Bilateral paramedian thalamic infarctions: a CT study

Summary We describe eight patients with bilateral paramedian thalamic infarction on CT scanning. Clinically, these patients had infarctions of either the paramedian thalamus alone or the paramedian thalamus with a variable extension to contiguous structures. A single occlusion may result in bilateral paramedian thalamic lesions because of the common occurrence of a single trunk of origin for the paramedian thalamic arteries.     

血管性痴呆的脑白质异常信号MR临床分析

目的：对血管性痴呆患者MR图像上的脑白质异常信号（WMH）进行体积定量测量的临床分析,并与无痴呆的脑血管病患者进行比较。方法：对18例临床诊断为血管性痴呆的患者和15例脑血管病对照患者间隔一年先后进行两次头颅MPd检查。采用自行设计的自动体积测量软件测量每位患者的初始WMH体积以及随访结束时的WMH体积变化,然后采用独立样本t检验对血管性痴呆组和对照组的初始WMH体积和咖体积变化进行比较。结果：血管性痴呆组初始WNtt体积为28269±28124n玳13,WMH体积变化为4374±4242mm3。对照组的初始WNH体积为11865±10052mm^3,WMH体积变化为1913±2574mm3。两组之间的初始WMH体积差异具有统计学意义（t=2．304,P=0．031）,而WMH体积变化则表现出有统计学意义差异的趋势（t=1．963,P=0．059）。结论：血管性痴呆患者比普通的脑血管病患者存在更加严重的白质病变,并且进展加快。WMH的增加可能认知功能的下降有关。     

MRI of acute cerebral infarcts: increased contrast enhancement with continuous infusion of gadolinium

We compared contrast enhancement on T1-weighted MRI of acute cerebral infarcts after conventional bolus administration and continuous infusion of gadolinium. We examined 12 patients with a history of acute stroke with contrast-enhanced MRI once a week for a 1 month. Only ischaemic lesions were investigated after cerebral haemorrhage had been excluded by CT. Each MRI study included T2- and proton density-weighted sequences for determination of the size and site of the infarct, immediate postinjection T1-weighted imaging after bolus administration of 0.1 mmol/kg gadolinium-DPTA and delayed T1-weighted imaging after additional continuous infusion of 0.1 mmol/kg over 2 h. A total of 42 MRI studies was performed. In the first week after the onset of stroke, most infarcts (8 of 10) did not enhance after bolus administration, whereas all showed distinct contrast enhancement after the infusion. In the following weeks all but two infarcts showed contrast enhancement after bolus administration; after continuous infusion contrast enhancement could be seen in all cases. While contrast enhancement after bolus administration showed the typical gyriform pattern, enhanced areas were more extensive after the infusion and usually covered the entire infarcted area shown on T2- and proton density-weighted images. We presume that the disturbed blood-brain barrier in ischaemic areas favours delivery of contrast medium to the infarcted tissue if it is offered continuously so that a steady state can develop. Received: 8 April 1998 Accepted: 1 September 1998     

Intra-articular ganglion cysts of the knee: clinical and MR imaging features

The purpose of this study was to present clinical and MR imaging features of intra-articular ganglion cysts of the knee. Retrospective review of 1685 consecutive medical records and MR examinations of the knee performed at three imaging centers allowed identification of 20 patients (13 men and 7 women; mean age 35 years), in whom evidence of intra-articular ganglion cyst was seen. Of the 20 ganglion cysts, 5 were found in the infrapatellar fat pad, 10 arose from the posterior cruciate ligament, and 5 from the anterior cruciate ligament. Three of five patients with ganglion cyst in the infrapatellar fat pad had a palpable mass. In 7 of 15 patients with ganglion cyst in the intercondylar notch, exacerbation of pain occurred in a squatting position. On four MR arthrographies, ganglion cysts were an intra-articular round, lobulated, low signal intensity lesion. Five cases of fat-suppressed contrast-enhanced T1-weighted SE images demonstrated peripheral thin rim enhancement. The clinical presentation of intra-articular ganglion cyst is varied according to its intra-articular location. The MR appearance of intra-articular ganglion cyst is characteristic and usually associated with the cruciate ligament or the infrapatellar fat pad. Magnetic resonance arthrography has no definite advantage over conventional MR in the evaluation of the lesion. For intra-articular ganglion cyst in the infrapatellar fat pad, fat-suppressed contrast-enhanced MR imaging could be useful, because a thin, rim-enhancing feature of intra-articular ganglion cyst allows it to be distinguished from synovial hemangioma and synovial sarcoma. Received: 29 June 2000 Revised: 13 September 2000 Accepted: 15 September 2000     

Cortical laminar necrosis in brain infarcts: chronological changes on MRI

We studied the MRI characteristics of cortical laminar necrosis in ischaemic stroke. We reviewed 13 patients with cortical laminar high signal on T1-weighted images to analyse the chronological changes in signal intensity and contrast enhancement. High-density cortical lesions began to appear on T1-weighted images about 2 weeks after the ictus. At 1–2 months they were prominent. They began to fade from 3 months but could be seen up to 11 months. These cortical lesions showed isointensity or high intensity on T2-weighted images and did not show low intensity at any stage. Contrast enhancement of the laminar lesions was prominent at 1–2 months and became less apparent from 3 months, but could be seen up to 8 months. Received: 14 May 1996 Accepted: 6 September 1996     

MRI of paramedian thalamic stroke with sleep disturbance

The paramedian thalamus is believed to play an important role in the regulation of sleep, and disturbances of sleep regulation are known to occur in paramedian thalamic stroke (PTS). We examined 12 consecutive patients with PTS and sleep disturbance by MRI. Two distinct groups of patients could be defined: six presenting with severe hypersomnia (group 1) and six with slight sleepiness (group 2). On MRI, all patients had ischaemic lesions involving the paramedian thalamic nuclei, the centre of the lesions being the dorsomedial and centromedial thalamic nuclei. In group 1 the lesions were bilateral, butterfly-shaped infarcts involving the paramedian nuclei (three cases), or unilateral with an extension into the subthalamic nuclei. In group 2 the lesions were unilateral and limited to the paramedian nuclei, mainly the dorsomedial nucleus. Bilateral lesions can be attributed to a common origin in some cases for both paramedian thalamic arteries and the mesencephalic arteries. Received: 9 July 1996 Accepted: 14 October 1996     

高场强原发性肝癌MR表现及分析

目的：分析高场强下原发性肝癌的MRI表现。方法：收集经手术或尸检病理证实的原发性肝癌MR资料43例，其中巨块型肝癌32例，其中伴子灶3例，结节型5例，小肝癌6例。设备为GE1．5T超导signa advantage MR。应用SET1WI，FSEPDWI，T2WI进行轴位扫描，所有病均行增强扫描。结果：肝癌在T1WI呈高、等、低信号，在T2WI呈高信号，部分肿瘤内部信号不均，肝癌的强化程度主要取决于肿瘤血供的多少，肝癌的包膜由纤维组织构成，表现为低信号环，无包膜的肿瘤门静脉侵犯发生率高，肿瘤的信号及包膜与其病理分级有一定的相关性。结论：MRI对反映原发性肝癌的病理特征有其独特的优越性。     

韦尼克脑病的MRI表现及DWI对临床预后的评价

目的:探讨韦尼克脑病(Wernicke’s encephalopathy,WE)的MRI表现及弥散加权成像(DWI)在临床预后及治疗中的价值。方法:对10例经临床证实的WE患者的MRI资料进行分析,同时DWI检查,8例行MRI复查并对治疗前后病灶表观弥散系数(ADC)值进行比较。结果:5例患者均出现双侧丘脑、第三脑室及导水管周围广泛对称性异常信号累及,乳头体、被盖及四脑室底部异常信号各1例。上述病变呈稍长T1稍长T2信号改变,FLAIR序列呈高信号。DWI显示10例病灶区呈高/稍高信号,5例患者治疗前ADC值减低,其中3例经治疗后复查ADC值升高;另外5例患者病灶区治疗前ADC值无明显下降,治疗后ADC值均升高,患者预后均较好。结论:WE脑病具有典型的MRI表现,DWI对临床诊断及预后评价具有重要意义。     

子宫腺肌症的MRI表现及其病理学对照研究

目的：研究MRI在子宫腺肌症诊断中的应用价值。方法：对30例子宫腺肌症患者行矢状面快速自旋回波（Turbo SE)T1WI,T2TI,T1和T2频谱预饱和翻转恢复序列（T1SPIR和T2SPIR）扫描，必要时辅以横断面或冠状面扫描。所有病例均经手术病理证实。结果：弥漫型子宫腺肌症12例，在T2WI上表现为子宫结合带弥漫性增厚，厚度10－35mm，平均18mm，6例病变呈均匀低信号；6例病变内有散在的点高信号区，其中5例在T1WI仍表现为高信号。局限型子宫腺肌症（腺肌瘤）18例共23个病灶，在T2WI上表现为肌层内卵圆形，不规则形或类圆形肿块，呈与结合带信号相近的低信号，直径2．0－7.5cm，平均3.9cm，除1个病灶与周围肌组织有较清楚的界限外，其余病灶均与周围肌组织分界不清，15个病灶内有散在点状高信号区，其中12个在T1WI上也呈高信号，MRI上弥漫增厚的结合带和局限性低信号肿块，病理学上为异位内膜岛周围增生肥大的平滑肌，其内散在的点状信号区异异位内膜岛。仅在T2WI表现高信号的为示出血的内膜岛，在T1WI和T2WI均为高信号的为出血的内膜岛。结论：MRI是诊断子宫腺肌症的优越的无创性检查方法，T2WI最佳扫描序列，T2WI与T1WI，T1SPIR，T2SPIR4种序列相结合可大大提高断诊准确率。     

侧脑室脑膜瘤的磁共振表现

目的：通过分析侧脑室脑膜瘤的磁共振特征,以提高诊断准确性。方法分析手术病理证实的27例侧脑室脑膜瘤的磁共振资料,总结其磁共振影像特点。结果25例位于侧脑室后角及三角区（其中19例位于左侧、6例位于右侧）、1例位于侧脑室体部、1例为多发。所有肿瘤M RI均表现为边界清楚的肿块影。22例肿瘤形态呈圆形（81．5％）,5例浅分叶（18．5％）,1例深分叶。信号均与脑灰质对比,T1 WI呈等高或稍低信号,T2 W/FLAIR呈等或稍高信号,与脑室外脑膜瘤信号基本一致。T1 WI增强扫描多数为明显强化,并显示肿块边缘与脉络丛相连。肿瘤病理类型：19例为纤维型、8例为上皮型。测ADC平均值分别为纤维型（0．89±0．12）×10-3mm2/s ,上皮型（0．95±0．18）×10-3mm2/s。结论侧脑室脑膜瘤具有一定的M RI征象,可以提高术前诊断的准确性。     

静脉性脑梗死MR影像特点

目的回顾总结静脉性脑梗死MRI及MRV影像表现,旨在提高影像诊断水平。方法对15例静脉性脑梗死的MR表现进行了回顾性分析,其中9例临床治疗后复查MR表现明显好转,临床症状明显改善。15例均行常规MRI平扫,其中9例同时进行MR增强及3DCE-MRV,6例行2DTOF MRV。结果 15例脑内多发病灶9例,单发病灶6例,其中2例脑梗死伴出血改变。15例中发生于额叶4例,顶叶6例,颞叶3例,枕叶1例,小脑1例。静脉栓塞部位11例为上矢状窦,1例直窦及左横窦,1例右侧横窦及乙状窦,2例皮层大脑浅静脉。9例行增强扫描,5例病灶内不规则强化,2例脑膜强化,3例无强化.7例MRV均显示栓塞的静脉血流信号丢失或缺损,3例出现异常静脉侧支或引流静脉异常扩张。结论静脉性脑梗死MR影像表现具有特征性,MRI结合MRV可以作为首选的无创检查方法,对静脉栓塞早期诊断和治疗有重要作用。     

颅内孤立性纤维瘤的MRI表现

目的:探讨颅内孤立性纤维瘤(I-SFT)的MRI表现。方法:回顾性分析8例经手术病理证实的I-SFT的MRI及病理学资料。结果:肿瘤发生在幕下2例,幕上3例(其中侧脑室内1例),跨越幕上及幕下2例,鞍区1例。1例鞍区肿瘤在T1WI、T2WI上呈均匀等信号,其余7例信号不均,T1WI、T2WI上以等、稍高信号为主,其中5例T2WI见小斑片状低信号区,3例见囊变灶,5例病灶内可见粗大流空血管影。MRI增强扫描示8例均明显强化;鞍区肿瘤强化均匀,其余7例强化不均;5例T2WI低信号区明显强化,3例囊变区未见强化,2例可见脑膜尾征。除侧脑室内1例周围脑实质水肿明显外,其余7例无或轻度水肿。病理显示8例均见丰富的小梭形细胞;免疫组化显示CD34(~),CD99(+),Bcl(+),Vimentin(+),EMA(-)。结论:I-SFT的MRI表现有一定的特点,当脑膜肿瘤呈等、较高信号,增强呈明显强化,其内出现粗大流空血管、T2WI低信号区时,可考虑该病诊断,但其确诊仍需依靠组织病理学。     

颅脑磁共振弥散张量成像应用进展

磁共振弥散张量成像技术是利用水分子的弥散运动各向异性进行成像,是目前唯一反映人体活体组织空间组成信息及病理状态下各组织成分之间水分子交换功能状况的检查方法,可以从细胞及分子水平来研究疾病状况。本文回顾DTI的原理和潜在的临床应用,如脑缺血性疾病、脑发育、脑肿瘤、外伤性脑损伤和癫痫、多发性硬化、代谢性疾病等。     

MR imaging assessment of clinical problems in rheumatoid arthritis

Although MR imaging has been increasingly recognized as a useful tool in the diagnosis of early rheumatoid arthritis (RA) and in the assessment of disease activity, these applications have not yet been usually included in the routine management of this condition. Our goal is to review the current role of MRI in the everyday clinical management of patients with RA. The usefulness of MRI in the evaluation of articular and para-articular changes in specific locations, mainly the craniocervical region and the temporomandibular joint, are reviewed. Clinical problems derived from local extra-articular involvement, such as tenosynovitis, "rice-bodies" bursitis, and Baker's cyst rupture, are also described. Finally, we also review the value of MRI in evaluation of some complications of RA such as tendinous rupture, osteonecrosis, stress fracture, and septic arthritis/osteomyelitis.     

Idiopathic granulomatous hypophysitis: clinical and imaging features

Idiopathic pituitary granuloma is a rare disorder similar to lymphocytic adenohypophysitis. Few cases have been reported. We report a new histologically case proven with MRI. The patterns of clinical and radiological presentation and the management of this disorder are discussed. MRI findings suggestive of this condition include an intensely enhancing pituitary mass, associated with dural enhancement. Steroid therapy may be suggested avoiding unnecessary surgery.     

应激性心肌病的临床特征及影像诊断

目的分析和总结应激性心肌病的临床和影像特征，旨在提高对该病的认识。方法71岁女性患者，入院前1d生气后突发胸闷、胸痛伴胸骨后烧灼。先后行心电图、超声心动图、冠状动脉和左室造影、核素心肌灌注（代谢）显像和MR扫描。结果急诊心电图示V1～V4导联sT段抬高和T波倒置，1周后出现病理性Q波，1个月后Q波消失：代之为巨大倒置的T波。心肌酶正常或仅轻度升高。急诊左室造影示左室巨大室壁瘤形成，约占左室容积3／4，左室射血分数（LVEF）约30％，但选择性冠状动脉造影未发现与之对应的冠状动脉病变；1个月后复查造影，示左室室壁瘤明显缩小，左室功能基本恢复，LVEF63．6％。发病1周内心肌核素检查示相应区域灌注和代谢不匹配，提示心肌存活。MRI示左室心尖部巨大室壁瘤形成，但受累节段既无灌注缺损又未见明显延迟强化，提示无坏死心肌。结论极度心理打击发生的短暂性左室心尖球状扩张可称为应激性心肌病。核素心肌灌注（代谢）显像以及MRI心肌灌注延迟显像能够提示病变区存活心肌，可指导临床治疗。     

鳞状乳头型颅咽管瘤的临床、病理及MRI对比分析

目的 研究鳞状乳头型颅咽管瘤的临床、病理及ＭＲＩ表现,并进行对比分析及鉴别诊断。方法 选取经临床及病理证实的鳞状乳头型颅咽管瘤３５例,均行ＭＲＩ扫描,男２２例,女１３例,采用美国ＧＥＳｉｇｎａ１．５Ｔ或０．５Ｔ超人振扫描仪,结果 鳞状乳头型颅咽管瘤在３５￣４５岁发病率最高,２４例有视野改变;２７例位于鞍上,１４例长入第３脑室,肿瘤直径在１２￣５６ｍｍ之间。肿瘤呈呈类圆莆１０例,边缘不规则型或分叶型     

急性播散性脑脊髓炎的临床、病理及CT和MRI表现

急性播散性脑脊髓炎(ADEM)是一种急性脱髓鞘性病变，常继发于感染和免疫接种后，主要累及脑白质，也可累及灰质，其临床表现、脑脊液改变及影像学表现有一定特点，但均无特异性，目前还没有一个很好的诊断标准，与其它病变如多发性硬化(MS)等鉴别困难，最后诊断有赖于临床表现、各种检查及一定时间的随访观察。     

Ultra-high-speed MR imaging

Conventional magnetic resonance imaging (MRI) has been shown to provide excellent morphological images of the body organs, particularly structures undergoing little physiologic motion. Nevertheless, the clinical usefulness of MRI has been hampered by long acquisition times, high cost of scanning because of limited patient throughput, and image artifacts due to patient motion. With recent technical developments, several ultrafast scanning techniques capable of acquiring images in a breath-hold now find their introduction into clinical use. The system improvements are potentially useful for a vast range of applications hitherto not accessible to MR imaging. Among these are functional brain imaging, realtime imaging of cardiac motion and perfusion, fast abdominal imaging, improved MR angiography, and potentially real-time monitoring of interventional procedures. Whereas some ultrafast techniques can be performed on conventional scanners, echo-planar imaging, the fastest currently available data acquisition strategy, requires specially designed hardware. This article provides on overview of the technical advances in the ultrafast MRI and discusses potential applications and the possible future impact on body scanning.Correspondence to: G. K. von Schulthess