小脑梗塞的MRI与临床表现的相关性研究

目的：探讨小脑梗塞的ＭＲＩ征象及其与临床表现的相关性。方法：观察３４例小脑梗塞的临床表现,盲法判断ＭＲＩ表现并与临床对照。结果：临床按病情不同将小脑梗塞分三组,即Ⅰ型（良性型）,Ⅱ型（假肿瘤型）和Ⅲ型（昏迷型）。ＭＲＩ表现亦分三组即显示小梗塞灶（病变范围小于２０ｍｍ）;大梗塞灶（病变范围＞２０ｍｍ）;显示小脑梗塞合并脑干梗塞。ＭＲＩ征象与临床表现的Ｋａｐｐａ值为０．９４７。结论：小脑梗塞的ＭＲＩ征象与各型临床表现密切相关,ＭＲＩ的不同表现可以反映相应的临床过程,是判断临床分型的重要手段     

Gd-DTPA增强MRI对脑梗塞的诊断价值

目的：评价 Ｇｄ － Ｄ Ｔ Ｐ Ａ 在脑梗塞定性诊断中的应用价值。方法：对４０ 例脑梗塞患者进行回顾性分析, 所有病例均行 Ｍ Ｒ 常规平扫及增强扫描,并对增强前后的病变进行定性分析。结果：增强前有１ 例（ ２ ．５ ％ ） 未发现病变,１８ 例（４５ ．０ ％ ） 病变表现不典型,与肿瘤难以鉴别,２１ 例（５ ２ ．５ ％ ） 能够确诊为脑梗塞;增强后１００ ％ 均确诊为脑梗塞。大脑半球的梗塞多呈脑回样强化, 小脑、丘脑、脑干等部位的梗塞则以不规则环行强化及较均匀的点片状强化为主。病变强化的最早时间为１ ｄ ,最晚为１ 年２ 个月。７５ ．８ ％ 病例强化呈逐渐增强趋势。结论： Ｇｄ － Ｄ Ｔ Ｐ Ａ 增强 Ｍ Ｒ 可以提高脑梗塞的确诊率,并能早期发现脑梗塞, 对指导临床治疗有一定积极的意义。     

胼胝体变性的CT和MRI分析

分析胼胝体变性的ＣＴ和ＭＲＩ征象。材料与方法：４例胼胝体变性中，３例为急性发病，１例呈慢性过程，４例均头颅ＣＴ扫描，２例行ＭＲＩ检查，其中１例同行ＭＲＩ增强扫描。结果２例ＣＴ示胼胝体膝部和压部呈片状低密度病变，２例病变仅见于膝部。病变的膝部（３例）和压部（２例）呈膨胀性改变，其中１例发病１６天后，ＭＲＩ平扫和强化未见膨胀性改变和异常强化。结果：（１）ＣＴ和ＭＲＩ是诊断胼胝体变性的有效方法，ＭＲＩ显     

脊柱结核的MRI评价

目的：分析脊柱结核的ＭＲＩ特征。材料和方法：总共１８例证实为脊柱结核的患者行ＭＲＩ检查（男１２例，女６例，年龄１９－７６岁）。结果：ＭＲＩ所见：（１）相邻椎体受累１６例（８８．９％）。（２）韧带下及椎旁脓肿１２例（６６．７％）。（３）椎管内侵犯５例（２７．８％）。（４）１８例共４４个椎体受累，在Ｔ１加权上呈低信号（３４／４４），Ｔ２加权上呈高信号（３２／４４）。（５）１８例中有１６例见椎间盘异常（形态或信号），受累椎间盘在Ｔ２加权上信号多变。结论：脊柱结核的ＭＲＩ征象对诊断极有帮助并能为外科手术提供详细的解剖资料。     

FLAIR序列对脑梗塞的诊断价值

目的：探讨长回波时间的液体抑制反转恢复脉冲序列（ＦＬＡＩＲ）对脑梗塞的诊断及鉴别诊断价值。材料和方法：对２１例经常规ＭＲＩ诊断为脑梗塞的患者进行ＦＬＡＩＲ序列成像，并与ＳＥ序列Ｔ２加权像比较。结果：在２１例脑梗塞病例中，ＦＬＡＩＲ显示病变较Ｔ２加权像清楚明确的１７例（占８１．０％）。Ｔ２加权像难以发现病灶的（＞１个）１５例占７１．４％。结论：ＦＬＡＩＲ序列对脑梗塞病变的显示具有更高的敏感性。特别适合于发现大脑半球表面、基底池周围、灰白质交界及脑室旁区的微小病变。且对梗塞病灶的分期、脑表面梗塞灶与蛛网膜下腔扩大，囊肿的鉴别有帮助。     

弥散加权MRI在脑梗塞诊断中的初步应用

目的：探讨弥散加权ＭＲＩ（ＤＷＩ）对早期脑梗塞诊断的敏感性和对急性与非急性脑梗塞的鉴别诊断价值。材料和方法：３１例脑梗塞（４例超急性,７例急性,１２例亚急性,８例慢性）患者行头颅单次激发回波平面弥散加权ＭＲＩ和常规ＭＲＩ扫描。结果：超急性、急性和亚急性脑梗塞在ＤＷＩ上均表现为高信号,其中４例超急性脑梗塞常规ＭＲＩ阴性。慢性脑梗塞除１例（发病１５天）ＤＷＩ表现为高信号,其余表现为混杂信号、等信号或低信号。６例患者常规ＭＲＩ显示多发脑梗塞灶,但ＤＷＩ显示１个急性高信号病灶。结论：ＤＷＩ对急性脑梗塞,尤其是超急性脑梗塞较常规ＭＲＩ具有更高的敏感性;ＤＷＩ还可以鉴别急性和非急性脑梗塞。     

烟雾病磁共振成像和血管成像表现

目的：分析和讨论烟雾病的ＭＲＩ和ＭＲＡ表现及其诊断意义。材料和方法：对１５例烟雾病患者进行了ＭＲＩ检查，其中１４例同时进行了ＭＲＡ检查。结果：烟雾病ＭＲＩ表现为闭塞血管流空效应消失，侧支循环血管形成，其典型表现为从鞍上向基底节区走行的条状迂曲低信号（７／１５），以及由于缺血和出血引起的改变，包括多发脑梗塞（１１／１５），脑萎缩（７／１５），脑室扩大（４／１５）及脑内血肿和蛛网膜下腔出血（各１例）。ＭＲＡ可直接显示狭窄和闭塞的血管，多表现为多支、双侧血管受累；血管改变有广泛性和局限性两种类型。侧支循环血管表现为基底节区团状模糊血管，呈烟雾状（８／１４）。结论：ＭＲＩ和ＭＲＡ可以显示烟雾病的脑内病理和血管改变，为该病提供了一种安全、准确的诊断方法。     

脑内单发转移瘤22例MRI诊断分析

脑内单发转移瘤２２例ＭＲＩ诊断分析武警总医院神经外科（北京１０００３９）杜长生，张蕴增，毛更生，刘勇，刘雪飞，唐红脑内转移瘤以多发最常见，单发者约占１／４，本文对２２例单发脑实质内转移瘤的ＭＲＩ表现进行回顾性分析，为临床早期诊断提供依据。１临床资料本...     

小脑卒中的MR表现及价值（附36例分析）

本文报告３６例小脑卒中，其中梗塞３０例，出血６例。本组临床诊断率１９％，ＣＴ诊断率２６％，ＭＲ均做出正确诊断。小脑梗塞最易发生在小脑后下动脉供应区，常合并幕上脑梗塞、脑干梗塞及脑萎缩。ＭＲ的典型表现为Ｔ１加权像呈低、Ｔ２加权像呈高信号强度灶。小脑出血在亚急性期呈特征性的分层结构。     

大脑中动脉狭窄相关的脑梗塞20例临床分析

目的：分析了２０例大脑中动脉（ＭＣＡ）狭窄相关的脑梗塞患者的临床中风模式与神经影像（ＣＴ／ＭＲＩ）特点。方法；对经颅多普勒超声（ＴＣＤ）等确诊的２０例ＭＣＡ狭窄的脑梗塞患者进行临床与神经影像的对比分析，结果：２０例中，腔隙综合征１０例（５０％），ＣＴ／ＭＲＩ显示无病灶２例（１０％），基底节和内囊腔隙性脑梗塞８例（４０％）非腔隙综合征１０例（５０％），ＣＴ／ＭＲＩ显示ＭＣＡ皮层无梗塞９例（４５％），     

Cerebral infarction: early detection by means of contrast-enhanced cerebral arteries at MR imaging

The authors describe a new magnetic resonance (MR) imaging sign of acute cerebral ischemia/infarction. Abnormally contrast material-enhanced curvilinear structures were demonstrated in eight patients in the evolving area of cerebral ischemia/infarction within 26 hours after the ictus on contrast-enhanced, high-field-strength (1.5-T), T1-weighted spin-echo images. The abnormal enhancement is considered to represent cortical arterial vessels of markedly slowed circulation in areas of underlying brain injury, which will eventually progress to frank brain infarction. This was demonstrated at computed tomographic (CT) and follow-up MR examinations. Characteristically, the degree of the contrast enhancement of vessels appeared most intense in the proximal portions, and the intensity of enhancement gradually diminished in the more distal portions of these vessels as they pass over the convexities and finally disappear.     

Early cerebral infarction: gadopentetate dimeglumine enhancement

Gadopentetate dimeglumine was administered prospectively to 50 patients who presented for magnetic resonance (MR) imaging within 2 weeks after a cortical cerebral infarction. Twenty-two patients (44%) were imaged within 3 days after clinical ictus. Abnormalities detected with gadopentetate dimeglumine enhancement were observed in 46 (92%) of 50 patients. Classic parenchymal enhancement was a late finding, observed in all patients (17 of 17) imaged at 7-14 days after infarction. Before this time, three additional phases of contrast material-related abnormalities were observed. Enhancement of vessels supplying the infarct ("intravascular enhancement sign") was the earliest finding, seen in 17 (77%) of 22 infarcts aged 1-3 days. From day 2 to day 6, abnormal enhancement of meninges adjacent to the infarct was frequently noted ("meningeal enhancement sign"). Finally, a transition phase that combined intravascular or meningeal enhancement with early parenchymal enhancement was seen from day 3 to day 6. Gadopentetate dimeglumine-enhanced MR imaging in early stroke reveals evidence of vascular engorgement and sluggish flow, which precede the development of classic parenchymal enhancement.     

The cerebral intravascular enhancement sign is not specific: a contrast-enhanced MRI study

The intravascular enhancement (IVE) sign, also known as the “arterial enhancement sign”, is an abnormal finding in the brain on contrast-enhanced MRI studies. IVE has been described in arterial cerebrovascular disorders, most commonly in acute or subacute arterial ischemic infarcts. However, the specificity of this sign has not been established. We describe four patients with disorders other than arterial strokes in whom gadolinium-enhanced high-field (1.5 T) MRI suggested IVE. The conditions were herpes simplex viral encephalitis, idiopathic cerebellitis, pneumococcal meningitis, and superior sagittal sinus thrombosis with venous infarction. IVE in these cases may be due to multiple factors, including arterial, venous, perivascular, and leptomeningeal or sulcal contrast medium accumulation. Our observations suggest that arterial ischemia, previously described as the cardinal cause of IVE, probably does not explain all instances, and urge caution in interpreting this sign as a specific MRI manifestation of acute arterial infarction or ischemia. Received: 28 October 1997 Accepted: 24 June 1998     

颅脑MRI在老年急性眩晕患者诊断中的应用价值

目的：探讨颅脑MRI检查在老年急性眩晕患者中的诊断价值。方法：回顾性分析我科眩晕门诊就诊的老年急性眩晕患者共136例,年龄60-85岁,平均年龄72．5岁。所有患者均以眩晕为首发症状,在眩晕发作后的1-7天内行MRI检查。对阳性发现进行统计分析。结果：老年急性眩晕患者共136例,MRI检查异常发现共33例,占24．3％。其中包括腔隙性脑梗死19例,脑干梗死5例,小脑梗死4例,脑萎缩2例,听神经瘤2例,小脑出血1例。在以单纯眩晕为表现的28例患者中,5例（17．9％）患者MR／可发现异常,包括小脑梗死1例,脑干梗死1例,多发腔隙性脑梗死3例。结论：老年急性眩晕患者颅脑MRI约1／4患者可发现异常。MRI能够提高老年眩晕患者中枢性眩晕的识别率,尤其对以单纯眩晕发作为临床表现的患者,有利于早期诊断,避免漏诊、误诊。     

多模态MRI异常血管信号对急性缺血性脑梗死大脑中动脉大血管严重狭窄及闭塞的对比研究

目的 探究急性缺血性脑梗死患者多模态MRI异常血管信号表现,比较其预测颅内大脑中动脉(MCA)大血管严重狭窄及闭塞的诊断指标.方法 回顾性分析单侧MCA供血区急性缺血性脑梗死患者45例,发病时间小于72 h,患者入院完成常规MRI、磁敏感加权血管造影(SWAN)、扩散加权成像(DWI)、三维动脉自旋标记(3D-ASL)...     

MR contrast enhancement in brainstem and deep cerebral infarction.

MR imaging with IV administration of gadopentetate dimeglumine was performed in 89 patients with 100 clinically and radiologically documented brainstem or deep cerebral (basal ganglia/internal capsule) infarctions to determine the patterns and time course of contrast enhancement. By location, there were 61 deep cerebral, eight midbrain, 23 pontine, and eight medullary infarctions. The age of the infarctions ranged from 1 day to 3 1/2 years, with 22% of the patients scanned within 4 days and 43% scanned within 2 weeks of clinical ictus. Abnormalities on T2-weighted images were encountered in every case. Mass effect was seen in 10 infarctions, most commonly noted between days 2 and 6, but persisting to day 20 in a single case. Parenchymal contrast enhancement was seen in 43 cases, occurring predominately between days 2 and 80. By postinfarction day 3 only half the strokes enhanced, although all did after day 6. Intravascular enhancement within the vertebral or basilar arteries was noted in five cases; all were brainstem infarctions imaged during the first week following ictus. Meningeal enhancement adjacent to the infarction was not seen in any case. Our results indicate that MR contrast enhancement of brainstem and deep cerebral infarctions typically occurs over a period from about 3 days to 3 months following ictus. Lack of both parenchymal and intravascular enhancement is thus to be expected for several days after a brainstem or deep cerebral infarction.     

Perfusion MRI in cerebral infarction

Purpose: To investigate the hemodynamic changes in patients with acute cerebral stroke by perfusion MRI. Materials and methods: In 12 patients with acute stroke in the territory of the middle cerebral artery, perfusion MRI was performed. Peak time, mean transit time, regional cerebral blood volume and regional cerebral blood flow were calculated in the infarction, the peri-infarction area and the contralateral hemisphere. Results: In the infarction the mean blood flow was 29 ml/100 g/min, compared to about 40 ml/100 g/min in the peri-infarction area and the contralateral hemisphere. In two patients increased cortical blood flow was found in the infarction due to luxury perfusion. The cerebral blood volume was reduced in the infarction, but significantly increased, to 7.3 ml/100 g, in the peri-infarction tissue. Conclusion: Perfusion MRI allows one to differentiate various patterns of perfusion disorders in patients with acute cerebral stroke. The resulting data may be helpful in describing the pathophysiologic mechanisms of compensation.      

MRI of brain infarction

MRI of twenty patients with cerebral infarction were reported with their X-CT. MRI with long SE mode clearly showed the ischemic lesion at 18 hours after insult, whereas X-CT performed immediately after MRI scanning showed no abnormality. The signal contrast of the lesion with long SE mode seemed to increase slightly during the patient's course, for a period of several months. The MRI images with long SE at the chronic stage were varied: small lesions appeared as hot areas, whereas large lesions appeared as cold areas and were accompanied with signal enhancement in the surrounding areas. A phantom study was also performed and it was determined that MRI was superior to X-CT in its ability to detect tissue water. One of the reasons for the high diagnostic capability of MRI for acute stroke was, therefore, attributed to this experimental result.     

24 小时内缺血性脑梗塞的CT 研究

通过回顾性分析病程在２４小时因性脑塞患者的ＣＴ片,对其早期ＣＴ征象进行评价,以提高对该病的早期诊断水平。方法回顾性分析经临床确诊的２５０例２４小时内脑梗塞及１００例正常人的ＣＴ表现,评价致密动脉征,豆状核征,脑岛带征,占位征,低密度灶,皮质征等ＣＴ表现。