The Application Of Multimodal Image In Diagnosis Of Carotid Artery And Middle Cerebral Artery Lesions With Ischemic Stroke

PART ? The relationship between Quantitative Susceptibility Mapping and cerebral blood volume in patients with unilateral carotid artery and middle cerebral artery stenosisObjectiveTo study the relationship between Quantitative Susceptibility Mapping(QSM)and pathologic cerebral blood volume(CBV)in patients with unilateral carotid artery and middle cerebral artery stenosis.Materials and methodsTotally,26 patients with unilateral carotid artery and middle cerebral artery stenosis were retrospectively analyzed.Scanning was performed on the 3.0 T Siemens Magnetom Prisma scanner.MR images of all patients were acquired,including QSM,relative CBV and High resolution magnetic resonance imaging of carotid and cerebral arteries.By selecting a subcortical region of interest of the affected and contralateral brain tissue followed by Pearson test,the correlation between ?QSM and ?CBV was evaluated.ResultsA total of 14 patients with unilateral carotid artery stenosis and 14 patients with unilateral middle cerebral artery stenosis were involved.2 patients had both unilateral carotid artery and middle cerebral artery stenosis.We found a strong positive correlation with ?QSM and ?CBV(r=0.756,P<0.01).ConclusionQSM holds the potential for assessment of pathological cerebral blood volume in patients with unilateral carotid artery and middle cerebral artery stenosis non-invasively.PART ? Evaluating cervical artery dissections in young adults-A Comparison Study between High-Resolution MRI and CT AngiographyObjectiveTo compare the diagnostic values between high-resolution magnetic resonance(HR-MRI)and computed tomographic angiography(CTA)in young adults with ischemic stroke due to cervical artery dissections.Materials and methodsTotally 42 symptomatic patients were recruited in this study.Among them,38 patients underwent CTA,HR-MRI and Digital Subtraction Angiography(DSA),while the remaining 4 patients with vertebral artery dissections were diagnosed by follow-up.CTA and HR-MRI images were separately and blindly analyzed by two radiologists.The sensitivity,specificity,positive and negative predictive value of HR-MRI and CTA were calculated.The receiver operating characteristic(ROC)curves and AUC of each imaging modality were generated.ResultsA total of 20 carotid artery dissections,12 vertebral artery dissections and 10 non-dissected cervical arteries were involved.The inter-observer concordance of HR-MRI and CTA was moderate(?=0.806 vs.0.776).The sensitivity and specificity of HR-MRI and CTA on detecting the dissections were 87.5%vs.62.5%,and 90.0%vs.80.0%,respectively.Area under the ROC curve of HR-MRI(0.94[95%CI,0.86-0.97])was greater than that of CTA(0.87[95%CI,0.71-1.0]).ConclusionCompared to CTA,HR-MRI is more sensitive and specific for the diagnosis of cervical artery dissections in high-risk symptomatic patients.This study supports the value of HR-MRI to non-invasively diagnose cervical artery dissections of young adults.