死溶栓疗效中的应用价值。资料与方法20例急性脑梗死患者于发病3~10h行常规CT平扫和CTP检查,其中16例行静脉溶栓、4例行动脉溶栓治疗。溶栓后2~7天复查CT平扫和CTP。对溶栓治疗前后病变区的脑血流量(CBF)、脑血容量(CBV)和达峰时间(TTP)进行定性和定量比较分析。结果20例中5例头颅CT平扫发现早期脑梗死征象,15例常规CT平扫未发现异常,CTP均发现与临床症状对应的脑灌注异常区,表现为CBF、CBV降低,TTP延迟。溶栓后15例脑灌注异常范围缩小,CBF和CBV增加,TTP缩短;3例脑灌注异常区范围扩大,CBF、CBV进一步降低,TTP延迟更加显著;2例出现局部过度灌注。统计学分析结果显示溶栓治疗后多数患者脑灌注情况明显改善,缺血边缘区CBF和TTP与溶栓前差异有统计学意义(P<0.05),缺血中心区CBF和CBV与溶栓前差异无统计学意义(P>0.05)。结论脑CTP检查能够观察溶栓治疗前后脑血流动力学指标的变化,为评价急性脑梗死患者的溶栓疗效提供重要依据。     

16层螺旋CT灌注成像诊断超急性期脑梗死的价值

目的 探讨16层螺旋CT灌注成像对超急性期脑梗死的诊断价值.方法 对20例临床怀疑为超急性期脑梗死患者在发病后6 h内行16层螺旋CT平扫及灌注成像,观察CT平扫表现及灌注图像的Rcbv、Rcbf、MTT及TTP等参数灌注图,所有病例均在发病后1周复查CT平扫.结果 5例CT平扫发现可疑脑缺血区,15例平扫未发现异常.20例CT灌注图上均发现与临床症状相对应的脑缺血区,15例患者复查头颅CT平扫均发现不同程度的脑梗死,脑梗死区Rcbv、Rcbf明显下降,MTT及TTP明显延长.缺血半暗带区表现为Rcbf下降,MTT及TTP延长而Rcbv正常或轻度升高.结论 16层螺旋CT灌注成像诊断超急性脑梗死,对临床治疗具有重要的指导意义.     

CT脑灌注与血管造影在急性脑梗死中的临床应用

目的:探讨64层螺旋CT脑灌注成像和脑血管造影技术在急性期脑梗死中的应用价值。方法:应用PhilipsBrilliance CT 64,对30例发病12h内急性脑缺血患者行CT平扫、CT脑灌注成像(CTP)和CT血管造影(CTA)检查。分析平扫及灌注成像表现,计算出缺血区脑血流参数,包括:脑血容量图(CBV)、血流量图(CBF)、对比剂平均通过时间(MTT)和对比剂峰值时间(TTP),与对侧相应区灌注参数进行比较,并重建颈段和脑内动脉CTA图像。所有病例在发病后3~14天复查CT平扫。结果:30例患者中16例头颅平扫发现早期脑梗死征象,14例常规平扫未发现异常,而CTP均发现灌注异常区。CTP表现为CBF及CBV减低、MTT及TTP延迟;患侧CBF、MTT、TTP与对侧差异有显著性意义(P<0.01),患侧CBV与对侧差异无显著性意义(P>0.01)。重建CTA图像显示16例一侧颈内动脉狭窄,8例一侧大脑中动脉狭窄(其中1例伴大脑后动脉狭窄、左侧后交通动脉闭塞);4例左侧大脑中动脉闭塞,2例左侧颈内动脉闭塞。结论:CTP能够早期、及时、准确地反映缺血部位及程度,预测半暗带;CTA可以显示病变血管的部位和程度;联合应用两者,对早期诊断急性脑缺血和指导治疗有重要价值。     

CT灌注成像联合CT血管成像对急性缺血性脑卒中的诊断价值

目的 探讨256层CT灌注成像（CTP）联合CT血管成像（CTA）在急性缺血性脑卒中诊断中的价值。方法 选取120例发病时间在12 h内的急性缺血性脑卒中患者作为观察对象,患者均同时行CT平扫、CTP检查及CTA检查,对检查结果进行分析。结果 本组120例患者经CT平扫检查显示58例可见早期低密度病灶,其余62例均未见明显异常;经CTP检查显示59例患者可见缺血半暗带,且比较梗死区与对侧脑血流量（CBF）、脑血容量（CBV）、平均通过时间（MTT）差异均有统计学意义（P<0.05）;对比缺血半暗带区与对侧CBF、MTT差异均有统计学意义（P<0.05）;但缺血半暗带区与对侧CBV比较则差异无统计学意义（P<0.05）;缺血半暗带区与梗死区CBF、CBV、MTT比较差异均有统计学意义（P<0.05）;经CTA检查显示本组120例患者中112例可见颈内动脉（ICA）或大脑中动脉（MCA）存在不同程度的狭窄或闭塞现象。结论 联合应用CTP与CTA检查对急性缺血性脑卒中患者具有较高诊断价值,可推广应用。     

320层容积CT全脑灌注成像技术在缺血性脑血管病中的初步应用

目的：初步探讨320层容积CT全脑灌注对于评估缺血性脑血管病的价值。方法：对8例缺血性脑血管病患者在症状出现至常规CT平扫与全脑灌注成像检查时间在4h-1个月。间隔2-3天后复查的CT和／或MRI影像学资料综合分析。比较CT平扫与脑灌注图像发现缺血灶的敏感性,对比评价4层灌注及全脑灌注,并统计辐射剂量。结果：根据8例患者复查的影像学资料综合分析,共发现22处脑缺血灶;8例患者首次常规Cr平扫仅发现9处低密度区,脑灌注图像中发现11处异常灌注区;11处异常灌注区中表现为CBF与CBV均下降,并MTT延长4处,CBF下降,CBV增高,并MTT延长7处。全脑灌注显示病灶范围优于4层灌注。辐射剂量总剂量为4．6mSy。结论：320层容积Cr灌注成像可以通过一次对比剂注射,获得常规CT扫描、全脑灌注、CTA的数据,可以实现对缺血性脑血管病的全面评估。     

256层螺旋CT全脑灌注联合CTA在急性脑梗死诊断中的价值

目的 探讨256层MSCT全脑CTP与CTA技术相结合在急性脑梗死中的应用价值,并评估脑梗死与供血动脉状况的关系.方法 对21例临床拟诊急性脑梗死患者行常规CT平扫、CTP和CTA检查,重建并分析CT平扫图像、CTP及CTA图像,所有病例在CTP检查后24h内进行MRI＋ DWI检查.结果 21例脑梗死患者CTA发现33条动脉不同程度狭窄及闭塞,其中包括轻度狭窄4例,中度狭窄13例,重度狭窄7例,闭塞9例.21例患者CTP发现32处梗死灶,脑梗死中心区及周边区rCBF下降、TTP延长的差异在统计学上有显著性意义.结论 256层螺旋CT全脑CTP联合CTA扫描方法简便,可对缺血后脑组织供血动脉状况及血流动力学改变进行有效评价.     

Utility of CT perfusion with 64-row multi-detector CT for acute ischemic brain stroke

We investigated the utility of computed tomographic (CT) perfusion (CTP) with 64-row multi-detector row CT (MDCT) to diagnose acute infarction and ischemic penumbra. We reviewed 58 clinical cases with acute ischemic stroke with CTP, compared the size of the area with long mean transit time (MTT) to that with abnormal intensity in magnetic resonance (MR) diffusion-weighted imaging (DWI) to diagnose penumbra, and compared the size of the area with reduced cerebral blood volume (CBV) in CTP to that in MR DWI to evaluate sensitivity for infarction. The total sensitivity of MTT to acute ischemic lesions was 81% (47/58). Sensitivity of MTT to segmental lesions was 100% (42/42) and for spot and focal lesions, 31% (5/16). In 13 patients, penumbra was diagnosed as lesions mismatched between MTT in CTP and MR DWI. When we regarded a lesion with decreased CBV as infarction, the sensitivity of CBV to segmental lesions was 85% (11/13), and the sensitivity to small infarction was 14% (4/28). Use of 64-row MDCT improves coverage and radiation exposure in head CTP. The combination of plain CT, CT angiography, and CTP with MDCT can demonstrate all segmental ischemic lesions and most large segmental infarctions, and their combined application is useful in considering indication and contraindication for thrombolysis. The problem of low sensitivity for small lesions remains, and MR DWI may be required to assess small infarctions when findings from combined plain CT, CT angiography, and CTP are negative in patients with suspected acute brain stroke.     

First-pass quantitative CT perfusion identifies thresholds for salvageable penumbra in acute stroke patients treated with intra-arterial therapy

BACKGROUND AND PURPOSE: The purpose of this study was to determine whether, in acute stroke patients treated with intra-arterial (IA) recanalization therapy, CT perfusion (CTP) can distinguish ischemic brain tissue destined to infarct from that which will survive. METHODS: Dynamic CTP was obtained in 14 patients within 8 hours of stroke onset, before IA therapy. Initial quantitative cerebral blood volume (CBV) and flow (CBF) values were visually segmented and normalized in the "infarct core" (region 1: reduced CBV and CBF, infarction on follow-up), "penumbra that infarcts" (region 2: normal CBV, reduced CBF, infarction on follow-up), and "penumbra that recovers" (region 3: normal CBV, reduced CBF, normal on follow-up). Normalization was accomplished by dividing the ischemic region of interest value by that of a corresponding, contralateral, uninvolved region, which resulted in CBV and CBF "ratios." Separate CBV and CBF values were obtained in gray matter (GM) and white matter (WM). RESULTS: Mean CBF ratios for regions 1, 2, and 3 were 0.19 +/- 0.06, 0.34 +/- 0.06, and 0.46 +/- 0.09, respectively (all P < .001). Mean CBV ratios for regions 1, 2, and 3 were similarly distinct (all P < .05). Absolute CBV and CBF values for regions 2 and 3 were not significantly different. All regions with CBF ratio <0.32, CBV ratio <0.68, CBF <12.7 mL/100 g/min, or CBV <2.2 mL/100 g infarcted. No region with CBF ratio >0.44 infarcted. GM versus WM CBF and CBV values were significantly different for region 2 compared with region 3 (P < .05). CONCLUSIONS: In acute stroke patients, quantitative CTP can distinguish ischemic tissue likely to infarct from that likely to survive.     

Effect of the arterial input function on the measured perfusion values and infarct volumetric in acute cerebral ischemia evaluated by perfusion computed tomography

OBJECTIVES: We sought to evaluate the accuracy of the perfusion computed tomography (PCT) deconvolution-based brain perfusion measurements and the lesions' (infarct and penumbra) volumetric with regard to arterial input function (AIF) selection in patients with acute stroke. MATERIALS AND METHODS: Eighteen consecutive patients with symptoms of acute stroke underwent PCT at admission. Follow-up magnetic resonance imaging was obtained in all patients after 3.6 +/- 1.7 days (range, 1.5-6 days). PCT maps were generated focusing on the anterior cerebral artery (ACA) and branches of the middle cerebral artery (MCA) ipsilateral and contralateral to the ischemic lesion as AIFs. Infarct, penumbra, and total ischemic lesion were delineated on cerebral blood flow (CBF) maps. CBF, cerebral blood volume (CBV), and mean transit time (MTT) were calculated in the ischemic regions as provided by the 3 different AIFs, the normality test was applied for the obtained parameters, and the values were correlated (Pearson's correlation coefficient). Volumes of the ischemic regions (as obtained by the different AIFs) also were correlated and compared (paired t test) to the follow-up infarct volume. RESULTS: The CBF and CBV values obtained by the different AIFs in the infarct, penumbra, and total ischemic lesion were significantly correlated (r=0.94-0.96, P相似文献   

Whole brain quantitative CBF, CBV, and MTT measurements using MRI bolus tracking: implementation and application to data acquired from hyperacute stroke patients

A robust whole brain magnetic resonance (MR) bolus tracking technique based on indicator dilution theory, which could quantitatively calculate cerebral blood flow (CBF), cerebral blood volume (CBV), and mean transit time (MTT) on a regional basis, was developed and tested. T2*-weighted gradient-echo echoplanar imaging (EPI) volumes were acquired on 40 hyperacute stroke patients after gadolinium diethylene triamine pentaacetic acid (Gd-DTPA) bolus injection. The thalamus, white matter (WM), infarcted area, penumbra, and mirror infarcted and penumbra regions were analyzed. The calculation of the arterial input function (AIF) needed for absolute quantification of CBF, CBV, and MTT was shown to be user independent. The CBF values (ml/min/100 g units) and CBV values (% units, in parentheses) for the thalamus, WM, infarct, mirror infarct, penumbra, and mirror penumbra (averaged over all patients) were 69.8 +/- 22.2 (9.0 +/- 3.0 SD); 28.1 +/- 6.9 (3.9 +/- 1.2); 34.4 +/- 22.4 (7.1 +/- 2.7); 60.3 +/- 20.7 (8.2 +/- 2.3); 50.2 +/- 17.5 (10.4 +/- 2.4); and 64.2 +/- 17.0 (9.5 +/- 2.3), respectively, and the corresponding MTT values (in seconds) were 8.0 +/- 2.1; 8.6 +/- 3.0; 16.1 +/- 8.9; 8.6 +/- 2.9; 13.3 +/- 3.5; and 9.4 +/- 3.2. The infarct and penumbra CBV values were not significantly different from their corresponding mirror values, whereas the CBF and MTT values were (P < 0.01). Quantitative measurements of CBF, CBV, and MTT were calculated on a regional basis on data acquired from hyperacute stroke patients, and the CBF and MTT values showed greater sensitivity to areas with perfusion defects than the CBV values. J. Magn. Reson. Imaging 2000;12:400-410.     

Evaluation of cerebral perfusion parameters measured by perfusion CT in chronic cerebral ischemia: comparison with xenon CT

PURPOSE: The purpose of this work was to evaluate the usefulness of perfusion CT in the evaluation of patients with chronic cerebral ischemia by comparing it with xenon CT (Xe-CT). METHOD: Cerebral blood flow (CBF) of perfusion CT (CBFper) and time to peak (TTP) were compared with the CBF of Xe-CT (CBFxe) in 18 patients. Cerebral blood volume (CBV) was compared with cerebral vascular reserve (CVR) in 10 of 18 patients who underwent pre- and postacetazolamide Xe-CT. RESULTS: CBFper and TTP demonstrated a high correlation with CBFxe in relative values by side-to-side comparisons (r = 0.743, p < 0.0001 and r = -0.760, p < 0.0001, respectively). There was a negative correlation between relative CBV and relative CVR (r = -0.637, p = 0.0025). Visually, territories with delayed TTP corresponded well to those of decreased CBFxe, but these territories tended to be larger in TTP maps. CONCLUSION: Perfusion CT is a useful tool to evaluate chronic hemodynamic disturbance and can be an alternative method for those using acetazolamide challenge.