ASL For Unilateral Middle Cerebral Artery Stenosis Or Occlusion Of Brian Tissue Perfusion Imaging To Assess

Ischemic cerebrovascular disease is a common hazard to human health, and disability and death rates are very high, in which middle cerebral artery (middle cerebral artery, MCA) stenosis or occlusion is caused by ischemic cerebrovascular disease of the main reasons. Side of middle cerebral artery stenosis or occlusion occurred through Central willis and cerebral arteries before and after the traffic around or about to be compensatory blood flow can also be accepted by the cortical collateral circulation in arterial blood supply, so there is no brain tissue ischemia, hypoxia, clinical symptoms will not appear. However, some patients with good collateral circulation has not yet been established, resulting in vascular stenosis or occlusion of blood supply to areas of ischemic brain tissue, lack of oxygen change, which requires an effective method to assess cerebral artery stenosis or occlusion of blood vessels supplying the brain areas the existence of perfusion defects or low perfusion, for the selection of vascular stenting and thrombolytic therapy provide the basis of imaging. Arterial spin labeling (Artery spin labelling, ASL) is a non-invasive method of perfusion imaging. In recent years, a substantial amount of research has proven its objectivity, this article analyzed 36 cases of patients with conventional MRI, MRA, DWI, DSC and the changes in ASL, ASL to explore this new technology on the middle cerebral artery stenosis or occlusion and reperfusion of information diagnostic value, in order to provide a basis for guiding clinical treatment.Main Methods: This study collected a total of 36 cases of TIA patients and 5 healthy volunteers, all medical records are used Siemens Trio Tim 3.0 T superconductive magnetic resonance imaging systems. Line of conventional MRI axial T1WI, T2WI and fat pressurized water pressure as scanning. SE axial T1WI spin-echo sequence used, TR: 440ms, TE: 2.46ms, scan time: 1 minute and 20 seconds. The use of TSE axial T2WI FSE, TR: 5000ms, TE: 93ms, scan time: 1 minutes and 12 seconds. FOV of these sequences are 220mm×220mm. Axial fat pressurized water pressure as: TR: 8000ms, TE: 93ms, TI: 2371.5, sequence FOV is 199mm×220mm, the time is 2 minutes 26 seconds. DWI using EPI sequence, the proliferation of sensitive three gradient directions, b=0s/mm2 and b= 1000s/ mm2, TR: 3800ms, TE: 93ms. DSC scan parameters for the TR: 1400 ms, TE: 32ms, FOV was 23cm, matrix 128x128. ASL scan parameters: the specific parameters are as follows: TR3000ms, TE 11 ms, Inversion slab 100 mm, TI1 700 ms, TI1 stop1600 ms, TI2 1800 ms, FOV 220mm×220 mm, bandwidth2232 Hz / pixel, Matrix 64×64, floors 15, slice thickness 6 mm, interval 25%, measurements 101, scan time 5 minutes and 14 seconds. After the scan is complete the original image sent to the Siemens workstations, image processing, DWI scan the machine automatically after the completion of ADC maps, observation, analysis, comparison DWI and DSC, ASL situation shows that the size of lesions. PWI-DSC of the original image to the workstation using dedicated software for image post-processing, the MTT, TTP, CBV, CBF map, in the CBF maps from regions of interest (regions of interest, ROI) and the corresponding contralateral area. ASL image spread to workstations into a single image, the use of hand-painted with the ipsilateral side from the disease of interest (ROI).The results: DSC to check the degree of ipsilateral and contralateral perfusion change, DSC perfusion affected the degree of change in check, T = 2.91,αlevel at 0.05, P<0.01, there is statistical significance. ASL to check the degree of ipsilateral and contralateral changes in perfusion, T=2.37,αlevel at 0.05, P <0.05, with statistical significance. It just goes to show that ASL without contrast injection, the perfusion of small invasive method of examination and inspection for perfusion defects or obvious hypoperfusion. Comparative DSC and ASL perfusion method showed that the extent of the affected side, chi-square value of -0.984, P=0.325>0.05 for no significant difference. DSC, ASL perfusion images show the degree of comparison found: ASL and DSC image to match the nine cases, both the performance of perfusion delay; ASL> DSC12 cases, which showed five cases of ASL perfusion defects, DSC showed delayed perfusion. MRA showed the existence of middle cerebral artery stenosis or occlusion, and DWI, DSC and ASL images have no obvious abnormalities in 7 patients. ASL image display as DSC perfusion images show the extent of the ideal image ASL showed seven cases of delayed reperfusion display range wider than that of the DSC area. At the same time line DWI, PWI (DSC and ASL) 21 patients were observed images are found PWI> DWI, showed ischemic penumbra.Conclusion: 1,using ASL completely non-invasive method of measuring CBF data, the extent of quantitative perfusion analysis, and implementation of convenient, easy to operate, such perfusion imaging of ischemic cerebrovascular disease can be sure of the diagnosis.2,ASL combination with DWI, indicating ischemic penumbra for the clinical development of effective treatment programs provide help to improve the prognosis of patients with level.