An Application Study Of Clinical Diagnosis With PCASL?3D-TOF-MRA And DSA In Patients With Ischemic Cerebrovascular Diseases

BackgroundCerebrovascular accident,also known as stroke,it is point to brain artery stenosis,occlusion,or rupture caused by various factors in patients with cerebrovascular diseases,and it causes acute cerebral blood circulation obstacle,clinically characterized by the signs and symptoms of brain dysfunction for once or permanently.The cerebrovascular accident is one of the common diseases endangering human health,with a high incidence,high mortality and high morbidity,etc.According to epidemiologic survey in China,with the incidence rate of stroke about 210 per 100,000;and the mortality rate is about 65 per 100,000;70%-80%of the survivors have different degree of disability and nearly half of the patients are lacking in self-care ability,and it will impose a heavy burden on families and society.Among them,the ischemic cerebrovascular disease accounts for about 70%,including the transient ischemic attack and cerebral infarction.Researching the reason,the brain vascular stenosis or occlusion,etc.lead to the brain perfusion regional blood de-compensation and central nervous system lesions.Thus,it is key to make early detection and clear vascular lesions to control the disease harmfulness,providing direction for early diagnosis of patients and timely treatment.Currently,the methods of using the DSA,CTA and MRA etc.are mainly adopted in the diagnosis.Digital Subtraction Angiography(DSA)applies a radiopaque contrast medium through the tube,and make continuous imaging the inspection area before the developer to reach the target blood vessels and the peak in target intravascular contrast medium concentration,and after the clearance of the developer;and make mask image without the developer in the continuous imaging,make subtraction angiography with image containing developer,and make subtraction angiography of the image in the digital image matrix by using computer,offset bone and soft tissue sections,and finally form the blood vessels images.At present,the digital subtraction angiography(DSA)is the gold standard for judgment of vascular abnormalities,but it's expensive,invasive,with defects such as radiation exposure,complexoperation and time consuming,thus not suitable for early sieve and census.The Computed Tomography angiography(CTA)applies the injection of iodine contrast agent quickly in peripheral vein,and collect data after the high speed multi-level continuous CT scans in target blood vessels by spiral CT.After the scans,make the image post-processing by volume rendering(VR)and curved planner reconstruction(CPR),rebuild and reconstruct the three-dimensional blood vessels image.CTA also need the contrast agent to make image,with the defects of radiation and iodine contrast agent allergy,and so on.By contrast,the MRI technology is more and more widely applied in vascular lesions diagnosisbecause the MRI features noninvasive,no contrast material,constant development of equipment and post-processing technology,etc.Magnetic reconance angiorgraphy,MRA displays the blood vessels of the patients according to the circulation of blood in using MRI such as phase shift and the enhanced effect of flow to make the stillness of the tissue around t as the reference object.3D-TOF-MRA is a MRA technology commonly used in clinic,with characteristics such as spatial resolution,accurate location,random orientation&random angle,wide scan,a variety of reset and more imaging sequence etc.It could completely display the part and scope of the mutations in blood vessels.3D-TOF-MRA has a good consistency with DSA in evaluation of degree of vascular stenosis.But 3D-TOF-MRA has its own defects,for example,it is usually sensitive for intracranial the aorta and its ?-? level branch of vascular lesions,and hemodynamic change of eddy current exaggerates the degree of vascular stenosis,etc.In 1992,Detre JA etc.has firstly proposed a MRI technology(ASL)-put the free diffused water proton of arterial blood as endogenous tracer agent to measure the cerebral perfusion.The technology gains the ROI image by using reverse pulse tag interest area(ROI)upstream of the arterial blood,and collecting images when the marked blood flow vessels into ROI,and making image subtraction angiography before and after the images marked;at the same time,gains the cerebral blood flow by using the spin exchange of the imaging layer of capillary zone and tissue water,which causes changes of the local tissue longitudinal relaxation time T1,and then make signal subtraction of the tissue T1 signal before and after ROI marked.In recent years,ASL technology has improved to pCASL.pCASL has a high quality of marking effectiveness,without administration of gadolinium(Gd)contrast agent;no additional hardware;mild magnetization transfer effect;little radio frequency energy deposition;high SNR,etc.Studies found that pCASL has a good consistency in cerebrovascular evalution with HR-MRI in judging the degree of intracranial vascular stenosis,and also point out that ASL has higher sensitivity and specificity than 3D-TOF-MRA,thus there was controversy in clinical choice.To investigate the value of ASL in ischemic cerebrovascular disease diagnosis,using DSA as a gold standard,to explore the sensitivity and specificity of pCASL and 3D-TOF-MRA,and to make comparison of the two methods with DSA,thus providing the basis for clinical application.ObjectiveTo study the value of pCASL,3D-TOF-MRA,and DSA in ischemic cerebrovascular disease diagnosis and make comparison.Methods(1)Source of caseSource comes from patients after diagnosis and treatment with ischemic cerebrovascular disease in our hospital neurosurgery from Jan.2016 to Jan.2017.(2)Inclusion criteria? Suddenly the following symptoms:the side(with or without associated facial)appeared physically unable or symptoms of numbness;on one side or facial numbness or unilateral convulsion involving mouth;a sudden negative words or language understanding unclear;eye gaze to one side;one or both eyes vision loss or fuzzy;dizzy vomiting;rare severe headaches and vomiting;disturbance of consciousness or serious twitching;? Patients in stable condition,cooperative patients;? Patients signed the informed consent(3)Exclusion criteria? Patients with atherosclerotic vascular diseases such as Moyamoya disease and vasculities;? Patients with intracerebral hemorrhage,intracranial tumor and craniocerebral trauma,etc.;? Patients without body metal(cardiac pacemaker or intracranial arteryclamps),and without claustrophobia;? Patients allergic to contrast agent;? Patients with severe heart,lung,liver,and kidney disease? Patients with low-quality image(4)Abort criteriaPatients with poor compliance,or serious adverse events,or other diseases that cannot accept the observation,abort.(5)Case detailsFinally 88 were included,with male 53 and female 35;average age is(67.82 ± 5.35);patients with a hypertension history were 67;patients with a history of diabetes were 13.(6)Inspection equipment and methodsAll included 88 patients are examined by pCASL,3D-TOF-MRA and DSA,examination time:pCASL and 3D-TOF-MRA within 24 hours after onset,DSA within 24 hours after MRI.? DSA examinationRequire all the patients fasting six hours before surgery.Use Digital subtracted angiography(Siemens,Germany)to make DSA detect:using Seldinger technology,via femoral artery puncture,selective intubation into the internal carotid artery and vertebral artery,injection of a moderate amount of nonionic media,in turn imaging,and get images.? 3D-TOF-MRA ? pCASL examinationAll MR scans used Philips Ingenia 3.0T magnetic resonance imaging system.T1W1 scanning parameters:TR(repetition time)2045 ms,TE(echo time)20 ms,FOV(Field of view)230 x 230 mm,Matrix 356 x 215,slice thickness 5.5 mm,intersection gap 1 mm,slices 21.T2W1 scanning parameters:TR 9000 ms,TE 120ms,FOV 230 x 230 mm,Matrix 328 x 201,slice thickness 5.5,intersection gap 1 mm,slices 21.3D-TOF-MRA scanning parameters:TR 23 ms,TE 3.5 ms,FA(flipangle)18 °,FOV 201 x 201 mm,matrix 404 x 256,slice thickness 0.8mm,intersection gap 0 mm,slices 160.pCASL scanning parameters:FFE technology,TR 4000 ms,TE 16 ms,FA 90 °,FOV 240 x 240 mm,matrix 88 x 88,slice thickness 6mm,intersection gap 1 mm,slices 16.(7)Vascular stenosis degree measurement and imaging analysisCorrect the ASL image in turn in MR post-processing workstation and obtain CBF image,ROI and measure CBF value.Compare with mirror side blood vessels,and judge whether the patients'lateral cerebral blood flow perfusion is abnormal.3D-TOF-MRA and DSA images are independently sketched for vascular stenosis rate measurement by two high qualification doctors on workstation,and analyzed by measurement criteria recommended by North American Symptomatic Carotid Stenosis Endarterectomy Collaborative Research Group,the conclusion is inconsistent,negotiated settlement,if not resolved,the third party ruling.Narrow rate(%)=(I-width on the most narrow site of artery/diameter on the far side of narrow lesions of the normal blood vessels)*100%.Narrow rate<50%,mild stenosis;50%-69%,moderate stenosis;70%-99%,severe stenosis;blood vessels occlusion or no enhancement,100%narrow orocclusion.If there are several narrow sites in one case,only choose the most serious to identify,and the parts in the evaluation in different methods should be the same.Set DSA as the reference standard,if DSA displays blood vascular stenosis,and pCASL displays the perfusion abnormalities of the same side of patients,or with no exception,the diagnosis is consistent,otherwise is inconsistent;MRA will be expected to show the same blood vascular stenosis,or with no exception,the two types of diagnosis are consistent,otherwise is inconsistent.Calculate 3D-TOF-MRA and pCASL to judge the sensitivity,specificity and accuracy of the intracranial vascular stenosis.(8)The occurrence of adverse events in the course of the trial(9)Statistical methodsAnalyze by SPSS20.0 for windows,p<0.05 shows statistically significant.Results(1)DSA checks out 79 cases of intracranial artery stenosis,9 other cerebrovascular diseases,and the incidence was 89.77%.pCASL checks out 74 cases of intracranial artery stenosis,14 other cerebrovascular diseases,and the incidence was 84.09%.3D-TOF-MRA checks out 73 cases of intracranial artery stenosis,5 other cerebrovascular diseases,and the incidence was 82.95%.(2)Set DSA as comparison,the sensitivity of intracranial artery stenosis of using pCASL is 91.14%,the specificity is 77.78%,the accuracy is 89.77%,with no statistical difference(P>0.05).Two methods of alignment is general(?= 0.553,P<0.05).(3)Set DSA as comparison,the sensitivity of intracranial artery stenosis of using 3D-TOF-MRA is 87.34%,the specificity is 55.56%,the accuracy is 84.09%,with no statistical difference(P>0.05).Two methods of alignment is weaker(? = 0.331,P<0.05)(4)No adverse events in the course of examination.Conclusions(1)Though both pCASL and 3D-TOF-MRA have the high consistency with DSA in judgment of intracranial artery stenosis of patients with ischemic cerebrovascular diseases,pCASL has higher alignment.Imaging need to be fast and efficient in evaluation of acute ischemic cerebrovascular diseases,pCASL could provide important hemodynamic information in short time,and in this study,it has outstanding advantages compared with 3D-TOF-MRA.(2)But pCASL cannot obtain artery imaging,thus,it is suggested to add pCASL to get more judgment based on 3D-TOF-MRA to improve the positive findings.