Objective To probe into the relation of cerebral perfusion pressure（CPP） and change of cisterna ambiens in CT images of patients suffering from acute craniocerebral injury with change of illness and outcome;to quantify indexes in preoperative evaluation

choose favorable opportunity for treatment

guide to choosing opportunity for clinical operation and drug use

and improve success rate in the treatment of patients with craniocerebral injury.Method Values of CPP

CT cisterna ambiens and glasgow coma and outcome scale（GCS） in 153 cases of patients with acute craniocerebral injury treated in our hospital from march 2011 to february 2012 were retrospectively analyzed.The patients were divided into three groups according to indexes in which the CPP was >70 mmHg

50～70 mmHg and <50 mmHg respectively with 51 cases in each group.The three groups were followed up for more than three months and curative effects were compared.Results In group A consisted of patients with CPP>70 mmHg

the surgery was performed when the value of CT cisterna ambiens was at 0.4 mm

and there were 28 cases（54.9%） whose outcomes were good;in group B consisted of patients with CPP 50～70 mmHg

the surgery was performed when the value of CT cisterna ambiens was at 0.7 mm

and there were 40 cases（78.4%） whose outcomes were good;in group C consisted of patients with CPP<50 mmHg

the surgery was performed when the value of CT cisterna ambiens was at 2.2 mm

and there were 45 cases（88.2%） whose outcomes were good.Occipitofrontal diameter of cisterna ambiens was positively correlated with GCS（r= 0.564

p<0.01）.Conclusion For cases with disturbance of consciousness becoming severe

the more significant the change of cisterna ambiens state was

the less GCS was.The change of two factors in patients with acute craniocerebral injury such as value of CPP and CT cisterna ambiens was evaluated to choose proper opportunity for operation and make rational treatment scheme.