The characteristics of cerebral meningiomas and surrounding tissues on dynamic CT

Summary Dynamic CT was utilized to evaluate 11 patients with histologically benign meningiomas. While it was found that all demonstrated macroscopic neovascularity, subtle differences in the dynamic perfusion curves were identified both between different meningiomas and from region to region within the same tumor. Other than basic anatomic differences, these changes may reflect intratumoral ischemia and hypothetically herald cystic/necrotic alteration within the neoplasm. The dynamic calculations over the surrounding brain showed areas of gross hyper- and hypoperfused cerebral cortex, and hypoperfused white matter in regions of peritumoral edema. These latter findings are of uncertain clinical importance. The dynamic examination also confirmed cases of dural venous sinus invasion and calvarial permeation by tumor. In addition, the dynamic series showed macroscopic neovascularity in one case with a completely negative selective cerebral arteriogram. It is felt that certain cases which have previously been evaluated by static CT may benefit from further study utilizing the dynamic method.     

Contrast agents in functional MR imaging

Contrast agents have greatly expanded the role of MR imaging (MRI) to allow assessment of physiologic, or “functional,” parameters. Although activation mapping generally does not require contrast agents, other forms of functional MRI, including mapping of cerebral hemodynamics (eg, perfusion imaging), are best done with the use of contrast agents. Serial echo planar images are obtained after bolus injection of lanthanide chelates. Application of susceptibility contrast physics and standard tracer kinetic principles permits generation of relative cerebral blood volume maps. Deconvolution of cerebral blood flow and mean transit time parameters is also possible within technical limitations. By using diffusion and perfusion pulse sequences, an imaging correlate to the ischemic penumbra can be identified. Functional MRI perfusion imaging of intraaxial tumors is analogous to positron emission tomography for delineation of metabolic activity, yet may be even more sensitive to neovascularity and possesses improved image quality. Clinical applications include biopsy site selection and postirradiation follow-up. Further improvements in data analysis and map generation techniques may improve diagnostic accuracy and utility.     

Neuroradiology of primitive neuroectodermal tumors

Summary The neuroradiological findings in four cases of primitive neuroectodermal tumor of the cerebrum are described. These highly malignant neoplasms of childhood present as large, enhancing cerebral masses with extensive neovascularity. Cerebrospinal fluid seeding is common and distant extraneural metastases may occur.     

瘀血性脑血管病的脑血流灌注改变:初步经验

目的:探讨瘀血性脑血管病(CCVD)的脑血流灌注变化特点。方法:收集2006年~2009年间在我院经MR增强扫描和临床其他检查确诊的CCVD病例13例,其中颅内静脉窦血栓形成(DVT)8例,有脑水肿并发症的脑发育性静脉异常(DVA)5例,伴有静脉性脑梗死6例(均为DVT病例)。脑血流灌注成像采用磁共振动态磁敏感对比增强灌注加权成像(DSC-PWI),原始数据传送至GE AW4.3工作站做图像后处理,得到平均通过时间(MTE)、负性增强积分(NEI)、达谷时间(TTM)和最大下降斜率(MSD)伪彩图。将脑病变分为两组,即静脉性梗死(VI)组和脑水肿(BE)组,比较两种不同病灶的血流灌注参数的异同。收集同期急性动脉性脑梗死(AI)病例9例,用同样方法比较AI与VI病灶血流灌注变化的异同。结果:在CCVD,VI和BE灶的MTE和TTM均增大,两组间差别无显著意义;但NEI和MSD两组间存在显著差异,在VI灶两参数均显著降低,而BE灶则有的升高,有的降低,改变不一致。在VI和AI的对比中,各灌注参数的变化趋势是一致的,虽然AI的MTE延长和NEI降低幅度更大,但统计学上差别无显著意义。结论:在CCVD,VI和BE灶的血流灌注值有显著差异,NEI和MSD的显著降低可能是脑血流灌注失代偿的反映。无论是VI还是AI,其血流灌注参数呈相同的变化趋势,提示脑血流灌注失代偿期的相同结果。     

320排动态容积CT全脑灌注成像技术在脑梗死中的临床应用

目的:探讨320排动态容积CT全脑灌注成像技术在脑梗死诊断中的优势及临床应用价值。方法:对42例脑梗死患者行CT全脑灌注成像,一次对比剂注射得到平扫容积图像、CT血管成像图像及全脑灌注图像,综合运用这三种检查方法全面评估脑梗死。结果:42例脑梗死患者共发现18例存在缺血半暗带(IP),其中8例超急性期6例存在IP,19例急性期8例存在IP,15例亚急性期4例存在IP。42例梗死核心区与健侧对应区比较,脑血容量(CBV)、血流量(CBF)、平均通过时间(MTT)及达峰时间(TTP)值差异均具统计学意义(P<0.05)。18例IP区与梗死核心区比较,CBV、CBF、MTT及TTP值差异均具统计学意义(P<0.05),与健侧对应区比较,CBV值差异无统计学意义(P>0.05)。结论:急性期及亚急性期脑梗死仍可能存在IP。应用320排容积CT全脑灌注成像,对脑梗死患者可明确其责任血管的狭窄部位及程度,了解病变范围及有无IP存在,实现对脑梗死的全面评估。     

MRI of non-ischemic vascular disease: aneurysms and vascular malformations

Due to flow-void phenomena, MRI is of great value in the demonstration of cerebral aneurysms and vascular malformations as well as of related parenchymal changes and hemorrhagic complications. Magnetic resonance angiography can produce vascular images which are of importance in the diagnosis and follow-up of the lesions.     

脑梗死患者血浆中降钙素基因相关肽和内皮素关系的临床研究

目的探讨急性脑梗死患者血浆降钙素基因相关肽和内皮素含量的动态变化及其临床意义。方法用放射免疫分析法（RIA）对23例健康者与39例脑梗死患者血浆中降钙素基因相关肽（CGRP）和内皮素（ET-1）的含量进行对照分析。分析CGRP与ET-1的动态变化及相关性。结果脑梗死患者血浆中的（CGRP）、ET-1含量在1个月内明显高于对照组（r=-0．317，P〈0．05）。在1个月后两者的含量基本恢复到正常组水平。结论CGRP、EF-1的含量与脑梗死密切相关，CGRP、ET-1参与了脑梗死患者机体的病理生理过程，根据2者在脑梗死患者血浆中的变化规律，2者在脑梗死的病程中有拮抗作用。     

三维增强MR脑血管成像技术探讨

目的:探讨三维增强MR脑血管成像技术及其临床应用价值.方法:行脑血管3D-CE-MRA检查46例,对其显示脑血管能力、病变的敏感性与真实性进行分析,并与3D-TOF-MRA比较.结果:3D-CE-MRA显示全脑动脉及细小分支和静脉系统.本组动脉瘤15例(17个),3D-TOF-MRA显示13个,3D-CE-MRA全部显示.脑动脉狭窄17例,3D-TOF-MRA表现动脉中断和闭塞,3D-CE-MRA表现出动脉狭窄.动静脉畸形6例,3D-CE-MRA显示出供血动脉、畸形血管和引流静脉.脑肿瘤8例,3D-CE-MRA能显示肿瘤组织动态增强状态.结论:3D-CE-MRA诊断脑血管病变敏感率、准确率高,具有临床应用价值.     

Moyamoya病脑出血与侧支循环的关系研究

目的 探讨Moyamoya病脑出血与侧支循环的关系。资料与方法 分析37例脑出血型Moyamoya病患者的临床资料及DSA，MRA，MRI和CT结果。结果 全部病例在DSA和MRA像上均显示颈内动脉分叉以上狭窄或闭塞，其中双侧病变25例，单侧12例，在62个病变侧中，53侧基底节区可见异常血管网形成，其中丰富者43侧，较少者10侧，极少或没有者9侧，32个病变侧显示扩张的软脑膜吻合支，后交通动脉增粗23支，眼动脉增粗26支，通过前交通动脉供血5侧，所有造影像上均未见血管造影可显示的动脉瘤，在MRI和CT像上显示基底节脑出血12例，脑叶内出血7例，丘脑出血2例，蛛网膜下腔出血6例，脑室内出血10例，脑出血以突发头痛，神志不清，失语，偏瘫为主要症状。结论 Moyamoya病临床表现与其侧支循环有密切关系，丰富的侧支循环对脑循环起重要代偿作用。可以保护缺血的脑组织；另一方面，如果异常扩张的侧支血管破裂，可引起脑出血，笔者认为Moyamoya病脑出血与其丰富的侧支循环关系密切，基底节，丘脑及脑室出血与脑底异常血管网有关，脑叶内出血可能与扩张的软脑膜吻合支破裂有关，而这两种侧支血管破裂均可引起蛛网膜下腔出血。     

成人外伤性脑梗死的CT诊断

目的 探讨成人外伤性脑梗死的影像特点.方法 分析30例成人外伤性脑梗死的临床与CT资料.结果 脑叶梗死17例,基底节-内囊区梗死13例,伴蛛网膜下腔出血15例,硬膜下血肿9例,硬膜外血肿3例,脑内血肿3例,脑疝5例,出血性脑梗死2例.结论 CT发现成人外伤性脑梗死的最佳时间是外伤后24 h～6 d,梗死多伴有颅脑损伤的其他CT表现,临床结合动态CT观察是诊断成人外伤性脑梗死的有效方法.     

Angiographic abnormalities in progressive multifocal leukoencephalopathy: an explanation based on neuropathologic findings

BACKGROUND AND PURPOSE: Progressive multifocal leukoencephalopathy (PML) is typically occult at angiography and fails to enhance on MR images. After observing angiographic abnormalities characterized by arteriovenous shunting and pathologic parenchymal blush in patients with AIDS-related PML, often in the absence of contrast enhancement on MR images, we hypothesized that there might be distinct changes in the cerebral microvasculature that account for the reduction in vascular transit time (arteriovenous shunting) in the absence of blood-brain barrier dysfunction. METHODS: The imaging studies and neuropathologic specimens of six patients with biopsy-proved PML were reviewed retrospectively. In all patients contrast-enhanced MR imaging and CT, followed by cerebral angiography, were performed before stereotactically directed biopsy. The angiograms were evaluated for the presence of vascular displacement, pathologic parenchymal blush, arteriovenous shunting, and neovascularity. The CT and MR studies were reviewed for the presence of enhancement of the PML lesions. Biopsy specimens were examined for the presence of necrosis, perivascular inflammation, and neovascularity. RESULTS: All patients had oligodendrocytic intranuclear inclusions diagnostic of PML, together with perivascular inflammation and neovascularity to a varying extent; no other neuropathologic processes were identified. Angiographic abnormalities, characterized by a pathologic parenchymal blush and arteriovenous shunting, were identified in four of the six patients. In only one of these cases, however, was abnormal enhancement identified on cross-sectional imaging studies (MR and CT), and this patient had florid perivascular inflammatory infiltrates histologically. CONCLUSION: The pathologic parenchymal blush and arteriovenous shunting seen angiographically in some patients with PML reflect small-vessel proliferation and perivascular inflammatory changes incited by the presence of the JC virus in infected oligodendrocytes.     

急性期脑内血肿3.0T MR扩散加权成像表现

目的:探讨3.0T MR设备中平面回波扩散加权成像(EPI-DWI)和表观扩散系数(ADC)图对急性脑内血肿的诊断价值及与脑梗死的鉴别诊断能力。方法:对18例急性期脑内血肿患者行EPI-DWI检查,获得ADC图并与CT及常规MRI进行对比。同期选择发病时间、病变体积相近的急性脑梗死患者18例,比较急性期脑内血肿与脑梗死的MRI表现。结果:所有急性期脑内血肿在EPI-DWI及ADC图上均为混杂信号,尤其是较大血肿;不同大小血肿周边均可见低信号环。所有急性脑梗死病变均未见周边环状低信号。结论:血肿周边低信号环为急性期脑内血肿的特异性DWI表现,可资与急性脑梗死相鉴别。     

3.0T磁敏感加权成像诊断脑梗死后脑出血的价值

目的：探讨3.0T磁敏感加权成像（SWI）对梗死后脑出血的诊断价值。方法：对50例急性脑梗死后疑有脑出血患者行CT检查,同时行MRI常规序列（T2WI、T1WI、DWI）扫描及SWI扫描,对检查结果进行统计学分析。结果：34例患者CT扫描证实为梗死后脑出血,SWI诊断脑出血34例,T2WI诊断19例,T1WI诊断21例,DWI诊断25例。SWI、T2WI、T1WI和DWI诊断梗死后脑出血的敏感度分别为100.0%、59.0%、61.4%和73.0%,特异度分别为100.0%、65.2%、68.0%和65.3%,阳性预测值分别为100.0%、68.1%、71.0%和75.4%,阴性预测值分别为100%、60.3%、57.2%和78.3%,约登指数（正确指数）分别为1.0、0.24、0.29和0.38。诊断试验秩和比法分析示SWI、T2WI、T1WI和DWI各序列的秩和比值（RSR）分别为1.0、0.3、0.5和0.7。结论：SWI诊断梗死后脑出血比MRI常规扫描序列具有更高的临床应用价值,可作为急性脑梗死及溶栓治疗后常规复查方法。     

Coronary angiography in atrial myxoma: findings in nine cases

We report the findings on selective coronary angiography in nine patients with atrial myxomas. The angiograms were obtained because the patients were suspected of having coronary artery disease. In each case, the diagnosis of myxoma had been made earlier by echocardiography. Coronary angiography in five (55%) of the nine patients showed neovascularity in the tumor without calcification. In one patient, the angiogram showed a varix of the myocardium at the base of the tumor. The angiograms in three (33%) of the nine patients did not show neovascularity but showed tumoral calcification. Six (67%) of the nine patients had significant coronary artery disease that required coronary artery bypass grafting along with resection of the myxoma. These data suggest that the incidence of neovascularity in atrial myxomas is higher than previously reported. Furthermore, a significant number of this older population presented with operable artery disease as well as atrial myxoma.     

Stepwise carcinogenesis of hepatocellular carcinoma in the cirrhotic liver: demonstration on serial MR imaging

PURPOSE: To demonstrate imaging findings of stepwise carcinogenesis of hepatocellular carcinoma (HCC) in cirrhosis at serial state-of-the-art MR imaging exams. MATERIALS AND METHODS: In a retrospective search of the hospital archives, three patients were identified in which developing HCC was observed in serial MR examinations, with histopathology or alpha-fetoprotein (AFP) correlation. Image findings were assessed for signal intensity of the lesions at multiple sequences, including dynamic gadolinium-enhanced imaging. RESULTS: Initial findings in patient A showed a small nodule with fatty infiltration that developed in HCC in follow-up MRI, comprised of low-grade dysplastic nodule (DN; DN I), high-grade DN (DN II), and eventually classic HCC. In patient B, increased signal intensity on T2-weighted images in a single DN among numerous regenerative nodules was the only initial sign. Follow up MRI showed further increase in signal intensity and increased neovascularity, which suggested focal HCC in a DN II. Patient C demonstrated gradually increasing neovascularity as only initial sign, with development of classic HCC over time. CONCLUSION: MR imaging provides insight in various pathways of stepwise carcinogenesis of developing HCC in cirrhosis. This may further explain the genetic heterogeneity, and may facilitate early detection and better selection of patients for follow-up.     

磁敏感成像在脑微出血诊断中的应用价值

目的：探讨磁敏感成像（SWI）对脑微出血的诊断价值,以及对临床利用溶栓药物治疗脑梗死可能出现的脑出血等潜在危险的预见性。方法：66例原发性高血压患者,通过常规T1WI及T2WI检查,根据是否存在脑梗死或腔隙脑梗死分为存在基础病变的高危组（44例）和无基础病变的对照组（22例）。分析两组患者SWI序列显示脑微出血灶的阳性率。结果：所有受检者SWI显示满意。统计分析两组病例在SWI序列中脑微出血灶的个数以及病灶出现的部位。22例对照组中,SWI阳性者为3例。44例高危组中,阳性者为21例。24例阳性患者中,微出血灶出现在基底节区15例,出现在枕、顶、颞、额叶皮层共9例。结论：SWI在检出脑微出血灶方面有明显的优势。对于存在脑梗死等基础病变的高血压患者,SWI显示脑微出血灶的阳性率明显高于单纯高血压患者,可为临床应用溶栓药治疗脑梗死时提供参考。     

Dynamic computed tomography of cerebral parenchymal tuberculomata

Summary The technique of intravenous dynamic cranial computed tomography has been applied to our patient population in Saudi Arabia in which parenchymal tuberculomata make up approximately 10–15% of all cerebral mass lesions. A spectrum of perfusion patterns was observed in tuberculosis progressing from presentation, through treatment, to resolution. These patterns reflect the microscopic vascular evolution of tuberculomata and parallel at least in part the effects of treatment. The method of dynamic scanning further demonstrates its value in improving the specificity of computed tomography in the evaluation of cerebral masses, thereby enhancing patient-beneficial triage.Presented at the 7th Meeting of the Pan African Association of Neurological Sciences: 27–30 April, 1986, Abidjan, Ivory Coast     

低剂量多层螺旋CT 在脑出血及脑梗死复查中的应用价值

目的：探讨脑出血及脑梗死多层螺旋CT 低剂量扫描的图像质量及在随访复查中的应用价值。方法对150例成人脑梗死、脑出血患者行CT扫描,初诊时采用常规剂量组即A组（130kV、240mAs）,复查时使用低剂量扫描条件,管电压使用110kV ,即B组（110kV、150mAs）和C组（110kV、100mAs）。并通过双盲法对三组图像的优良率及噪声值进行评价,比较图像质量。并记录三组图像的CTDIvol值和DLP值,对辐射剂量进行比较。结果 B组和C组的CTDI‐vol值分别为24mGy、16mGy ,分别较 A 组（56、7mGy ）下降约58％、72％,两者之间差异均有统计学意义（ P值均＜0.01）;B组和C组图像噪声值均略高于 A 组,质量评分均无统计学差异（ P ＞0．05）。结论低剂量多层螺旋CT（110kV、150mAs、110kV、100mAs）在成人脑梗死、脑出血复查中可大幅度降低辐射剂量,且所得图像质量能够满足诊断要求。     

磁敏感加权成像在脑内微出血影像诊断中的价值

目的：探讨磁敏感加权成像（SWI）在脑微出血（CMBs）影像诊断中的价值。方法：对232例拟诊脑血管病患者行常规MR头颅平扫T2WI、T2FLAIR、T1WI、DWI序列及SWI序列,对常规序列显示的CMBs数目、敏感性与SWI序列比较并进行统计学处理。结果：28例有脑内微出血,SWI序列共检出CMBs 186个,T2WI序列共检出CMBs 38个,CMBs病灶检出敏感性为20.4%;T1WI序列共检出CMBs 21个,CMBs病灶检出敏感性为11.3%。T2FLAIR共检出CMBs 41个,CMBs病灶检出敏感性为22%,DWI序列共检出CMBs 24个,CMBs病灶检出敏感性为12.9%,多序列CMBs检出数目比较,差异有统计学意义（P〈0.05）;SWI序列与T1WI、T2WI、T2FLAIR、DWI序列CMBs检出敏感性比较,差异具有统计学意义（P〈0.05）;28例中,22例有高血压病史,同时合并出血性卒中患者14例,缺血性卒中患者8例,混合性卒中患者6例。结论：SWI序列对CMBs的检出敏感性高于常规序列,CMBs病灶的检出可以反映脑内微血管病变程度,对脑卒中的治疗及预后判断具有较为重要的临床应用价值。     

螺旋CT血管造影在脑动脉瘤诊断及治疗中的应用—兼与MR血管造影比较

目的探讨无创性的螺旋CT血管造影(SCTA)与MR血管造影(MRA)对脑动脉瘤的诊断价值以及对治疗的指导价值,并对两者作比较.材料和方法28例患者同时行SCTA、MRA、DSA,以DSA作为金标准,对SCTA与MRA作比较.结果(1)23例行SCTA及时间飞跃法(TOF)MRA者,SCTA诊断脑动脉瘤的准确性高于TOFMRA,但差异无显著统计学意义(p＞0.05).(2)SCTA较TOFMRA测量脑动脉瘤的最大径准确性高(p＜0.01),TOFMRA测量值常偏小.(3)SCTA测量的栓塞治疗最佳投照角度与DSA符合率94.7%.(4)动态增强(DCE)MRA的图像清晰度及价值与SCTA相似.结论SCTA对体积小、破裂出血的脑动脉瘤的检出率以及对动脉瘤测量的精确性高于TOFMRA,SCTA可较准确地测量动脉瘤栓塞治疗的最佳投照角度,MRA是脑动脉瘤电解可脱弹簧圈(GDC)栓塞术后随访的较好方法,DCEMRA的实用价值与SCTA相似.