Experimental study in the effect of various intracranial hypertension upon the cerebral blood flow by transcranial Doppler / 中华超声影像学杂志

Objective To investigate the changes of transcranial Doppler (TCD) patterns and parameters in various intracranial hypertension.Methods Sixty rabbits were randomized into 3 groups:control group,the group of mild-to-moderate intracranial hypertension,the group of serious intracranial hypertension.Acute intracranial hypertension was induced by inflating the balloon inserted into the epidural space.Blood flow velocity was measured with TCD and intracranial pressure (ICP) as well as cerebral perfusion pressure(CPP) was measured.Mannitol was injected to the animals of intracranial hypertension,blood flow velocity and ICP was measured.ResultsTwo characteristic flow patterns vere observed in the group of mild-to-moderate intracranial hypertension:high resistance pattern,systolic flow.At the last stage of extreme intracranial hypertension in the group of serious intracranial hypertension Doppler sonograms showed three characteristic flow patterns in the following sequence:retrograde diastolic flow,very small systolic flow and zero flow.Multiform retrograde diastolic flows were related to the phases of brain death.Very small systolic flow showed three shapes:systolic-spike,small systolic triangular and small double peak.AftermedicinaltreatmentICPdecreasedinthethegroupofmild-to-moderateintracranial hypertension,blood flow velocity also increased.After the same treatment IC,P and blood flow velocity did not change in the group of serious intracranial hypertension.ConclusionsAnalysing patterns and parameters of TCD may be helpful for evaluating ICP indirectly as well as clinical experience.

Experimental study in establishment of acute intracranial hypertension model and the effect of intracranial hypertension upon pattern of transcranial Doppler / 中华超声影像学杂志

Objective To establish the animal model of acute intracranial hypertension,investigate the changes of transeranial Doppler patterns in raised intraeranial pressure so that the necessary experimental evidence will be provided to clinical experience for monitoring intraeranial pressure (ICP) and cerebral perfusion pressure (CPP) using transeranial Doppler non-invasively. Methods Acute intraeranial hypertension was induced by inflating the balloon inserted into the epidural space. Blood flow velocity of basilar artery was measured with transcranial Doppler and intracranial pressure as well as cerebral perfusion pressure was measured. Results With progressive increase of intracranial pressure five characteristic flow patterns were observed, appearing in the following order: high resistance pattern, systolic flow, retrograde diastolic flow, very small systolic flow and zero flow. Conclusions Analysing patterns of TCD may be helpful for evaluating ICP and CPP qualitatively. The animal model is simple and strict so that it is worthy of being spreadcd.