Clinical Value Of Dynamic CT Perfusion Imaging In Stroke

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.