Artificial intelligence software for assessing brain ischemic penumbra/core infarction on computed tomography perfusion:A real-world accuracy study

BACKGROUND With the increasingly extensive application of artificial intelligence(AI)in medical systems,the accuracy of AI in medical diagnosis in the real world deserves attention and objective evaluation.AIM To investigate the accuracy of AI diagnostic software(Shukun)in assessing ischemic penumbra/core infarction in acute ischemic stroke patients due to large vessel occlusion.METHODS From November 2021 to March 2022,consecutive acute stroke patients with large vessel occlusion who underwent mechanical thrombectomy(MT)post-Shukun AI penumbra assessment were included.Computed tomography angiography(CTA)and perfusion exams were analyzed by AI,reviewed by senior neurointerventional experts.In the case of divergences among the three experts,discussions were held to reach a final conclusion.When the results of AI were inconsistent with the neurointerventional experts’diagnosis,the diagnosis by AI was considered inaccurate.RESULTS A total of 22 patients were included in the study.The vascular recanalization rate was 90.9%,and 63.6%of patients had modified Rankin scale scores of 0-2 at the 3-month follow-up.The computed tomography(CT)perfusion diagnosis by Shukun(AI)was confirmed to be invalid in 3 patients(inaccuracy rate:13.6%).CONCLUSION AI(Shukun)has limits in assessing ischemic penumbra.Integrating clinical and imaging data(CT,CTA,and even magnetic resonance imaging)is crucial for MT decision-making.

Ischemic penumbra in retina endures： vascular neuropathology is reconciled

A physiological state of＂normoxia＂obtains when tissue oxygen tension（pO_2）is sufficient to drive mitochondrial respiration throughout a volume of cells.Between 30-40%of the available oxygen is normally extracted from hemoglobin as it passes through neural tissue.

Relationship between treatment types and blood–brain barrier disruption in patients with acute ischemic stroke:Two case reports

BACKGROUND Blood-brain barrier(BBB)disruption plays an important role in the development of neurological dysfunction in ischemic stroke.However,diagnostic modalities that can clearly diagnose the degree of BBB disruption in ischemic stroke are limited.Here,we describe two cases in which the usefulness of dynamic contrastenhanced magnetic resonance imaging(DCE-MRI)in detecting BBB disruption was evaluated after treatment of acute ischemic stroke using two different methods.CASE SUMMARY The two patients of similar age and relatively similar cerebral infarction locations were treated conservatively or with thrombectomy,although their sex was different.As a result of analysis by performing DCE-MRI,it was confirmed that BBB disruption was significantly less severe in the patient who underwent thrombectomy(P=3.3×10^(-7)),whereas the average Ktrans of the contralateral hemisphere in both patients was similar(2.4×10^(-5)min^(-1) and 2.0×10^(-5)min^(-1)).If reperfusion is achieved through thrombectomy,it may indicate that the penumbra can be saved and BBB recovery can be promoted.CONCLUSION Our cases suggest that BBB disruption could be important if BBB permeability is used to guide clinical treatment.

Asymmetrically hypointense veins on T2~*w imaging and susceptibility-weighted imaging in ischemic stroke

AIM:To review the literature on the assessment of venous vessels to estimate the penumbra on T2*w imaging and susceptibility-weighted imaging (SWI). METHODS:Literature that reported on the assessment of penumbra by T2*w imaging or SWI and used a validation method was included. PubMed and relevant stroke and magnetic resonance imaging (MRI) related conference abstracts were searched. Abstracts that had overlapping content with full text articles were excluded. The retrieved literature was scanned for further relevant references. Only clinical literature published in English was considered, patients with Moya-Moya syndrome were disregarded. Data is given as cumulative absolute and relative values, ranges are given where appropriate. RESULTS:Forty-three publications including 1145 patients could be identified. T2*w imaging was used in 16 publications (627 patients), SWI in 26 publications (453 patients). Only one publication used both (65 patients). The cumulative presence of hypointense vessel sign was 54% (range 32%-100%) for T2* (668 patients) and 81% (range 34%-100%) for SWI (334 patients). There was rare mentioning of interrater agreement (6 publications, 210 patients) and reliability (1 publication, 20 patients) but the numbers reported ranged from good to excellent. In most publications (n = 22) perfusion MRI was used as a validation method (617 patients). More patients were scanned in the subacute than in the acute phase (596 patients vs 320 patients). Clinical outcome was reported in 13 publications (521 patients) but was not consistent. CONCLUSION:The low presence of vessels signs on T2*w imaging makes SWI much more promising. More research is needed to obtain formal validation and quantification.

Magnetic resonance diffusion-perfusion mismatch in acute ischemic stroke:An update

The concept of magnetic resonance perfusion-diffusion mismatch(PDM) provides a practical and approximate measure of the tissue at risk and has been increasingly applied for the evaluation of hyperacute and acute stroke in animals and patients.Recent studies demonstrated that PDM does not optimally define the ischemic penumbra;because early abnormality on diffusion-weighted imaging overestimates the infarct core by including part of the penumbra,and the abnormality on perfusion weighted imaging overestimates the penumbra by including regions of benign oligemia.To overcome these limitations,many efforts have been made to optimize conventional PDM.Various alternatives beyond the PDM concept are under investigation in order to better define the penumbra.The PDM theory has been applied in ischemic stroke for at least three purposes:to be used as a practical selection tool for stroke treatment;to test the hypothesis that patients with PDM pattern will benefit from treatment,while those without mismatch pattern will not;to be a surrogate measure for stroke outcome.The main patterns of PDM and its relation with clinical outcomes were also briefly reviewed.The conclusion was that patients with PDM documented more reperfusion,reduced infarct growth and better clinical outcomes compared to patients without PDM,but it was not yet clear that thrombolytic therapy is beneficial when patients were selected on PDM.Studies based on a larger cohort are currently under investigation to further validate the PDM hypothesis.

Involvement of Apoptosis in 3-nitropropionic Acid-induced Ischemic Tolerance to Transient Focal Cerebral Ischemia in Rats

The involvement of apoptosis in mitochondrial toxin 3 nitropropionic acid (3 NPA) induced ischemic tolerance to transient focal cerebral ischemia in rats and the mechanism was investigated. 3 NPA at a dose of 20 mg/kg or vehicle control was intraperitoneally into the rats. Three days later, rats were exposed to 2 h of middle cerebral artery occlusion followed by 24 h of reperfusion. Infarct volumes were assessed by 2,3,5 triphenyltetrazolinm chloride (TTC) staining 24 h after reperfusion. Neural cell apoptosis in cerebral ischemic penumbra was detected by terminal deoxynucleotidyl transferase mediated dUTP biotin in situ nick end labeling (TUNEL) and flow cytometry methods (FCM). The results showed that as compared to the vehicle treated group, pretreatment with 3 NPA could reduce the infarct volume by 23.3 % and decrease the number of TUNEL positive neural cells and apoptotic percentage by 47 % ( P< 0.05) and 44.9 % ( P< 0 01), respectively. It was concluded that the development of 3 NPA induced ischemic tolerance in brain might be related to the decreases in neural cell apoptosis.

Computed tomography perfusion and computed tomography angiography for prediction of clinical outcomes in ischemic stroke patients after thrombolysis

Cerebral blood perfusion and cerebrovascular lesions are important factors that can affect the therapeutic efficacy of thrombolysis.At present,the majority of studies focus on assessing the accuracy of lesion location using imaging methods before treatment,with less attention to predictions of outcomes after thrombolysis.Thus,in the present study,we assessed the efficacy of combined computed tomography（CT） perfusion and CT angiography in predicting clinical outcomes after thrombolysis in ischemic stroke patients.The study included 52 patients who received both CT perfusion and CT angiography.Patients were grouped based on the following criteria to compare clinical outcomes：（1） thrombolytic and non-thrombolytic patients,（2） thrombolytic patients with CT angiography showing the presence or absence of a vascular stenosis,（3） thrombolytic patients with CT perfusion showing the presence or absence of hemodynamic mismatch,and（4） different CT angiography and CT perfusion results.Short-term outcome was assessed by the 24-hour National Institution of Health Stroke Scale score change.Long-term outcome was assessed by the 3-month modified Rankin Scale score.Of 52 ischemic stroke patients,29 were treated with thrombolysis and exhibited improved short-term outcomes compared with those without thrombolysis treatment（23 patients）.Patients with both vascular stenosis and blood flow mismatch（13 patients） exhibited the best short-term outcome,while there was no correlation of long-term outcome with CT angiography or CT perfusion findings.These data suggest that combined CT perfusion and CT angiography are useful for predicting short-term outcome,but not long-term outcome,after thrombolysis.

URB597 exerts neuroprotective effect against transient cerebral ischemic injury via restor⁃ing autophagy flux and inhibiting neuronal necroptosis in mice

OBJECTIVE URB597(KDS-4103)is a potent and selective inhibitor of the enzyme fatty acid amide hydrolase(FAAH)and can ele⁃vate the level of oleoylethanolamide(OEA),a naturally occurring endocannabinoid in the brain.However,the effect of URB597 on cerebral isch⁃emic injury in mice remains unclear.METHODS Focal cerebral ischemia was induced by middle cerebral artery occlusion for 30 min followed by reperfusion for 24 h in mice.To observe the dose-dependent effect,URB597(0.04-5.00 mg·kg-1,ip)was administered at the same time of reperfu⁃sion.To determine the time-dependent effect,URB597(1.00 mg·kg-1,ip)was administered as a single dose at 0,1,3 or 5 h after reperfusion.Twenty-four hours after brain ischemia,Beder⁃son scoring test and grip strength test were used to evaluate the neurological function;brain in⁃farct volume was assayed by 2,3,5-triphenyltetra⁃zolium chloride(TTC)staining or diffusion-weighted magnetic resonance imaging(MRI).Laser speckle imaging(LSI)technique was used to assay the regional cerebral blood flow(rCBF);NeuN immunofluorescence staining was used to observe the neuron survival in the penumbra.To further investigate the underlying mechanism,au⁃tophagy flux related proteins(LC3-Ⅱ,P62 and LAMP2)and necroptosis related proteins(pRIPK3 and pMLKL)were detected by Western blotting and immunofluorescence staining.RESULTS Twenty-four hours after brain ischemia,URB597 dose-dependently improved neurological func⁃tion and reduced brain infarct volume.The most effective dose was 1.00 mg·kg-1;the therapeutic time window was within 1 h after ischemic stroke.The protective effect is further confirmed by the results that post-ischemic treatment with URB597(1.00 mg·kg-1)significantly increased neurons survival,promoted autophagy flux and reduced cell necroptosis in cortical penumbra after cerebral I/R.CONCLUSION URB597 dose-and time-dependently exerts a neuroprotective effect against acute cerebral I/R injury.This neu⁃roprotective effect of URB597 may be associated with its restoration of autophagy flux and inhibi⁃tion of neuronal necroptosis in the cortical penumbra.

By regulating IP3/PKC/TRPV4 pathway hyperoside induces endothelium-dependent vasodilatation in rat basilar artery following four vessel occlusion ischemia reperfusion

OBJECTIVE To investigate regulatory effects of hyperoside(Hyp)on IP3/PKC/TRPV4 pathway in rat cerebral basilar artery(CBA)subjected to global cerebral ischemia-reperfusion(I/R).METHODS The model of global cerebral I/R in rats was established by four-vessel occlusions methods.The treated rats were administrated with Hyp(50 mg·kg^-1)group,Hyp(50 mg·kg^-1)+HC-067047(10 mg·kg^-1),Hyp(50 mg·kg^-1)+2APB(2 mg·kg^-1),Hyp(50 mg·kg^-1)+BisI(2.5 mg·kg^-1),Hyp(50 mg·kg^-1)+2APB(2 mg·kg^-1)+BisI(2.5 mg·kg^-1).Hematoxylin-eosin(HE)and Nissl staining were performed and the contents of methane dicarboxylic aldehyde(MDA),neuron-specific enolase(NSE),S100β and the activity of lactic dehydrogenase(LDH)in serum were measured by enzyme-linked immunosorbnent assay(ELISA).The specific blocker N-nitro-L-arginine-methyl-ester(L-NAME)and indomethacin(Indo)were used to delete the prostacyclin(PGI2)and nitric oxide(NO)dependent relaxation.The protein expression level of TRPV4 was detected by Western blotting.Ca2+intensity in vascular smooth muscle cells was measured by confocal laser scanning microscope and flow cytometry was performed to observe the apoptosis of CBA endothelial cells after in vivo administration.RESULTS Hyp induced a dose-dependent relaxation of CBA in IR rats via a PGI2 and NO independent manner,as evidenced by alleviated patho⁃logical changes and up-regulated expression of TRPV4 protein in the endothelial cells from cerebral vessels.Hyp signifi⁃cantly reduced the contents of MDA,NSE,S100βand the activity of LDH in serum and decreased the fluorescence intensity of Ca2+in cerebral vascular smooth muscle cells by in vivo administration.The apoptotic rate of endothelial cells in Hyp treated group was significantly less than that in IR group.CONCLUSION Hyp does in fact ameliorate I/R injury by regulatingIP3/PKC/TRPV4 pathway.

Clinical characteristics and treatment strategies of acute ischemic stroke with internal carotid artery occlusion: a case report

Acute ischemic stroke has the characteristics of high disability,lethality and recurrence rate,which seriously threatens the health of middle-aged and elderly people.This article describes the acute ischemic stroke with internal carotid artery occlusion as the main clinical feature and discusses its treatment strategy.Treatment remedies:clinical diagnosis was carried out based on the present medical history,physical examination and craniocerebral CT(computed tomography).Neurological function was improved by intravenous thrombolysis,cerebrovascular angiography was used to clarify cerebrovascular occlusion,cerebral blood supply was identified by CT perfusion,and neurological function recovery was followed up.After intravenous thrombolysis,the patient’s consciousness turned clear and the right limb muscle strength recovery was not obvious,but the patient did not receive bridging therapy.Cerebral angiography showed about 90%stenosis at the beginning of the left internal carotid artery,and the blood flow terminated at the C7 segment.Cerebral CT perfusion imaging showed decreased perfusion in the left cerebral hemisphere,but the patient did not receive carotid endarterectomy and vascular bypass treatment.Post treatment evaluating:follow-up showed that NIHSS(National Institute of Health stroke scale)score was significantly decreased and limb function was significantly restored.Conclusion:early intravenous thrombolytic therapy can help reduce the area of ischemic penumbra and improve long-term prognosis.Severe vascular stenosis can stimulate vascular compensation,significantly reduce the range of ischemia when thrombus occurs,and effectively reduce the disability rate without bridging therapy.Whether vascular stenosis and occlusion are treated by vascular bypass,etc.,individualized plans should be made according to vascular compensation.

Cerebroprotection with recombinant neuroglobin plasmid in a rat model of focal cerebral ischemia

BACKGROUND： Adenovirus has been used to develop neuroglobin （Ngb） vectors. Although transfection efficiency is high, induced gene mutation, cytotoxicity, inflammation, and low exogenous gene content have limited its application. OBJECTIVE： To observe the effects of recombinant Ngb plasmid in a rat model of focal cerebral ischemia. DESIGN, TIME AND SETTING： Genetically engineered, randomized, controlled, animal experiment was performed at the Laboratory of Chongqing Medical University from May 2006 and January 2007. MATERIALS： 2, 3, 5-triphenyltetrazolium chloride was purchased from Shanghai Sangon Biological Engineering Technology and Services. Rabbit anti-rat Bcl-2 polyclonal antibody, rabbit anti-rat β-actin monoclonal antibody, and FITC-labeled goat anti-rabbit IgG were purchased from Sigma, USA. TUNEL apoptosis kit was purchased from Roche, Germany. METHODS： A total of 54 male, adult, Wistar rats were randomly assigned to 3 groups （n=18）： normal saline, plasmid control, and recombinant Ngb （pCDNA3.1 （＋）/Ngb）. Normal saline, plasmid pCDNA3.1 （＋）, and recombinant plasmid pCDNA3.1 （＋）/Ngb were separately injected into two sites in the rat cerebral cortex, and models of focal ischemia were established by occlusion of the right middle cerebral artery after 24 hours. MAIN OUTCOME MEASURES： Local ischemic damage was detected by 2, 3, 5- triphenyltetrazolium chloride staining, apoptosis in the penumbra was confirmed using the TUNEL method, and Bcl-2 protein expression in the penumbra was determined by indirect immunofluorescent staining and Western blot analysis. RESULTS： Compared with the normal saline and plasmid control groups, cerebral infarction size and the number of apoptotic cells in the pCDNA3.1 （＋）/Ngb group were significantly reduced （P 〈 0.01）. The percentage of Bcl-2-positive cells in the penumbra of the pCDNA3.1 （＋）/Ngb group was significantly increased （P 〈 0.01）. The relative expression level of Bcl-2 protein was increased by 40%-50%. CONCLUSION： Recombinant plasmid pCDNA3.1/Ngb provides neuroprotection by upregulating Bcl-2 expression and inhibiting cell apoptosis in the penumbra.

Rethinking the necessity of low glucose intervention for cerebral ischemia/reperfusion injury

Glucose is the essential and almost exclusive metabolic fuel for the brain.Ischemic stroke caused by a blockage in one or more cerebral arteries quickly leads to a lack of regional cerebral blood supply resulting in severe glucose deprivation with subsequent induction of cellular homeostasis disturbance and eventual neuronal death.To make up ischemiamediated adenosine 5′-triphosphate depletion,glucose in the ischemic penumbra area rapidly enters anaerobic metabolism to produce glycolytic adenosine 5′-triphosphate for cell survival.It appears that an increase in glucose in the ischemic brain would exert favorable effects.This notion is supported by in vitro studies,but generally denied by most in vivo studies.Clinical studies to manage increased blood glucose levels after stroke also failed to show any benefits or even brought out harmful effects while elevated admission blood glucose concentrations frequently correlated with poor outcomes.Surprisingly,strict glycaemic control in clinical practice also failed to yield any beneficial outcome.These controversial results from glucose management studies during the past three decades remain a challenging question of whether glucose intervention is needed for ischemic stroke care.This review provides a brief overview of the roles of cerebral glucose under normal and ischemic conditions and the results of managing glucose levels in non-diabetic patients.Moreover,the relationship between blood glucose and cerebral glucose during the ischemia/reperfusion processes and the potential benefits of low glucose supplements for non-diabetic patients are discussed.

Progesterone is neuroprotective by inhibiting cerebral edema after ischemia

Ischemic edema can alter the structure and permeability of the blood-brain barrier. Recent studies have reported that progesterone reduces cerebral edema after cerebral ischemia. However, the underlying mechanism of this effect has not yet been elucidated. In the present study, progesterone effectively reduced Evans blue extravasation in the ischemic penumbra, but not in the ischemic core, 48 hours after cerebral ischemia in rats. Progesterone also inhibited the down-regulation of gene and protein levels of occludin and zonula occludens-1 in the penumbra. These results indicate that progesterone may effectively inhibit the down-regulation of tight junctions, thereby maintaining the integrity of the blood-brain barrier and reducing cerebral edema.

多模式CT对急性前循环缺血性脑卒中患者缺血半暗带、梗死核心变化及预后的评估

目的 探讨多模式CT对急性前循环缺血性脑卒中患者缺血半暗带、梗死核心变化及预后的评估。方法 回顾性选取2021年1月至2023年6月来佛山市中医院诊治的疑似急性前循环缺血性脑卒中患者100例,治疗前后分别行多模式CT检查。分析头颅CT平扫(NCCT)、CT灌注成像(CTP)、CT血管成像(CTA)结果。比较急性前循环缺血性脑卒中患者缺血半暗带区、梗死核心区患侧与健侧的脑血容量(CBV)、脑血流量(CBF)、平均通过时间(MTT)、达峰时间(TTP)值;比较治疗前后急性前循环缺血性脑卒中患者缺血半暗带的灌注参数[相对脑血容量(rCBV)、相对脑血流量(rCBF)、相对平均通过时间(rMTT)和相对达峰时间(rTTP)];比较治疗前后急性前循环缺血性脑卒中患者梗死核心的灌注参数(rCBF、rCBV、rTTP、rMTT);分析脑组织异常灌注与血管狭窄的相关性。43例急性前循环缺血性脑卒中患者根据发病4.5~9.0 h内经溶栓治疗结果,比较预后良好(改良Rankin评分≤2分,n=28)与预后不良(改良Rankin评分>2分,n=15)缺血半暗带的rCBV、rCBF、rMTT、rTTP值。结果 100例疑似患者经NCCT检查发现,59例患者可见早期的低密度病灶,其余41例患者未见明显异常,NCCT阳性率为59.00%。CTP检查结果发现,100例患者中9例经过CTP检查灌注正常,其余91例患者脑灌注均有异常现象,与临床症状相符,CTP检查发现阳性率为91.00%。CTA检查结果发现,存在责任血管狭窄或闭塞者88例,无存在责任血管狭窄或闭塞者12例。多模式CT结果:急性前循环缺血性脑卒中缺血半暗带区健侧、患侧CBV比较,差异无统计学意义(P>0.05),患侧的CBF明显较健侧低,患侧的MTT、TTP明显较健侧高,差异均有统计学意义(P<0.05)。梗死核心区患侧的CBV、CBF明显较健侧低,MTT、TTP明显较健侧高,差异均有统计学意义(P<0.05)。与梗死核心区相比,缺血半暗带的rCBV、rCBF明显较高,rMTT、rTTP值明显较低,差异均有统计学意义(P<0.05)。治疗后,前缺血半暗带rCBV与治疗前比较,差异无统计学意义(P>0.05),rCBF较治疗前高,rMTT、rTTP较治疗前低,差异均有统计学意义(P<0.05)。血流灌注异常者中存在责任血管狭窄或闭塞发生率明显较血流灌注正常者高(95.6%vs.11.11%),差异有统计学意义(P<0.05)。发病4.5~9 h内经溶栓治疗患者43例,其中预后良好者28例,预后不良者15例。预后良好者前缺血半暗带rCBV与预后不良比较,差异无统计学意义(P>0.05),预后良好者rCBF较预后不良高,rMTT、rTTP较预后不良低,差异均有统计学意义(P<0.05)。结论 多模式CT可早期发现急性前循环缺血性脑卒中的缺血半暗带、梗死核心异常情况,可用于急性前循环缺血性脑卒中患者的预后判断。

多模式影像指导超时间窗急性大血管闭塞性脑卒中血管内再灌注治疗的应用研究

目的探讨超时间窗急性大血管闭塞所致的缺血性脑卒中患者经严格影像学评估后行急诊绿色通道血管内再灌注治疗的安全性和有效性。方法选取2021年1月至2022年12月在广东省中医院珠海医院救治的急性大血管狭窄或闭塞所致的缺血性脑卒中并经影像学评估存在缺血半暗带和侧支循环的36例患者作为研究对象,采用抽签法将36例患者分为观察组(19例)与对照组(17例)。观察组接受血管内有效再灌注治疗,对照组接受标准内科药物治疗。比较两组患者入院时、出院时、出院3个月的美国国立卫生研究院卒中量表(NIHSS)评分、改良Rankin量表(mRS)评分,比较两组患者出院3个月后良好临床结局,以及治疗30 d内脑卒中、症状性脑出血、死亡的发生率。结果观察组患者出院时、出院后3个月的NIHSS评分低于对照组,差异有统计学意义(P<0.05);观察组患者出院时、出院后3个月的NIHSS评分低于本组入院时的评分,差异有统计学意义(P<0.05)。观察组患者出院时、出院后3个月的mRS评分均低于对照组,差异有统计学意义(P<0.05);观察组患者出院时、出院后3个月的mRS评分均低于本组入院时,差异有统计学意义(P<0.05)。出院后3个月,观察组的良好临床结局率高于对照组,差异有统计学意义(P<0.05)。治疗30 d内,两组患者的脑卒中、症状性脑出血、死亡率比较,差异无统计学意义(P>0.05)。结论超时间窗急性大血管闭塞所致的缺血性脑卒中患者经严格影像学评估后急诊行血管内再灌注治疗可能是安全有效的。

DTI联合DWI对急性脑梗死早期缺血半暗带的定量评估价值

目的分析磁共振弥散张量成像(DTI)联合弥散加权成像(DWI)对急性脑梗死(ACI)早期缺血半暗带(IP)的定量评估价值。方法选取ACI患者80例,均行磁共振DTI和DWI检查,根据患者发病时间将其分为超急性期组(<6h,n=24)、急性期组(6~24h,n=26)和亚急性期组(24~72h,n=30),比较ACI患者梗死中心区、IP区、对侧镜像区的平均扩散系数(DCavg)、表观扩散系数(ADC)、异性指数(FA)值,并比较ACI患者不同发病时期IP区的rDCavg、rADC、rFA值。结果ACI患者不同区域DCavg、ADC、FA值比较:梗死中心区<IP区<对侧镜像区(P<0.05)。ACI患者不同发病时期IP区rDCavg、rADC、rFA值比较:超急性期组>急性期组>亚急性期组(P<0.05)。结论DTI联合DWI检查的相关定量参数对于ACI早期IP具有较高的评估价值,临床可借鉴应用。

磁共振3D-ASL灌注技术对急性缺血性脑卒中的筛查价值

目的本研究联合应用磁共振多模态成像技术,探讨3D-ASL灌注技术对急性缺血性脑卒中的筛查价值。方法前瞻性分析2019年10月至2022年11月由卒中通道于河南中医药大学第一附属医院磁共振科行头颅磁共振检查的55例单侧病变患者的影像资料,评估、测量DSC-PWI及3D-ASL两种成像方法,比较两者筛查急性缺血性脑卒中的一致性;比较3D-ASL脑血流值(CBF)的组间差异;计数血管高信号(FVH征)与动脉穿行伪影(ATA征)出现情况,总结两征象出现的规律。结果以DSC-PWI作为金标准,3D-ASL在评估AIS患者核心梗死区、血流灌注情况及缺血半暗带方面呈现出相当的诊断效能;3D-ASL测得的梗死核心区、IP区、健侧镜像区的CBF值三者之间具有显著统计学差异(P<0.05);患侧IP区脑组织FVH、ATA征象的出现呈较高一致性(=10.154,P>0.05)。结论3D-ASL技术可以对AIS患者进行精准的定性、定量影像评估,具有多重优势及较高的诊断价值,为临床诊疗提供了可靠的影像学依据。

磁敏感加权血管成像在急性缺血性脑卒中缺血半暗带评估中的应用

目的分析磁敏感加权血管成像(SWAN)在急性缺血性脑卒中缺血半暗带部位及范围评估中的临床应用价值。方法回顾性收集2019年1月至2022年12月在南京中医药大学连云港附属医院行磁共振检查急性期缺血性脑卒中患者25例,男15例,女10例,年龄(55.7±14.4)岁。均行弥散加权成像(DWI)、T2加权液体衰减反转恢复序列(T2 Flair)、SWAN及三维动脉自旋标记(3D ASL)序列检查,将DWI显示高信号区、表观弥散系数(ADC)显示低信号区判定为梗死核心区,分析SWAN序列提示突出血管征(PVS)阳性区域、3D ASL序列提示脑血流量(CBF)低灌注区域分别与梗死核心区间的不匹配范围差异,采用独立样本t检验。结果SWAN-DWI不匹配区的范围为(2289.42±721.47)mm^(2)、3D ASL-DWI不匹配区范围为(2331.59±730.71)mm^(2),两者差异无统计学意义(t=0.205,P=0.838)。结论利用磁共振SWAN序列提示的PVS可用于评估急性缺血性脑卒中缺血半暗带部位及范围,为临床治疗方案选择提供影像依据。

基于半暗带缺血区鉴别角度分析多模态MRI在不同时期脑梗死患者诊断中的价值

目的基于半暗带缺血区鉴别角度分析多模态MRI在不同时期脑梗死患者诊断中的应用价值。方法选取2021-05—2023-06在新疆医科大学第一附属医院接受检查的198例脑梗死疑似患者,根据发病时间分为A组(发病时间≤4.5 h)、B组(4.5 h<发病时间≤7 d)和C组(7 d<发病时间≤3个月),均接受常规MRI序列、扩散加权成像(DWI)、灌注加权成像(PWI)等多模态MRI技术和DSA检查,以DSA检查结果为金标准,比较常规MRI平扫、DWI和多模态MRI(常规MRI平扫+DWI+PWI)检查对3组脑梗死患者诊断的敏感度、特异度、准确率。制作3种检查方法诊断不同时期脑梗死患者的受试者工作特征(ROC)曲线,测算曲线下面积(AUC)。结果A组52例脑梗死疑似患者,确诊32例;B组103例脑梗死疑似患者,确诊67例;C组43例脑梗死疑似患者,确诊28例。在A组、B组、C组中,常规MRI平扫、DWI、多模态MRI 3种方法对脑梗死的诊断效能均有差异,以多模态MRI的灵敏度、特异度、准确率最高(P<0.05)。A组中常规MRI平扫、DWI、多模态MRI 3种方法诊断脑梗死的ROC曲线AUC值分别为0.6738、0.7642、0.8329,B组分别为0.6857、0.7714、0.8582,C组分别为0.6912、0.7806、0.8629,差异有统计学意义(P<0.05)。结论基于半暗带缺血区鉴别角度分析多模态MRI在不同时期脑梗死患者诊断中具有较高的临床应用价值,能够显著提高灵敏度、特异度、准确率及AUC值,值得推广应用。

3D pCASL不同标记后延迟时间评估急性缺血性脑卒中缺血半暗带体积时相对脑血流量阈值的选择

目的 探讨三维伪连续动脉自旋标记(3D pCASL)不同标记后延迟时间(PLD)评估急性缺血性脑卒中(AIS)缺血半暗带体积时相对脑血流量(rCBF)阈值的选择。方法 对42例AIS患者进行磁共振(MRI)常规序列成像、3D pCASL及动态磁敏感对比增强—磁共振灌注成像(DSC-PWI),将磁共振弥散成像、3D pCASL和DSC-PWI影像数据导入F-stroke软件自动分析,生成3D pCASL和DSC-PWI的缺血半暗带体积。以DSC-PWI的缺血半暗带体积作为参考标准,采用组内相关系数(ICC)分析PLD分别为1 525、2 525 ms时,rCBF<30%、<40%、<50%的缺血半暗带体积与DSC-PWI缺血半暗带体积的一致性;比较不同rCBF阈值的缺血半暗带体积与DSC-PWI的缺血半暗带体积的差异。结果 3D pCASL PLD为1 525 ms时,rCBF<40%、<50%的缺血半暗带体积与DSC-PWI的缺血半暗带体积具有一致性(ICC分别为0.595、0.791,P均<0.01);PLD为2 525 ms时,rCBF<50%的缺血半暗带体积与DSC-PWI的缺血半暗带体积具有一致性(ICC=0.577,P<0.01)。PLD为1 525 ms时,rCBF<40%的缺血半暗带体积与PLD=2 525 ms时rCBF<50%的缺血半暗带体积不存在显著差异(P>0.05)。结论 在3D pCASL中,1 525 ms和2 525 ms的PLD均可用于定量评估缺血半暗带,并且不同PLD时的rCBF阈值不同:短PLD(1 525 ms)应选择较高的rCBF阈值(<50%),而长PLD(2 525 ms)的rCBF阈值则要高于短PLD(1 525 ms)。