磁共振弥散加权成像鉴别诊断脑脓肿与脑肿瘤坏死的临床研究

目的探讨磁共振弥散加权像(DWI)及表观弥散系数值(ADC)对脑脓肿与坏死囊变脑转移瘤诊断和鉴别的意义。方法选取2011-01—2015-01于我院进行脑脓肿、脑肿瘤坏死治疗的患者为研究对象,其中脑脓肿10例,脑肿瘤坏死12例,均进行常规磁共振检查及弥散加权检查。应用1.5T磁共振机SE-EPI序列,取b=1 000s/mm2,b=0s/mm2在脑脓肿脑炎期、包膜期及吸收期进行弥散信号测量,获得DWI图像,同时测量表观弥散系数值,并与坏死囊变脑转移瘤比较。结果常规MRI诊断敏感性、特异性分别为75%、70%,DWI诊断敏感性、特异性则分别为92%、90%;10例脑脓肿9例磁共振弥散加权图像表现为高信号,表观弥散系数值为0.335±0.098,12例脑肿瘤中11例坏死囊变部分磁共振弥散加权图像表现为低信号,表观弥散系数值2.481±0.391。结论在鉴别脑脓肿和坏死、囊变脑肿瘤方面磁共振弥散加权成像诊断的敏感性和特异性均明显高于常规MR诊断,帮助提高诊断的正确性。     

磁共振弥散加权成像对超急性期脑梗死的诊断价值

目的 研究磁共振弥散加权成像(DWI)在超急性期脑梗死诊断中的价值.方法 对51例脑梗死患者超急性期头颅核磁共振常规T1WI、T2WI序列与DWI序列的扫描结果进行比较.结果 51例脑梗死患者在临床症状出现后6h内,6例在T2WI序列上有长T2改变,48例DWI序列显示高信号,2者的阳性率有显著性差异(X2=18.01,P<0.01).结论 DWI对超急性期脑梗死的诊断准确、可靠,具有良好的临床应用价值.     

磁共振弥散加权成像对反复发作性脑梗死的诊断价值

目的 评价磁共振弥散加权成像在反复发作性脑梗死诊断中的应用价值.方法 对97例临床反复发作性脑梗死的患者进行头颅CT及MRI中的T1WI、T2WI、DWI、FLAIRWI的检查后,在DWI异常信号发生的部位与临床表现进行对比.结果 97例MRI检查中,在DWI上均有高信号和低信号,6例超急性期脑梗死在DWI上显示高信号,而T2WI及FLAIRWI未能显示,脑梗死急性期DWI均表现为高信号,亚急性期多数表现为高信号或略高信号,在DWI上出现高信号或略高信号的部位与临床表现相符的有77例.结论 DWI序列在临床诊断脑梗死中起着重要作用,在早期急性脑梗死显示能力优于常规序列,它能区分新旧梗死,有助于责任病灶的检出.对临床治疗有十分重要意义.但须结合常规序列及临床病史进行综合分析判断才能作出正确的诊断.     

磁共振DWI对脑脓肿与坏死囊变性胶质瘤的鉴别诊断价值

目的评价磁共振弥散加权成像(DWI)及表观弥散系数(ADC)值在脑脓肿与坏死囊变性胶质瘤鉴别诊断中的作用。方法8例脑脓肿和15例坏死囊变性胶质瘤,均行常规磁共振T1WI、T2WI和DWI检查。观察病变区信号强度,并分别测量脑脓肿、胶质瘤坏死囊变区、周围水肿、对侧正常脑白质及脑脊液的ADC值。结果DWI上所有脑脓肿均呈高信号,而胶质瘤坏死、囊变部分均呈低信号。脑脓肿与胶质瘤坏死囊变区ADC值之间,脑脓肿周围水肿与胶质瘤周围水肿的ADC值之间均有统计学差异。结论DWI与ADC值测量能有效反映脑脓肿与坏死、囊变性胶质瘤的不同液态性质,对其鉴别诊断有重要作用。     

功能性磁共振弥散加权成像在急性脑梗死诊断中的应用价值

目的探讨功能性磁共振弥散加权成像在急性期脑梗死患者的临床诊断中的应用价值。方法回顾分析2012-08—2013-04我院接收的80例急性脑梗死患者的临床资料,应用神经解剖法和功能性磁共振弥散加权成像等技术对患者的病变部位行定位和诊断。结果功能性磁共振弥散加权成像的图像显示,急性期脑梗死患者的患侧表观弥散系数为0.389±0.092,健侧的表观弥散系数为0.955±0.112,并呈高信号,而弥散系数的图像则显示为低信号。在急性期,患者病灶的表现弥散系数与相对表现弥散系数均为下降,在慢性期则呈现出升高的趋势。结论 6h内功能性磁共振弥散加权成像技术在脑梗死的临床诊断中的效果要显著优于传统的MRI技术。     

磁共振弥散加权成像对急性脑梗死的诊断价值

目的:探讨磁共振弥散加权成像(DWI)对急性脑梗死的诊断价值.方法:对26例急性脑梗死患者(发病＜6h4例、6-24h14例、1-7d8例)进行常规MRI(T,flair,T2WI,T2flair)检查以及DWI检查,并由计算机算出表观扩散系数(ADC)图.结果:发病＜6h的4例患者常规MRI未见异常;DWI均出现高信号;ADC均为低信号.发病6h-7d的22例患者MRI T2 WI均为高/稍高信号,T1 flair均为低/稍低信号;DWI均为高信号;ADC均为低信号.结论:DWI能在超早期显示急性脑梗死的病灶,对急性脑梗死有着非常重要的诊断价值.     

磁共振扩散加权成像在脑脓肿与脑内囊性肿瘤鉴别诊断中的价值

目的探讨磁共振扩散加权成像(DWI)以及表观扩散系数(ADC)在脑脓肿(BA)与脑内囊性肿瘤(BCT)鉴别诊断中的价值。方法收集经确诊的21例BA和33例BCT患者,所有病例行常规MRI及DWI检查,测量BA与BCT囊变区的ADC值。结果 21例BA患者在DWI上均呈不同程度的高信号,平均ADC值为(0.62士0.18)× 10~3mm~2/s;33例BCT患者中30例在DWI上呈低信号,另3例呈等信号,囊性肿瘤的平均ADC值为(2.37±0.34)× 10~3mm~2/s。BA与BCT的平均ADC值比较差异有统计学意义(P=0.000)。结论 DWI与ADC值能有效区分BA与BCT病灶内囊液的水分子扩散差别,对BA和BCT的鉴别诊断具有重要价值。     

MRI弥散加权成像(DWI)诊断急性、亚急性脑梗塞及相关定量参数的应用

目的:总结我院2003～2004年间急性、亚急性脑梗塞病16例患者的MRI弥散加权成像(DW1)的表现,与 T2WI及T2WI FLAIR序列进行比较,并对感兴趣区进行ADC(表观弥散系数)值测量,推测梗塞灶的面积。方法:急性、亚急性脑梗塞病例16例,其中4例为4小时内检查发现,行急诊溶栓;8例为24小时内检查;2例为3天后一周内检查发现。临床表现12例为脑卒中症状,另外,1例为术后甲状腺危象患者抢救成功后检杳发现脑梗塞病灶,2例颈椎病症状、1例病人以急性心梗入院,入院后检查有亚急性脑梗塞灶。结果:诊断急性、亚急性梗塞病灶24个,基底节区5个,放射冠区4 个,半卵圆中心区2个,小脑半球3个,脑干4个,同时或分别累及颞顶枕叶共6例。其中5名患者为多次发生梗塞,通过 DWI确定责任病灶7个。在放射冠区、小脑、及枕叶病灶明显,基底节区部分病灶显示欠佳,可能与病灶面积较小有关。 T2WI发现病灶5个,T2WI Flair发现病灶6个。TIWI显示病灶数为0个,结论:DWI对诊断急性脑梗塞以及鉴别新旧脑梗塞、确定责任病灶上有较高价值;ADC值的测量对诊断及推断缺血区面积有参考意义;而不同b值(弥散梯度因子)对诊断没有明显的影响。     

早期脑梗死的临床与磁共振弥散加权成像

目的 从临床角度探讨磁共振弥散加权成像（diffusion weighted imagine,DWI)对早期脑梗死的诊断价值和确定DWI在区分常规MRI上所示的多发梗死灶中急性梗死方面的能力。方法 60例脑梗死均进行MRI常规程序及DWI（程度检查,并由4位经验丰富的医师在不了解患者临床体征的情况下进行阅片、记录出病变所在的详细的神经解剖部位,对同一层面所有的磁共振像进行比较,重点分析信号强度的病灶大小。数据经统计学分析。结果 DWI对超急性合肥市急性期脑梗死可显示T2加权像不能显示的病灶,并随时间延长显影范围逐渐增大,在T2加权像上可显示的病灶中,DWI可更清楚、更全面地显示病灶,大于T2病灶。在急性后期,常规MRI及DWI均有较清晰的影像学改变,恢复期及慢性期,DWI影像学逐渐改变变成等信号、杂信号,部分为囊性信号,且不易显示病灶。结论 DWI能非常可靠地显示超急性及急性脑梗死,而在急性后期及慢性期不如T2WI。其具有区分急性和非急性脑梗死的能力。     

脑梗死磁共振弥散加权成像信号改变和近似弥散系数的时间演变规律

目的 :确定脑梗死磁共振弥散加权成像 (DWI)信号改变和近似弥散系数 (ADC)的时间演变规律。方法 :分析 10 1例脑梗死患者的 13 5次DWI资料。结果 :超急性、急性和亚急性期脑梗死DWI为高信号 ,慢性早期多数病灶仍为高信号 ,慢性晚期绝大部分病灶为等或低信号。超急性期、急性期和亚急性期脑梗死ADC下降 ,慢性早期多数病灶接近或高于正常 ,慢性晚期明显升高。结论 :脑梗死的DWI信号和ADC变化具有特征性的时间演变规律 ,结合常规MRI ,DWI可以推断脑梗死所处的时期     

实验性脑脓肿影像学改变的病理基础研究

目的：明确不同时期动物脑脓肿的影像学特征及其相应的病理学改变。方法：制备脑脓肿狗动物模型１４只，采用ＣＴ、ＭＲＩ检查结合多项病理学观测进行动态分析。结果：脑炎期ＭＲＩ对炎症坏死区及水肿范围的显示较ＣＴ扫描更为清晰准确。包膜形成期：ＣＴ上脑脓肿包膜强化是炎症区血脑屏障破坏和新生血管形成所致；ＭＲＩＴ２加权成像上包膜的低信号“暗带”与包膜上的巨噬细胞堆积有关，延迟扫描和ＭＲＩ均能有效地区分脑脓肿的急性脑炎期和包膜形成期，但ＭＲＩ更加准确、迅速。结论：脑脓肿的ＭＲＩ特征与其临床分期及病理学变化的相关性较好，能更加准确、简便、迅速地区别脓肿的脑炎期和包膜形成期，可作为临床诊治脑脓肿的有力参考。     

Neurosurgical management of brain abscesses in children

The authors review the management of brain abscesses (BAbs) in 59 pediatric cases. The major surgical procedure used to treat them was repeated puncture and aspiration (51 cases, or 86.44%), excision (8 cases – 13.56%) being of secondary importance. The main etiology was metastatic lesions (24 cases – 40.68%), those due to cyanotic congenital heart disease being the most frequent. Single lesions dominated (41 cases – 69.49%). Gram-positive cocci were the main bacteria involved (31 cases, 52.5%). CT scan represented the main tool in the diagnosis and follow-up. Puncture and aspiration in BAbs led to a significant decrease in mortality (7 cases – 11.86%), and the incidence of seizures and neurological deficits was also reduced. Mortality was significantly correlated with the following factors: consciousness status, multiple BAbs location and hematogenous dissemination. There were recurrences in 11 cases (18.64%), all observed after aspiration procedures. The current concepts for complex management of BAbs, as reflected in recent literature data, are reviewed, with particular emphasis on the use of real-time CT or ultrasound-guided operative techniques. Received: 8 February 1999     

Regional morphology and biochemistry in experimental brain abscesses

Summary Brain abscesses were induced experimentally in six cats by stereotactic inoculation ofStaphylococcus aureus A8 into the white matter of the left cerebral hemisphere. Seven days later, the brains were frozen in situ with liquid nitrogen and subsequently sawn into coronal sections of 5 mm thickness, while being cooled with liquid nitrogen. Thin slices were taken from those sections containing the largest expanse of abscess: slices of 5 m thickness were stained histologically, and in adjacent 20 m slices the regional distribution of ATP and glucose was mapped using substrate-specific bioluminescence methods. Furthermore, the NADH fluorescence from the surface of the tissue section was recorded.Six layers could be distinguished histologically in the abscess capsule, five of which showed different substrate patterns. Only in two layers a low metabolic activity could be observed, as shown by slight ATP bioluminescence. The pattern of the biochemical substrates in the white matter surrounding the abscess indicated a reduction in the cellular oxygen availability.Supported by the Deutsche Forschungsgemeinschaft, grant no. Pa 266/2/3     

Management of brain abscesses. I: Drainage and antiseptics

Listerian antisepsis opened the way to surgical treatment of brain abscesses, at a time when advances in neurology made it possible to localize many of these lethal infections. William Macewen, a pupil of Joseph Lister, published in 1893 a remarkable monograph on pyogenic diseases of the brain and spinal cord. He recognized that these were caused by bacterial infection, and reported a series of 20 cerebral and cerebellar abscesses, treated by surgical drainage with antiseptic precautions. His mortality was amazingly low, but later surgeons were less successful. The causes of failure included inability to control microbial infection of the brain. Various chemical antiseptics and also serotherapy were tried, but mortality remained very high.     

The use of computed tomography-guided stereotactic techniques in the treatment of brain stem abscesses

A case of a brain stem abscess that was successfully treated using CT guided stereotaxy together with antibiotic therapy is presented. The literature is reviewed and the role of stereotaxy in the treatment of brain stem abscess is discussed.     

Management of brain abscesses. II: Antibiotics and computed tomography

The discovery of the sulphonamides in 1935 was followed by the dramatic introduction of penicillin, first used in the management of a brain abscess in 1942 by J.B. Pennybacker of Oxford. He integrated antimicrobial drugs in a system of diagnosis, local and systemic antibiotics, and operative treatment, which was widely accepted. However, the mortality from brain abscess remained high until the advent of computerized tomography in 1973 made diagnosis safe and easy. During the next two decades, Pennybacker’s system of management was modified, and applied with better results to all forms of brain abscess, including opportunistic infections associated with impaired immunity. These modifications have been studied historically in the management of 140 patients with brain abscesses treated in South Australia in the years 1955–95.     

Incidental findings on brain MRI in a cohort of diabetic patients

ObjectiveTo study the frequency and management of incidental findings in nonenhanced brain MRI of a middle-aged population of type 2 diabetic patients.MethodsWe retrospectively analyzed the results of 289 brain MRI obtained from subjects between 40–75 years recruited from a previous study. Incidental findings were classified into three categories: (1) Vascular findings; (2) neoplastic findings; and (3) others. On the other side, we made a classification of referral findings. To compare our results, we reviewed the prevalence and evidence about management of both incidental and referral findings in other series.ResultsWe found an overall prevalence of incidental findings of 10.4% (30/289). Incidental findings raised according to age. The most common incidental findings were: 7 vascular (2.4%), 6 calcifications (2.1%), 6 cystic (2.1%) and 5 neoplastic (1.7%) lesions. A percentage of 1.7% (5/289) were referral findings which required further clinical work-up.ConclusionIncidental findings are relatively common in patients with type 2 diabetes. The most frequent are vascular findings, accordance with previous studies. Referral findings are uncommon. Clinical evidence about how to best manage the majority of incidental findings is lacking.     

脑脓肿的MRI诊断和立体定向手术治疗

目的 探讨核磁共振(MRI)弥散加权成像(DWI)与表观弥散系数(ADC)值在脑炎病理变化全过程中的诊断价值,进一步评价立体定向脓液抽吸及引流术在脑脓肿治疗中的作用.方法 利用脑炎在核磁共振DWI及ADC值上的表现,对14例23个脓肿灶的磁共振表现进行分析.共行立体定向引导脓肿穿刺及引流手术20例:脓肿穿刺14例,脓肿腔穿刺引流6例.结果 脑脓肿不同期的MRI DWI表现和ADC值有明显不同.20例手术均获得成功,术后头颅CT或MRI复查显示脓肿腔消失.所有病人在随访期内(4个月至3年,平均14个月)未见脓肿复发.结论 脑炎各个时期有其不同的MRI表现,DWI及ADC值已成为脑炎各期诊断的一个重要诊断依据.立体定向脑脓肿穿刺抽吸和引流手术应为脑脓肿的首选外科手段.     

MRI线性测量局部脑萎缩对早期阿尔兹海默病的诊断意义

目的评价ＭＲＩ线性测量脑萎缩程度对阿尔兹海默病（Ａｌｚｈｅｉｍｅｒｄｉｓｅａｓｅ，ＡＤ）患者的早期诊断价值。方法应用ＭＲＩ线性定量测量对３０例轻度痴呆的ＡＤ患者、２０例多发脑梗塞性痴呆（ＭＩＤ）和２０名正常老年人进行局部额叶（双额指数、额叶半球间宽度）、中颞叶（海马钩回间距、中颞叶最小厚度）及海马结构（海马高度、脉络膜裂宽度、海马脑干间距及颞角宽度）等指标测量。结果颞角宽度指标是区别ＡＤ患者与ＭＩＤ患者及正常老年人的最敏感的指标；其敏感性达９０％，特异性达８５％。如结合脉络膜裂宽度、海马高度、海马与脑干间距及海马钩回间距，其敏感性达９３％，特异性达９５％。结论ＭＲＩ线性定量测量局部海马萎缩能够作为早期诊断ＡＤ的准确可靠性指标之一。