Clinical Application Value Of Susceptibility Weighted Imaging And Arterial Spin Labeling In Early Ischemic Cerebral Stroke

Objective: To investigate the clinical application value of3.0T Magneticsusceptibility-weighted imaging(SWI) and arterial spin labeling (ASL) in early cerebralischemic stroke.Methods:30patients in our hospital with cerebral infarction were performed withconventional MRI.Among the patients,24males,6females, age31-85years(average63.4years).MRI scanning was performed on GE Signa HDx3.0T superconducting scannerand8-channel head phased array coil were used.The conventional sequence: T1WI, T2WI,DWI, MRA and SWI ASL. The raw data of SWI and ASL were post—processed inGEADW4.4and were used to generate the corrected phase image SWI minp images andthe pseudo color map.1、 Observing the SWI manifestations of all cases of cerebral infarctionand andslected the same size ROI in the phase diagram (40mm2), maximum cross section ofregion of interest and contralateral mirror area were measured and we took the averagephase values measured three times in adjacent levels. Then we went paired t test.Meanwhile presence of hemorrhage within the infarction and microvascular change aroundthe ischemia area were observed in the SWI minp images． Statistics P <0.05wasconsidered statistically significant.2、The largest cross-sectional area of high signal on DWI is measured as infarct size.On the scanned image of acceptable quality, We took the measurement of the cerebralblood flow both lesions and contralateral mirror area, selected ROI=40mm. Multiplemeasurements of the same lesion took the average, try to avoid the ventricular system,record the value and comparative analysis. To represent the Statistical values with mean±standard deviation (X±SD).The changes of cerebral blood flow in both cerebral lesions and contralateral mirror area were observed. While observing DWI, ASL, MRA variety oftechniques to display the signal characteristics of lesions, and the size and vascularrelationships. Statistics P <0.05was considered statistically significant.3、Depending on the relative cerebral blood flow (rCBF) values,the blood perfusionof the lesion side was divided into hypoperfusion, perfusion increased and perfusion nochange. rCBF=CBF lesion/CBF comparison. rCBF ratios of0.9to1.1was normalperfusion; rCBF ratio>1.1was high perfusion, rCBF ratios <0.9, low perfusion. Accordingto the small veins display in and around Ischemic lesions, cases will be divided into threetypes, namely, a normal vein, veins increased and venous reduce on the SWI. Mann-Whitney test was used for the results consistency in qualitative analysis between ASL andSWI.Results:1、In the group of30patients, the infarct size less than100mm2were12cases,8cases more than100mm2while the area range was50-2739mm2, multiple lesionsin8cases, single lesion in22cases, some single lesion involving multiple blood areas.2、Early corrective phase the mean cerebral lesion compared with the contralateralmirror area increased, with statistical significance(P<0．05)；30cases of acute cerebralinfarction patients, we found that SWI sequence compared with conventional MRI,can bemore sensitive to the discovery of hemorrhagic in infarction and old bleeding；In30casesof acute cerebral infarction we found two cases of thrombosis, performing the strip lowdensity along the blood vessels.3、In30cases of cerebral infarction, there were4cases that CBF values measured ofinfarct lesion higher than the CBF values of contralateral mirror area. The pseudo-colordisplay was significantly higher perfusion.3cases showed normal perfusion and23casesshowed low perfusion.The average of cerebral blood flow(rCBF)values0f the infarctionregions were lower than those of contralateml mirror regions(p<0.05)；One case in thisgroup MRA showed interrupt of one side of the middle cerebral artery，while multiplepatches high perfusion areas were showed in artery territory on ASL. Another one case ofmultiple ischemic stroking, that the main artery displayed stenosis, interrupted on MRAand Its low perfusion area was significantly larger than on DWI.4、25out of30patients of the two inspection results were consistent,22cases ofblood vessels to reduce on SWI while20cases represented on ASL as low perfusion, and8 cases showed no abnormal within vascular infarction while2cases showed perfusion nochange and3cases showed high perfusion on ASL. Qualitative analysis showed nostatistical difference between the two technologies (Z=0.296, P>0.05).Conclusion:1、Early corrective phase the mean cerebral lesion compared with thecontralateral mirror area increased, with statistical significance(P<0．05);Compared withconventional MRI and CT，SWI sequence can be more sensitive to display infarctionhemorrhage and old hemorrhage, playing a guiding role in use of thrombolytic therapy forclinical and strong anticoagulant drugs;Intravascular thrombosis can be observed onSWIminp images, provided a strong imaging basis for clinical thrombolytic therapy.2、Low perfusion detection of massive cerebral infarction was significantly betterthan low perfusion testing on a small area of cerebral infarction; Perfusion changes incerebral infarction using ASL-perfusion3.0T MR imaging can be basically and practicallyutilized for depicting cerebral blood flows; ASL combined with MRA improved specificityand sensitivity of examination。3、SWI can Indirectly demonstrate the hemodynamic states of ischemic tissue andprovide a new simple technique for evaluating brain perfusion status;SWI can clearlyshows the tiny veins around the lesion which indicate the formation of collateralcirculation around infarct, suggesting a positive clinical recovery.