磁共振血管成像-弥散成像不匹配对预测急性缺血性脑卒中缺血半暗带的价值

目的研究急性缺血性脑卒中（AIS）超早期磁共振血管成像（MRA）一弥散成像（DWI）不匹配对预测缺血半暗带的价值。方法选择在发病6h内完成MRA、DWI及灌注成像（PWI）检查的大脑中动脉供血区脑梗死患者，MRA—DWI桓Ⅱ体女不匹配定义为MRA示大脑中动脉M1段闭塞，DWI的梗死体积〈25ml；MRA—DWI梗Ⅱ部＆不匹配定义为M1段闭塞，DWI的梗死部位评分（以Alberta梗死早期CT评分评价）≥7。结果共入选78例患者，MRA—DWI梗死体积不匹配预测：PWI—DWI不匹配的特异度为100％，灵敏度仅为46％。MRA—DWI梗Ⅱ部＆不匹配预测：PWI—DWI不匹配的特异度为100％，灵敏度为42．9％。结论AIS超早期MRA．DWI不匹配预测缺血半暗带有很高的特异度，可作为筛选进行溶栓治疗患者的手段。     

Proton magnetic resonance spectroscopy in patients with ischemic stroke

Proton magnetic resonance spectroscopy (¹H-MRS) is a non-invasive technique which has proved to be useful for monitoring various brain metabolites (N-acetyl-aspartate, choline, creatine-phosphocreatine, lactate). A total of 18 patients underwent a combined magnetic resonance imaging (MRI)/¹H-MRS protocol in order to evaluate the distribution of the metabolites in the various stages of cerebral ischemia. Our results show a marked decrease of N-acetyl-aspartate and a large content of Lactate during the early phases, and a decrease in N-acetylaspartate, choline and creatine-phosphocreatine (Cr-PCr) during the chronic phase.

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Sommario La risonanza magnetica protonica spettroscopica (¹H-RMS) è una tecnica non invasiva che si è dimostrata essere utile per il monitoraggio di alcuni metaboliti (N-Acetil-aspartato, Colina, Creatina-Fosfocreatina, Lattato) del tessuto cerebrale. Un totale di 18 pazienti è stato sottoposto ad un protocollo combinato di risonanza magnetica imaging e¹H-RMS per valutare la distribuzione dei metaboliti in differenti stati dell'ischemia cerebrale. I nostri risultati nelle fasi precoci mostrano un marcato decremento dell'N-Acetil-aspartato ed un notevole contenuto di lattato, mentre nella fase cronica un decremento dell'N-Acetil-aspartato, della Colina e Creatina-Fosfocreatina.

     

急性缺血性脑卒中伴发抑郁障碍的静息态脑功能磁共振成像研究

目的利用静息态脑功能磁共振成像(rsfMRI)技术探讨急性缺血性脑卒中伴发抑郁障碍患者的脑功能情况。方法对13例急性缺血性脑卒中伴发抑郁障碍患者(病例组)及13名性别、年龄、优势手与之相匹配的健康对照(对照组),进行常规MRI、rsfMRI扫描并采集图像,包括矢状位T1WI和轴位T1WI、T2WI、FLAIR、DWI像,以及rsfMRI图像,分析比较两组的局部一致性(regional homogeneity,ReHo)。结果病例组与对照组相比,双额上回内侧、左颞下回、左顶下小叶、右角回、右扣带回中部及右小脑的ReHo降低(P<0.01);右枕叶中部、双楔叶及距状沟的ReHo增高(P<0.01)。结论急性缺血性脑卒中伴发抑郁障碍患者在静息状态下存在多个脑区功能异常。     

磁共振成像液体衰减反转恢复高信号血管征对大脑中动脉急性脑梗死静脉溶栓治疗预后的影响

目的 探讨磁共振成像（MRI）液体衰减反转恢复（FLAIR）高信号血管征（HVS）对大脑中动脉（MCA）急性脑梗死患者静脉溶栓治疗的预后评估。 方法 选取60例静脉溶栓前进行了多模态MRI检查的急性脑梗死患者,回顾性分析其临床和影像学资料。将患者分为A组（HVS阳性,25例）和B组（HVS阴性,35例）。比较两组间临床和影像学特征及其预后情况。 结果 两组间发病至MRI检查时间、MRI检查至静脉溶栓时间及出血转化率的比较差异均无统计学意义（P>0.05）。入院时A组美国国立卫生研究院卒中量表（NIHSS）评分高于B组[（14.14±3.57） 分 vs （10.00±3.43） 分,P<0.001]。A组较B组近端大血管闭塞更多见（84.0% vs 14.3%,P<0.001）。A组溶栓治疗后3个月随访的改良Rankin评分高于B组[（2.80±0.87） 分vs （1.94±0.97） 分,P=0.001]。 结论 HVS阳性的急性脑梗死患者静脉溶栓后3个月预后不佳,近端大血管闭塞与HVS的出现有密切相关性,HSV阳性提示静脉溶栓预后较差。     

Latent cerebral artery stenoses on magnetic resonance angiography in a patient diagnosed as probable Alzheimer disease

Abstract A 65-year-old woman with hypertension developed slowly progressive memory disturbance and disorientation. She was diagnosed as having Alzheimer-type dementia according to clinical criteria. Later her cognitive deterioration was noted to fluctuate in parallel to her blood pressure. Magnetic resonance angiography and single photon emission computed tomography showed bilateral middle cerebral artery stenoses and middle cerebral artery watershed dominant hypoperfusion. It is postulated that the patient's cognitive disturbance may have originated from vascular lesions.     

Diffusion-weighted magnetic resonance imaging in two patients with polycythemia rubra vera and early ischemic stroke

Polycythemia rubra vera (PRV) is a rare myeloproliferative disorder with a high risk of ischemic stroke. Although thrombosis of large cerebral arteries is the most frequently presumed pathomechanism, various infarct patterns have been described in patients with PRV and ischemic stroke. We report two patients with mild acute ischemic strokes and known PRV, in whom a scattered lesion pattern was detected by diffusion-weighted magnetic resonance imaging (DWI), but was not visible on computed tomography (CT) and conventional magnetic resonance imaging (MRI). Further diagnostic work-up including extra- and transcranial Doppler sonography (ECD, TCD), transesophageal echocardiography (TEE), magnetic resonance angiography and Holter monitoring revealed no obvious sources of cerebral embolism in both cases. However, TEE in one patient demonstrated spontaneous echo contrast (SEC) in the left atrium. In both patients the symptomatology resolved completely. The detection of a scattered infarct pattern by DWI in patients with PRV and acute ischemic stroke has not been reported previously. DWI findings together with the SEC in one patient emphasize the assumption that a prothrombotic state with subsequent arterial embolism rather than local arterial thrombosis may be the underlying pathomechanism of stroke in some patients with PRV. Adding DWI to the diagnostic work-up may help to clarify etiology in patients with PRV and acute ischemic stroke.     

Posterior cerebral artery dissection on a serial magnetic resonance angiography

Posterior cerebral artery (PCA) dissection in children seldom is reported in the literature. This is the second report of acute PCA dissection with infarct occurring in a young child. A serial magnetic resonance angiography demonstrated a delayed and transient narrowing of the arterial caliber, which was consistent with a focal PCA dissection with delayed vascular recanalization. PCA dissection should be included in the causes of infarct in children and a thorough and serial neurovascular imaging should be considered if no cause of stroke is found.     

Prognostic value of the dense middle cerebral artery sign in patients with acute ischemic stroke

The presence of a dense appearance of the horizontal part of the middle cerebral artery (the “dense middle cerebral artery sign”) was looked for on CT scans taken on admission in 90 consecutive patients with ischemic stroke in the carotid artery distribution. The outcome of the 14 patients with the sign was poorer than that of 76 patients without the sign (Odds ratio 4.3). We suggest that this sign could be a useful prognostic variable in the acute phase of an ischemic stroke.

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Sommario è state ricercata retrospettivamente la presenza della immagine iperdensa del tratto orizzontale della cerebrale media (“dense middle cerebral artery sign”) negli esami TAC eseguiti in 90 pazienti consecutivi con sintomatologia riferibile ad ischemia acuta nel territorio del circolo carotideo. L'evoluzione clinica dei 14 pazienti in cui il segno della cerebrale media iperdensa è stato rilevato è stata peggiore degli altri 76 (Odds ratio 4.3). Gli autori suggeriscono che il rilievo di questo segno può rappresentare una utile indicazione prognostica precoce nei casi di ischemia cerebrale acuta.

     

Dominant ipsilateral posterior cerebral artery on magnetic resonance angiography in acute ischemic stroke

BACKGROUND: In acute infarction involving the anterior circulation, the ipsilateral posterior cerebral artery (PCA) often appears to be longer than the contralateral PCA on magnetic resonance angiography. We described this finding as dominant ipsilateral PCA (DIPCA). We sought to find the frequency of DIPCA and its predictors. METHODS: We recruited 164 consecutive individuals with acute infarct involving the anterior circulation, and analyzed their radiological and clinical features. RESULTS: DIPCA was noted in 27 patients (16.5%). It was more frequent in patients with than in patients without steno-occlusive disease of the ipsilateral anterior circulation (30.5 vs. 2.4%, p < 0.001). Multivariate analysis revealed a significant relationship between the severity of arterial lesions in the ipsilateral anterior circulation and DIPCA (p = 0.039). CONCLUSIONS: DIPCA may reflect increased leptomeningeal collateral flow via the ipsilateral PCA, and its development may be dependent on the stenotic anterior circulation.     

Multimodal biological brain age prediction using magnetic resonance imaging and angiography with the identification of predictive regions

Biological brain age predicted using machine learning models based on high‐resolution imaging data has been suggested as a potential biomarker for neurological and cerebrovascular diseases. In this work, we aimed to develop deep learning models to predict the biological brain age using structural magnetic resonance imaging and angiography datasets from a large database of 2074 adults (21–81 years). Since different imaging modalities can provide complementary information, combining them might allow to identify more complex aging patterns, with angiography data, for instance, showing vascular aging effects complementary to the atrophic brain tissue changes seen in T1‐weighted MRI sequences. We used saliency maps to investigate the contribution of cortical, subcortical, and arterial structures to the prediction. Our results show that combining T1‐weighted and angiography MR data led to a significantly improved brain age prediction accuracy, with a mean absolute error of 3.85 years comparing the predicted and chronological age. The most predictive brain regions included the lateral sulcus, the fourth ventricle, and the amygdala, while the brain arteries contributing the most to the prediction included the basilar artery, the middle cerebral artery M2 segments, and the left posterior cerebral artery. Our study proposes a framework for brain age prediction using multimodal imaging, which gives accurate predictions and allows identifying the most predictive regions for this task, which can serve as a surrogate for the brain regions that are most affected by aging.     

单侧大脑中动脉狭窄的脑磁共振灌注成像研究

目的探讨大脑中动脉(MCA)不同狭窄程度时的脑磁共振灌注加权成像(PWI)表现。方法对31例经DSA诊断为单侧MCA狭窄或闭塞患者行脑磁共振PWI检查,并对不同程度MCA狭窄状态下患侧和健侧大脑半球的脑灌注参数局部脑血流量(rCBF)、局部脑血容量(rCBV)、局部平均通过时间(rMTT)、局部达峰时间(rTTP)进行定量分析。结果31例患者中,DSA诊断单侧MCA轻中度狭窄14例,其中脑灌注异常11例;患侧大脑半球rTTP较健侧显著延长(P0.01)。MCA重度狭窄或闭塞17例,均出现异常灌注;患侧大脑半球rTTP较健侧显著延长(P0.01),而患侧rCBF较健侧明显减少(P0.05),患侧rMTT健侧亦显著延长(P0.05)。结论通过脑灌注成像参数综合分析,磁共振PWI能准确评估MCA狭窄程度和脑组织血供情况,可为脑缺血的临床诊断提供重要价值。     

缺血性脑卒中急性期CT灌注成像与临床的相关性

目的探讨CT灌注成像(CTP)对缺血性卒中急性期的诊断价值,并观察影像学检查与临床的相关性。方法31例急性半球梗死者在发病24h内行头颅CT和CTP检查,同时进行美国国立卫生院神经功能缺损评分(NIHSS),其中18例在发病后12～72h内行头颅MRI 弥散成像(DWI),25例于发病后14～80d复查CT,同时进行NIHSS评分。结果24h内CT和CTP诊断敏感度分别为25.8%和90.3%,6h内CTP诊断敏感度88.2%。DWI上高信号的范围与局部脑血容量(CBV)的缺损程度间有相关关系;最初NIHSS评分与灌注缺损面积及灌注缺损程度无相关关系,而最终NIHSS评分与DWI异常面积和梗死面积有相关关系。结论CTP对超早期半球缺血有诊断价值,能发现缺血半暗带,可成为急性半球缺血的常规检查。最终的神经功能缺损与DWI异常面积和最后梗死面积相关。     

Dynamics of regional distribution of ischemic lesions in middle cerebral artery trunk occlusion relates to collateral circulation

We describe the regional distribution of acute perfusion, diffusion, and final infarct lesions in middle cerebral artery (MCA) trunk occlusion. A total of 31 patients with acute ischemic stroke and MCA trunk occlusion were studied by multiparametric magnetic resonance imaging. Probabilistic maps of lesion distribution were generated. The probability of initial and final infarcts was highest in the central MCA region with decreasing probability toward the periphery where the probability of the tissue at risk of infarction to be saved was highest. The probability of brain regions being involved in acute diffusion lesions and evolving into or escaping from the final infarct relates to the anatomy of arterial blood supply.     

64层螺旋CT灌注成像和血管成像在急性缺血性脑卒中的应用

目的：探讨64层螺旋CT 灌注成像（CTP）、CT血管成像（CTA）在急性缺血性脑卒中的应用价值。方法对30例急性缺血性脑卒中患者,于发病12 h内行头CT平扫、CTP、CTA检查,分析平扫及灌注CT表现,计算灌注缺损区CBF、CBV、MTT各参数值,与对侧相应区灌注参数进行比较,重建颈段和脑内动脉CTA图像,并于发病2～7 d复查CT平扫。结果30例急性缺血性脑卒中患者,15例C T平扫未发现异常,14例可见腔隙梗死灶或软化灶,1例可见脑梗死早期低密度改变。10例C T P未见明显异常,20例C T P发现与临床症状相对应的大小不等的灌注减低区,18例可见不同范围缺血半暗带。CTA 显示12例未见明显异常,18例可见血管狭窄或闭塞。结论 CTP、CTA能够快速准确反映缺血部位及范围,显示缺血半暗带,判断闭塞血管,对早期诊断急性脑梗死和指导溶栓治疗具有重要价值。     

脑微出血与急性缺血性卒中的临床关系分析

目的探讨急性缺血性卒中(AIS)患者脑微出血(CMBs)的危险因素,并进一步探讨CMBs与脑卒中病灶面积和部位的相关性。方法收集2014-1-2015-12在作者医院神经内科住院的AIS患者226例,据是否存在CMBs分为CMBs组(111例)和无CMBs组(115例)。收集研究对象临床资料,采用头颅MRI对其CMBs、脑白质病变(WML)、陈旧腔隙性脑梗死(LI)、AIS病灶面积和部位进行评价,并采用Logistic回归、t检验、χ~2检验等分析影响AIS患者发生CMBs的危险因素。结果多因素Logistic回归分析显示年龄(OR=1.063,95%CI:1.025~1.104,P0.01)、高血压史(OR=3.488,95%CI:1.113~10.927,P0.05)、WML(OR=1.282,95%CI:1.155~1.423,P0.01)及陈旧LI(OR=5.815,95%CI:1.539~21.973,P0.01)是AIS合并CMBs的独立危险因素;CMBs分级与WML分级(r=0.354,P0.01)、陈旧LI分级(r=0.394,P0.01)均呈正相关;不同脑卒中病灶面积患者间CMBs检出率比较有统计学差异(χ~2=7.878,P0.05),其中新发LI患者更易检出CMBs(χ~2=6.084,P=0.0090.017),且CMBs越严重,这种差异越明显(z=-2.832,P=0.0050.017)。结论年龄、高血压史、WML及陈旧LI是AIS合并CMBs的独立危险因素,且CMBs严重程度随WML、陈旧LI的严重程度增加而增高。AIS患者CMBs检出率与梗死灶面积有关,在新发LI中更易被发现。     

Thigh muscle function in stroke patients revealed by velocity-encoded cine phase-contrast magnetic resonance imaging

Current methods of clinical assessment of muscle coordination and function after stroke do not provide information on deep muscles. The objective of this study was to examine how stroke affects both superficial and deep muscles' coordination and whether muscle function improves after rehabilitation. Muscle function, coordination, and activity of quadriceps femoris (QF) and hamstrings were evaluated in 10 stroke patients with mild hemiparesis and in 6 controls using velocity-encoded cine phase-contrast magnetic resonance imaging (VE-PC MRI), surface electromyography (sEMG), and maximal voluntary isometric contraction torque (MVC). At baseline, the peak muscle velocity of the rectus femoris (RF) and the ratio between the peak velocities of the RF and vasti were lower in the affected limb (AL) of stroke patients than in controls. Co-contraction of agonists and antagonists was higher in the AL than in controls. Muscle activity measured by sEMG showed similar behavior. After rehabilitation, the activity ratio of hamstrings and adductors to QF decreased slightly toward normal so there were no significant differences between the AL and controls. Impaired biarticular RF muscle function in stroke patients is the limiting factor during knee extension-flexion movements. After rehabilitation, improved functional performance was partly explained by the fact that the activities of the RF and vasti became more synchronized. VE-PC MRI can provide quantitative in vivo measurements of both superficial and deep muscles, and the information acquired after stroke can be utilized to render therapy more efficient and individually tailored.     

Transcranial doppler in acute ischemic stroke of the middle cerebral artery territories

We have investigated the reliability of transcranial doppler compared with cerebral angiography in acute ischemic stroke in the middle cerebral artery territories. We studied 48 patients, 28 men and 21 women, mean age 68.1 (range 54–75), observed within 5 h of the onset of ischemic stroke in the middle cerebral artery territory. Ultrasound evaluation (duplex scanner and transcranial doppler) and cerebral angiography were carried out in close sequence immediately after CT scan. CT was repeated by Day 7 to estimate the infarct size: 27/48 patients had intracranial arterial obstructions. An acoustic temporal "window" was not found in 6.25%. Transcranial doppler showed a sensitivity of 80.0% and a specificity of 90.0% compared with cerebral Angiography for patients with patent acoustic temporal "windows". Accuracy was 79.2%, when patients with no "windows" were included. With respect to intracranial internal carotid artery and middle cerebral artery mainstem, transcranial doppler showed a sensitivity of 95.0%, and a specificity of 92.0%. Including patients with no windows, accuracy was 87.5%. Conclusions: Our data suggest that Transcranial Doppler can be reliably used to demonstrate intracranial internal carotid artery or middle cerebral artery mainstem obstructions in the acute phase of a brain infarction.