| ?Background?With the rapid development of imaging technology,the imaging assessment in the ischemic stroke caused by intracranial vascular stenosis is widely used.It plays an important role in the differential diagnosis of diseases,the selection of treatment modalities,and the judgment of efficacy and risk assessment.It has become increasingly prominent that every innovation of imaging technology will inevitably lead to the change and development of the concept of clinical diagnosis and treatment.Traditional vascular imaging mainly refers to the technique of luminal imaging,including digital subtraction angiography(DSA),computed tomography angiography(CTA)and magnetic resonance angiography(MRA).DSA,as the most classic vascular imaging technology,can clearly show the degree of vascular stenosis and the status of collateral circulation,which is considered to be the "golden standard" for vascular stenosis evaluation.However,its clinical application has been limited due to its potential harmness caused by radiation and contrast agent,and the risk of vascular injury and infection.Compared with DSA,CTA has been widely used in vascular assessment of ischemic stroke because of its fast scanning,lower risk of complications and less image distortion.However,there is still the risk of radioactive damage and side effect of the contrast agent.Unlike the two imaging techniques mentioned above,MRA has the advantage of being less traumatic and without radiological damage,but has longer scan times,higher patient selectivity,and susceptibility to motion disturbance.In summary,all of these three imaging techniques provide good luminal imaging in spite of their respective strengths and weaknesses.Histological studies of diseased vessels have found that the same degree of stenosis may result from completely different causes or to varying degrees of wall lesion.Therefore,in addition to simply assess the extent of stenosis,the assessment of wall lesions is even more important.In recent years,vessel wall imaging using the "black blood" technique of high-resolution magnetic resonance imaging(HR-MRI)has become an important means for diagnosis and risk evaluation of ischemic stroke.The purpose of this study is to investigate some image features of intracranial vascular lesions on and clinical significance of these imaging features.Part ?: New Vessels Formation in Young Strokes with Isolated Steno-occlusive MCA ?Objective?New Vessels formation(NVF)along the steno-occlusive middle cerebral artery(MCA)is often observed in digital subtraction angiography(DSA)imaging.In the study,we aim to explore the clinical relevance of NVF in young stroke patients with isolated middle cerebral artery(MCA)stenosis.?Method?We retrospectively reviewed the digital subtraction angiography(DSA)images of 93 young ischemic stroke patients(age?45 years old)in our center from January 2006 to June 2016.All the patients were diagnosed with isolated steno-occlusive middle cerebral artery(MCA)disease.NVF was defined as new vessels formation along the stenotic MCA on anteroposterior DSA projection.The association between NVF and functional outcome were analyzed.?Results?The prevalence of NVF was 0 in moderate stenosis,15.8% in severe stenosis and 53.7% in MCA occlusions.The presence of NVF had a strong correlation with the severity of MCA stenosis(r=0.467,P <0.001).Compared to patients without NVF,patients with NVF were more likely to suffer an unfavorable functional outcome(6.2% vs.21.4%,p=0.061)at 3months.Univariate logistic regression showed that NVF was associated with unfavorable outcome [Odds Ratio(OR)= 4.159,95% confidence intervals(CI)=(1.072,16.137),P = 0.039].?Conclusions?This study demonstrated that NVF were associated with poor clinical outcome in young ischemic stroke patients whom were diagnosed with isolated steno-occlusive MCA.Part ?: Clinical Significance of Plaque Enhancement in Patients with Symptomatic Intracranial Atherosclerotic Stenosis: A High-Resolution Magnetic Resonance Imaging Study ?Objective?High-resolution magnetic renounce imaging(HRMRI)has been proved to be an ideal technique to observe and evaluate the characteristics of atherosclerotic plaques in intracranial arteries.This study aimed to investigate influencing factors and clinical significance of plaque enhancement in patients with symptomatic intracranial atherosclerosis.?Method?Between July 2016 and November 2017,a total of 73 symptomatic patients with intracranial artery stenosis confirmed by digital subtraction angiography(DSA)were prospectively recruited,and all patients underwent HRMRI examination.The protocol included DWI,3D time-of-flight MR angiography,pre and post-contrast 3D Cube T1 and cross-sectional T1 WI.Of the 73 patients,37 were identified as atherosclerosis.The patients were divided into 2 groups according to whether the plaque was enhanced or not.The demographic data,risk factors,laboratory tests and the imaging features of the plaques were analyzed to find out the influencing factors of plaque enhancement.Patients were divided into new ischemic stroke group and TIA group according to DWI results,and the relationship between plaque enhancement and infarction was analyzed.?Results?Compared to patients without plaque enhancement,patients with plaque enhancement had a higher level of leukocyte(7.50 ± 2.30 vs 5.80 ± 1.00,p = 0.018),a higher prevalence of severe vascular stenosis [mild cases(0),moderate cases(13%)and severe cases(86.4%)vs mild cases(23.1%),moderate cases(23.1%)and severe cases(53.8%),p=0.040] and a lower prevalence of smoking(13.6% vs 46.2%,p = 0.050].Plaque enhancement accounted for a higher proportion of patients with ischemic stroke(71.4% vs 50%,p = 0.288),but there was no significant difference between the patients diagnosed with ischemic stroke or TIA.?Conclusions?In patients with symptomatic intracranial atherosclerosis,the degree of vascular stenosis and the level of leukocytes in patients were related to plaque enhancement.In addition,plaque enhancement was not associated with infarctions in patients with symptomatic atherosclerosis. |
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