The Imaging Of PWI, MRI And MRA Of Vertebro-basilar Insufficiency Perfusion

Background and Aim: The term of Vertibro-basilar insufficiency (VBI) is used inclinical after first named by neurologist on1960s. The aim of this study is attempt to clarify ifthere is ischemia in the post-circulation and discuss reason of VBI.Methods: We performed the MRI, MRA and PWI on23patients of VBI in ourhospital from January,2011to January,2012. The original imaging data is sent to SiemensLeonardo work station. And then four groups of parametric imaging are obtained, includingrelative cerebral blood flow (rCBF), relative cerebral blood volume (rCBV), relative meantransit time (rMTT), and time to peak (TTP). Color Doppler ultrasonic examination and CDFIare performed as routine examination in our hospital. The clinical feature and pathogeny areanalyzed.Results: The most common disease history is hypertension, heart disease, diabetes andhyperlipidemia. There are13cases (56.5%),6cases (26.1%),4cases (17.4%),4cases(17.4%), respectively. There are6cases (26.1%) have smoke history, which is as a risk factor.The most common symptom of VBI is vertigo (23cases,100%). All patients presentedwithout infarct of post-circulation by MRI. The patients were performed by MRA:13cases(56.5%) present cerebral vessel stenosis or occlusion.3cases (13.0%) have dysplasia.3cases(13%) have unnatural tortuosity of vessel.18cases (78.2%) present atherosclerotic plaque.23patients were performed PWI, MRI and MRA. There were19normal perfusion cases and4abnormal cases. Of the abnormal cases, there were only four case presented with anteriorcirculation abnormal (Fig.3.1). Two case was with TTP prolong along, two cases with TTPand rMTT prolong together. Two cases presented normal rCBF and rCBV;2cases presenteddepressed rCBF and rCBV. Other19cases were all normal in post-circulation.(Fig.3.2-3.5).Conclusion:1. The clinical presentation of VBI may be not consistent with the ischemic situation ofpost-circulation. The combination of PWI, MRI, MRA can provide more comprehensive evaluation.2. VBI with abnormal vessel may be in compensatory situation because of collateralcirculation. While the clinical feature begin to present, which indicates that there may besome focal lesion ischemia connected with the clinical feature. So these patients have to bepay close attention in case that they will develop to post-circulation infarction.3. Internal carotid artery stolen blood syndrome of anterior-circulation abnormal vesselalso can induce VBI, presented with clinical feature of post-circulation.