The Study Of 3D T1-weighted Black Blood Sequence At 3.0 Tesla For The Diagnosis Of Cervical Artery Dissection

Background and objective: Cervical artery dissection(CAD)is a significant cause of ischemic stroke in young adults,with a prevalence of 8-25% of ischemic stroke in patients <45 years of age.Ischemic stroke is the most common complication,which often occurs in the first few days of CAD onset.As a result,the early and accurate diagnosis of CAD is helpful for appropriate treatment decision-making to prevent primary or recurrent stroke.Prior studies have found that as one of three-dimensional(3D)T1 black blood sequences,3D T1-weighted sequence of volumetric isotropic turbo spin echo acquisition(VISTA)at 1.5 Tesla was useful to diagnose CAD.In this study,we aimed to investigate the value of 3D T1 VISTA at 3.0 Tesla in the diagnosis of CAD,and discuss its limitations.Methods: We consecutively and prospectively included patients who were clinically suspected as having a CAD within 1 month of onset.All patients received 3D T1 VISTA examination at 3.0 Tesla and at least one examination of magnetic resonance angiography(MRA),computed tomography angiography(CTA)or digital subtraction angiography(DSA).The analysis of all imaging results was performed by two experienced neuroradiologists who were blinded to all of the patient information and the final diagnosis.For T1 VISTA,the diagnosis of CAD was based on the presence of intramural hematoma,intimal flap,double lumen and aneurysmal dilation.For MRA,CTA and DSA,the imaging signs for diagnosis of CAD including double lumen,intimal flap,pearl and string sign,string sign,and tapered occlusion.For cervical ultrasound,the diagnosis of CAD was based on the presence of double lumen,intimal flap,intramural hematoma,stenosis and/or occlusion of an arterial segment usually not affected by atherosclerosis(i.e.the distal part of the internal carotid artery 2.0 cm or more downstream of the carotid bifurcation,and the V2–V4 segment of the vertebral artery,respectively).The final diagnosis of dissection was based on the clinical history,physical examination,and all of the imaging tests.SPSS V.19.0(IBM,West Grove,Pennsylvania,USA)was used to perform the analysis.Since no gold standard for the diagnosis of CAD was available,the final diagnosis results were chosen to be the reference standard to calculate the sensitivity and specificity(including the corresponding 95% CI)for 3D T1 VISTA.Interobserver agreement for 3D T1 VISTA and the agreement between 3D T1 VISTA and DSA/cervical ultrasound for the diagnosis of CAD were examined by using the κ-coefficient of agreement.Fisher’s exact test was used for count data.The level of statistical significance was set at p<0.05.Results: A total of 46 patients were included in this study.All patients received 3D T1 VISTA at 3.0 Tesla and cervical ultrasound examinations,and 25 of them simutaneously received 3D T1 VISTA at 3.0 Tesla and DSA examinations.The final diagnosis of CAD was made for 21 patients.Diagnosis of dissection was made for 20 of the 21 patients after assessing T1 VISTA.The sensitivity and specificity for T1 VISTA were 95.2%(95% confidence interval,76.2% to 99.9%)and 100%(95% confidence interval,86.3% to 100%),respectively.The agreement between the two researchers for T1 VISTA for diagnosis of CAD was very good(κ=0.91).The agreement between 3D T1 VISTA and DSA for the diagnosis of CAD was very good(κ=0.92),and the agreement between 3D T1 VISTA and cervical ultrasound for the diagnosis of CAD was moderate(κ=0.56).For patients without acute artery occlusion,all of them had a definite conclusion with or without dissection by T1 VISTA(n=29).However,for 17 patients with acute artery occlusion,the possibility of dissection could not be excluded for 6 of them by T1 VISTA(p=0.001).Conclusions: 3D T1 VISTA at 3.0 Tesla was useful in the diagnosis of acute CAD.However,for some patients with total occlusion of the artery without typical imaging features of dissection,the unequivocal distinction between intramural haematoma and intraluminal thrombus may be not adequate by T1 VISTA alone.Future studies should investigate whether a follow-up scan,a contrast-enhanced imaging or an optimal VISTA technique could be helpful.