ASL In Different Delay Time Of Cerebral Blood Flow Perfusion In Patients With Cerebral Ischemia Research

Object:To evaluate patients whom cerebral ischemia and cerebral blood flowperfusion in different delay times with ASL technology in order to definite itsclinical value.Methords:Use GE750,3.0T, then examine24patients of cerebral ischemia withsignificant clinical symptoms, for each subject in T1WI, T2WI, FLAIR, MRA，DWI，DSCscans underwent ASL, use ASL technique obtained non-contrest anddelay2.5data, After the MR750workstation color image processing, TwoTerrier areas were measured latency in low perfusion patients, Select the objectsof interest region and then selected aLesion area regions of interest in ASL andDSC image, Corresponding contralateral normal area of each selected in a samearea, record their blood flow, on two parameters selected region of interest inthe same image size and location, Multiple measurements of blood flow in theselected region of interest then obtained the average value, then塔克the ratioof the two CBF,the most important avoid the ventricle, and Its location in thebrain gray matter as far as possible,then compared to the measurement results.Results:in24patients, the low perfusion area more than3cm in12cases,and9caseless than3cm2, THE show that the resule of the DWI,MRA and the DSC is thesame of the ASL image.The ASL image area results showed that the delay timeresulting non-contrest hypoperfusion smaller than the delay time obtaineddelay2.5hypoperfusion， Comparison of non-contrest and delay2.5ROIs by ASL perfusion images obtained CBF delay time，we can find that Theformer‘s CBF lower than the latterConclusions:If the same case to shorten the delay time, low perfusion area appears toexpand, Reduce cerebral blood flow, the phenomenon of amplificationperfusion degree hypoperfusion will be reduced，if you extend the delay timewill be relatively narrow zone of low perfusion, perfusion will reduce the degreeof relatively narrow. shorten the delay time made the results relatively sensitiveand can prompt early changes in cerebral ischemia of patients with lowperfusion. The different values obtained in different delay times, but in constantin the same low perfusion region, Therefore, the result of prolonged delayresulting can be more responsed hemodynamic in the brain abnormalities.TheASL techniques can be very good reactions in the brain tissue hypoperfusion,especially the study which United MRA and DWI sequences were showed thatASL technique can be better showed low perfusion, especially ischemicpenumbra detection,and has a good consistency with DSC technology, the delaytime of react perfusion’s scope and extent showed in ASL technology, Theresulting showed that the degree of ischemic brain tissue which marked in shorttime will be amplified, and The result is very sensitive to very early detection ofcerebral ischemia,that the more Delay time extended, the more accuratelyreflect cerebral hypoperfusion，two different methods can be used in clinicalsituations, as compared to the latter, the former is more suitable for the earlydiagnosis and screening.