摘要
目的:应用CT灌注成像(CT perfusion imaging,CTPI)对高血压脑出血急性期及亚急性期血肿周围低灌注组织血流动力学变化进行动态观察,分析是否存在缺血半暗带并探讨其转归。
材料与方法:对27例采用内科保守治疗高血压脑出血病人进行前瞻性研究,分别于急性期及亚急性期行CT平扫及CTPI扫描。测量脑血肿周围组织及对侧镜像区脑血流量(cerebral blood flow,CBF)、脑血容量(cerebral blood volume,CBV)及平均通过时间(mean transit time,MTT)。根据“同侧/对侧”的公式计算相对脑血流量(relative CBF,rCBF)、相对脑血容量(relative CBV,rCBV)。于急性期测量血肿中心层面血肿及周围低灌注区域面积,亚急性期选择与急性期同一层面测量血肿周围强化环所包围的面积。
结果:灌注参数图示急性期血肿及周围组织有明显低灌注梯度存在,血肿周围区组织CBF、CBV均较对侧镜像区降低(Z分别为4.213及4.265,P值均小于0.05),MTT较对侧延长(Z=2.631,P<0.05);亚急性期血肿周围区组织CBF较对侧镜像区降低(Z=4.600,P<0.05),与急性期比较无明显变化(Z=0.024,P>0.05),急性期血肿周围区与亚急性期血肿周围区rCBF比较无显著差异(Z=0.102,P>0.05)。亚急性期血肿周围区组织CBV亦较对侧镜像区降低(Z=3.652,P<0.05),但是与急性期比较CBV有较明显升高(Z=2.21,P<0.05)。急性期血肿中心层面血肿及周围低灌注区面积与亚急性期同一层面血肿周围强化环所包围之面积比较无显著差异(Z=1.590,P>0.05)。
结论:动态CT灌注成像可以准确地反映高血压脑出血急性期及亚急性期血肿周围组织的低灌注状态;高血压脑出血病人血肿周围组织于急性期存在低灌注状态,这种低灌注状态并不是缺血半暗带的表现,经保守治疗后这种低灌注状态在亚急性期并不会有明显改善,且处于低灌注状态的组织最终很可能会坏死。
目的:应用CT灌注成像(CT perfusion imaging,CTPI)诊断超急性期脑梗塞,并对缺血半暗带组织灌注情况进行动态观察,了解急性期梗死灶周围是否仍然有缺血半暗带组织存在。
材料与方法:发病时间在6小时内临床怀疑脑梗塞的26例患者进行头颅CT平扫及CTPI检查,测量病变中心区、周围区及镜像侧脑血流量(CBF)、脑血容量(CBV)、平均通过时间(MTT)及各个参数图异常灌注区面积,并根据“同侧/对侧”的公式计算相对脑血流量(rCBF)、相对脑血容量(rCBV)、相对平均通过时间(rMTT)。第一次扫描24小时后复查CT平扫及CTPI,并与第一次扫描结果对比。
结果:第一次CT平扫示非责任的陈旧性脑梗塞6例,其余20例均未见异常。第一次CTPI示超急性期脑梗塞20例,其中16例存在缺血半暗带,4例无CBF/CBV不匹配区存在;其余6例诊断为TIA。复查CTPI示超急性期存在缺血半暗带的16例病例于急性期梗死区周围仍然存在低灌注区,与超急性期缺血半暗带rCBF、rCBV及rMTT比较无明显差异(t分别为2.05,1.515,0.081,P>0.05)。超急性期缺血半暗带区rCBF、rMTT与TIA低灌注区比较有明显差异(t分别为2.868,3.717,P<0.05),而rCBV比较无明显差异(t=1.748,P>0.05)。急性期梗死区平均面积(1470.75±54mm2)较超急性期(1387±43 mm2)增加(t=3.72,P<0.05),梗死区面积增加与缺血半暗带所占比例有线性相关关系(spearman相关系数1.00,P<0.05)。
结论:缺血半暗带不仅仅存在于脑梗塞超急性期,在急性期亦有缺血半暗带的存在;CTPI不但能够诊断超急性期缺血性脑卒中,而且对不同发病时间脑梗塞病例是否存在缺血半暗带做出判断。
Purpose: To observe perfusion state of perihematomal areas in acute and subacute intracerebral hemorrhage(ICH) in hypertension patients with dynamic CT perfusion imaging, and ananyze whether or not there is ischemic penumbra ,and predict prognoses of perihematomal tissue.
Materials and Methods: Prospectively study was performed in 27 patients of acute ICH in acute and subacute phase with conventional plain CT and dynamic CT perfusion imaging. Cerebral blood flow(CBF)、cerebral blood volume(CBV) and mean transit time(MTT) of ipsilateral perihematoma and contralateral mirroring areas were calculated in acute and subacute hemorrhage,and rCBF(relative CBF)、rCBV(relative CBV)were obtained with equation: ipsilateral/ contralateral. Area of hypoperfusion in hematoma and perihematoma zone in the central section of hematoma were measued in acute phase, and so did that area surrounded by perihematomal enhancement rim in identical section with acute hematoma in subacute hematoma.
Results: There were significantly decreased CBF and CBV and prolonged MTT in the acute perihematomal zone against contralateral hemisphere(Z=4.213, 4.265,2.631,respectively,P<0.05).Decreased CBF (compared with contralateral areas,Z=4.600,P<0.05)in subacute perihematomal areas represented no significant difference with that in acute phase(compared with contralateral areas,Z=0.024,P>0.05).Decreased CBV(compared with contralateral areas,Z=3.652,P<0.05) in subacute perihematomal areas increased significantly compared with CBV in acute perihematomal areas (Z = 2.21 , P < 0.05).Area of hypoperfusion in hematoma and perihematoma zone in the central axial section of hematoma showed no significant difference with area surrounded by perihematomal enhancement rim in identical section with acute hematoma measured in subacute hematoma(Z=1.590,P<0.05).
Conclusion: Dynamic CTPI can demonstrate perihematomal hypoperfusion in patients with acute ICH,there is probably not ischemic penumbra in perihematomal areas.However,this hypoperfusion condition couldn’t be relieved remarkably after conservatively treatment,and perihematomal tissue under hypoperfusion might have outcome of necrosis at last.
Purpose:To diagnose hyperacute infarct and study hemodynamics of ischemic penumbra in hyperacute and acute infarct with CT perfusion imaging(CTPI).
Materials and Methods: Prospectively study was performed in 26 patients with conventional plain CT and CTPI,who were admitted within 6 hours of symptom onset. Cerebral blood flow(CBF)、cerebral blood volume(CBV) and mean transit time(MTT) of ipsilateral lesions and contralateral mirroring areas and area of abnormal perfusion in functional maps were measured,and relative CBF(rCBF)、relative CBV(rCBV)、relative MTT(rMTT)were obtained with following equation: ipsilateral/ contralateral. The same protocol was performed 24 hours after the first time examination.
Results: Conventional plain CT demonstrated 6 cases with old irresponsible infarct lesions,the rest 20 cases no abnormalities in the first time examination. TIA was found in 6 cases,and hyperacute infarct in 20 cases with CTPI,in which there were 16 cases with ischemic penumbra,the rest 4 cases without mismatch of CBF/CBV. Hypoperfusion also was figured out in these 16 cases in areas around infarct in acute phase.No significant difference was found in rCBF、rCBV and rMTT in ischemic penumbra between hyperacute and acute infarct ( t=2.05,1.515,0.081, respectively,P>0.05).There was significant difference in rCBF、rMTT between ischemic penumbra of hyperacute infarct and hypoperfusion areas of TIA ( t=2.868,3.717,respectively,P < 0.05 ) ,however,no significant difference in rCBV(t=1.748,P>0.05).The average area of infarct in acute infarct was 1470.75±54mm2 that was larger than that(1387±43 mm2)in hyperacute infarct(t=3.72,P<0.05).The extent of infarct growth showed significantly correlation with initial proportions of ischemic penumbra to hypoperfusion(r=1.00,P<0.05).
Conclusion:Ischemic penumbra was found not only in hyperacute infarct,but also might be found in acute infarct.CTPI could demonstrate accurately hyperacute ischemic infarct,and analyze whether or not there is ischemic penumbra and observe its development in different phases of ischemic infarct.
引文
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