原发性脑淋巴瘤CT与MRI诊断

目的分析原发性脑淋巴瘤的CT和MRI表现,以提高对其的认识,减少误诊。方法回顾性分析17例经手术病理证实的原发性脑淋巴瘤的CT和MRI资料。结果CT和MRI主要表现为：（1）CT平扫示脑内单发或多发的等密度或较高密度瘤灶,肿瘤可沿脑脊液播散;MRI T1WI呈等或稍低信号,T2WI呈等或稍高信号;1例出现坏死及出血;②少部分病例瘤周水肿及占位效应轻至中度;（3）MRI增强扫描大多呈团块状均匀强化;1例环形强化。④除病变主体位于胼胝体膝部和压部外,瘤灶长轴多与颅脑前后径走行平行或大致相同。结论原发性脑淋巴瘤多在大脑深部,明显强化,CT和MRI表现具有一定的特异性,结合CT与MRI影像特点和临床资料综合分析,有可能在术前作出正确诊断。     

脑海绵状血管瘤21例影像诊断分析

目的探讨脑海绵状血管瘤的影像学诊断价值。方法对21例脑海绵状血管瘤的MRI、CT影像特征进行回顾分析。结果 21例均行MRI常规扫描,7例增强扫描,20例共有29个结节状或圆形病灶,分别呈T1加权像(WI)、T2WI高或低混合信号,T1WI稍低信号、T2WI高信号,T1WI、T2WI均高信号,T1WI、T2WI均低信号;1例6个病灶呈散在分布圆点形,T1WI、T2WI均低信号。14例行CT检查,显示17个病灶,均为较高密度病灶或不均匀稍高密度。结论脑海绵状血管瘤的MRI显示信号具有特征性,多数脑海绵状血管廇结合MRI及CT检查可以明确诊断。     

鞍区上皮样血管肉瘤一例

患者 女,71岁.因胆囊切除术后突发肢体无力伴意识障碍4 d入院.体检:浅昏迷,压眶肢体屈曲,不能定位,双侧瞳孔等大,直径约4mm,对光反射迟钝,肌张力正常,病理征未引出.头颅CT示:鞍上池、环池、侧裂、脑室及脑沟内见血性高密度影,侧脑室、第三脑室扩大,鞍上池区见稍高密度灶,并向上延伸至室间孔区.行"锥颅侧脑室引流术",经治疗病情好转.行MRI检查:鞍区见不规则等T1略长T2信号灶,其内及周边见不规则T1WI高信号灶,边界欠清楚.病灶填满垂体窝并部分下移到斜坡后方,向上压迫丘脑及第三脑室致其变形,向两侧侵及海绵窦,左侧颈内动脉被包绕显著.     

颅咽管瘤非典型MRI表现

目的探讨颅咽管瘤非典型MRI表现,以提高对此病的认识。方法回顾性分析4例经手术病理证实的颅咽管瘤的MRI资料。结果4例肿瘤均为囊性:例1肿瘤位于鞍上,瘤内可见脂液平面,脑室、脑池及脑沟内可见大小不等的脂肪小滴;例2肿瘤的大部分位于桥小脑角区,仅小部分位于鞍上,T1WI和T2WI均为高信号,脂肪抑制亦为高信号;例3肿瘤位于鞍上,突向鞍内并延伸至胼胝体压部下方,蝶鞍稍增大,垂体未显示,T1WI和T2WI均为高信号;例4肿瘤位于鞍内及鞍上,蝶鞍扩大,垂体未显示,肿瘤前部T1WI和T2WI均为高信号,后部T1WI信号稍高,T2WI与白质信号相同。结论颅咽管瘤存在方式多种多样,有特征性的MRI表现,也可有非典型MRI表现,肿瘤可向邻近部位延伸,亦可破裂播散至蛛网膜下腔内。囊性颅咽管瘤的信号特点与囊液的成分有关。     

结节性硬化16例影像学诊断分析

目的探讨结节性硬化的CT和MRI表现特点。方法收集16例结节性硬化患者临床、影像及病理资料,回顾分析其脑部CT和MRI表现。结果13例CT检查10例表现为沿侧脑室壁分布的钙化结节,其中多发结节9例,单发结节1例,1例表现为室管膜下等密度结节,2例未见明确异常。11例MRI平扫均可显示室管膜下结节,其中多发10例,单发1例,T1WI结节呈等信号或低信号,T2WI分别呈低信号、等信号或稍高信号;所有结节大小介于2~14mm;MRI同时显示脑皮质及皮质下病变10例。7例MRI增强扫描可见室管膜下结节呈轻中度强化,脑实质内结节多不强化。结论结节性硬化的CT和MRI表现均具有特征性,CT可敏感显示室管膜下结节的钙化,MRI则对CT不易显示的未钙化结节及脑实质内病变更有优势。     

SWI在脑毛细血管扩张症中的临床诊断价值

目的探讨磁敏感成像(SWI)在脑毛细血管扩张症(BCT)的临床诊断价值。方法本研究回顾性分析15例BCT患者的MRI平扫、MRI增强扫描及SWI的直接征象,并对病灶进行计数。结果本组15例患者均行MRI平扫、增强及SWI。BCT在MRI平扫(T1WI、T2WI)、SWI、MRI增强扫描均表现为脑实质内多发低信号,其中SWI检出敏感度最高(100%),其次是增强扫描(39.5%),T1WI,T2WI最低(22.9%,22.6%),SWI检出敏感度与其他序列差异具有显著性(P0.05),增强扫描与平扫检出率具有统计学差异,T1WI与T2WI无明显统计学差异。结论头部MRI平扫、增强及SWI能显示BCT的直接征像,本研究得出头颅SWI成像可作为诊断BCT的首选检查,且是最敏感、最佳的检查方法。     

3例高血糖相关性急性脑损伤患者的临床与影像分析

目的 探讨高血糖导致急性脑损伤的临床特征和影像学变化。方法 分析2例糖尿病伴偏侧舞蹈症和1例糖尿病伴局灶性癫痫的患者,并对3例由高血糖引起的急性脑损伤患者的临床表现、NECT及MR的变化进行总结。结果 3例患者均表现为高血糖及糖化血红蛋白（HbAlc）明显升高,2例表现为偏侧舞蹈症,1例表现为局灶性癫痫;例1为舞蹈症患者,头部CT表现为左侧基底节区高密度灶,头颅MR:T1WI示左侧豆状核高信号灶,T2WI示双侧豆状核低信号、左侧更明显,DWI及ADC序列未见明显弥散受限及高灌注表现,例2为舞蹈症合并脑梗死患者,头部CT表现为右侧尾状核片状低密度影,周围密度增高,头颅MR:T1WI序列显示右侧基底节区有一片状低信号灶（为脑梗死）,病灶周边有高信号灶（考虑高血糖急性脑损伤）,T2WI序列显示右侧基底节高信号,周围为低信号,DWI无弥散受限,例3为局灶性癫痫患者,头部CT未见明显异常病灶,头部MR:T1WI序列示左侧枕叶等信号,T2WI序列可见稍低信号影,而DWI、ADC稍低信号,SWI呈稍低信号。3例患者均经积极降糖及对症治疗后恢复正常。结论高血糖相关性急性脑损伤,患者可表现偏侧舞蹈症及癫...     

原发性中枢神经系统淋巴瘤非典型MRI影像学表现

目的总结原发性中枢神经系统淋巴瘤(PCNSL)非典型MRI影像学表现,以提高对非典型PCNSL影像诊断的正确率。方法回顾性分析经穿刺或手术病理证实的25例原发性中枢神经系统淋巴瘤的MRI影像学表现,包括非典型的生长部位,非特异的MRI表现和强化方式。结果 25例中单发病灶者16例,多发病灶9例,病灶数共38个。不典型发生部位可见于鞍上、脑干、小脑半球和小脑蚓部、侧脑室、三脑室和第四脑室等等。病灶形态大小不一,表现形式多种多样,可呈类圆形、不规则形,团块状、结节状、斑片状、灶状或散在分布。1例病灶侵及邻近脑膜,出现"脑膜尾征"。20例在T1WI呈稍低或等信号,T2WI呈等或稍高信号,5例T1WI、T2WI呈混杂信号。7例呈实性均质强化,6例呈结节状强化,3例呈斑片状强化,2例呈条纹状强化,2例呈环形强化,1例呈弥漫肿胀伴轻度强化,3例多发病灶多种强化方式并存。5例DWI呈均质高信号,6例呈不均匀稍高信号,4例呈中等信号。MRS检查4例出现较明显的Lip峰。结论对于发生在非典型生长部位、影像学表现非特异性的,以及颅内多发病灶的和侵犯脑膜的中枢神经系统淋巴瘤,术前诊断较为困难,需引起高度重视。     

急性CO中毒患者MRI MRA表现

目的评价MRI、MRA对急性CO中毒的诊断及价值。方法回顾分析60例经临床确诊的急性CO中毒患者的头颅MRI、MRA资料。结果MRI异常表现为双侧苍白球、双侧侧脑室周围、脑干、脑叶为主的T1WI高信号、T2WI低信号;18.33%急性CO中毒患者伴发脑梗死,DWI为高信号,ADC为低信号。结论急性CO中毒的诊断主要依靠病史、临床表现和影像检查,头颅MRI、MRA对本病的诊断有一定的价值。     

MRI与CT在诊断原发性脑淋巴瘤中的特点及应用

目的探讨MRI与CT在临床上检查诊断原发性脑淋巴瘤的特点及应用。方法对笔者所在医院近期的13例经病理证实的原发性脑淋巴瘤的MRI、CT资料进行回顾性分析。结果 13例患者中,9例单发者,4例多发者,一共21个病灶。CT平扫多表现为等或稍高密度,而MR平扫时T1WI等或稍低信号,T2WI呈高信号。结论原发性脑淋巴瘤的CT和MRI表现具有一定的特征,对CT与MRI影像资料进行综合分析,对提高早期诊断的正确性具有一定临床意义。     

SWI DWI序列在颈椎手术后并发急性脑梗死脑出血中的诊断价值

目的探讨磁共振磁敏感加权像(SWI)、弥散加权成像(DWI)在颈椎术后并发急性脑梗死、脑出血中的诊断价值。方法 2010-01—2015-12我院行颈椎手术、临床确诊术后并发急性脑梗死37例和急性脑出血14例,采用GE 1.5T磁共振,全部行常规横断位T1WI、T2WI、FLAIR、SWI(磁敏感加权成像)、DWI(磁共振扩散加权成像)扫描,所得影像学资料进行对比分析。结果 37例颈椎术后急性期脑梗死患者,常规MRI序列2例未检出;DWI序列全部检出,其信号表现为均匀的高信号影;SWI表现为等信号,出血继发性转化时,其信号成斑片样低信号影。14例颈椎术后急性脑出血期患者,常规序列、DWI序列1例未检出;SWI全部检出。DWI序列表现为血肿中心呈低信号影,周围环绕稍高信号的水肿区;SWI序列表现为血肿中心区均匀片样低信号,周围环绕高信号水肿区。结论 DWI、SWI较常规颅脑MRI序列可及早、准确的检出早期颈椎手术后并发的急性脑梗死、脑出血,并根据其影像表现不同,行快速诊断及鉴别,对患者的预后有重要意义。     

动脉粥样硬化性大脑中动脉区域TIA功能磁共振成像分析

目的利用弥散加权成像(DWI)、磁共振血管成像(MRA)对大脑中动脉(MCA)区域TIA进行解剖性定位,评价磁共振对临床实践的指导意义。方法对32例TIA患者,在发作1.5h~7d内行头部MRI、DWI、MRA检查,对DWI图像上的高信号与T2WI像、MRA、临床症状、体征进行对照研究。结果2例DWI正常,但MRA颅内大脑中动脉闭塞,病变血管与临床症状相一致。12例DWI正常,MRA仅轻度狭窄或正常。3例DWI有高信号,T2WI无相应病灶为超早期脑梗死,其中MRA1例动脉硬化样改变,2例大脑中动脉闭塞,病灶与体征相符。15例DWI有高信号、T2WI有相应病灶,2例为早期脑梗死、13例为腔隙性脑梗死,其中MRA8例颅内大血管轻到中度狭窄,2例严重狭窄。MRI显示20例(62.5%)存在多发陈旧腔隙性梗死灶。对于TIA患者发作时MRA相应病变进行χ2四格表精确检验,DWI异常组与正常组比较P<0.05,MRA大血管病变是TIA预后形成梗死的独立危险因素。结论对TIA患者行MRI、DWI、MRA检查,能及时发现超早期脑梗死,还能对新发腔隙性脑梗死准确定位,科学指导临床早期干预治疗。MRA可提供1.2级大血管的供血状态,指导后续的2级预防。     

磁敏感加权成像在出血性脑梗死诊断中的初步应用

目的探讨磁敏感加权成像（SWI）诊断出血性脑梗死的临床价值。方法20例亚急性期出血性脑梗死患者分别行常规MRI、扩散加权成像（DWI）和SWI检查,根据图像分析结果比较不同扫描序列所显示的梗死灶内出血灶数目及其阳性检出率;测量SWI序列出血最大层面出血灶面积和T2WI序列梗死灶最大层面的梗死灶面积,并行相关分析;观察SWI序列对梗死灶内静脉血管的显示程度,以及梗死灶以外区域微出血灶的诊断敏感性。结果20例患者SWI序列均显示梗死灶内出血,两名医师共诊断43个出血灶,其中SWI序列显示42个、T1WI序列25个、DWI序列15个、T2WI序列12个;SWI序列阳性检出率与T1WI、T2WI、DWI序列相比,差异具有统计学意义（X^2=51．516,P=0．000）。T2WI序列梗死灶最大层面的梗死灶面积为（18．08±12．47）cm^2,SWI为（5．02±6．27）cm^2,梗死灶面积与出血灶范围之间呈明显正相关（r=0．562,P=0．010）。其中,13例患者SWI序列检出梗死灶以外区域的微出血灶;12例显示梗死灶内小静脉血管分支减少和（或）变细,6例血管增多、增粗和（或）扭曲。结论SWI序列对出血性脑梗死病灶内出血的显示优于常规MRI和DWI序列,并能显示梗死灶内静脉血管的变化及梗死灶以外区域的微出血灶,可作为诊断出血性脑梗死的MRI常规扫描序列。     

High Signal Intensity on T2- Weighted MRI Correlates with Hypoperfusion in Temporal Lobe Epilepsy

Single-photon emission computed tomography (SPECT) and [99mTc]HMPAO were used to assess the functional significance of nonspecific magnetic resonance imaging (MRI) abnormalities observed in patients with temporal lobe epilepsy and no focal lesion on CT scan. We studied 18 patients whose MRI was normal or showed high signal intensity on T2-weighted images (T2WIs) at the site of the EEG focus in 11 and 7 cases, respectively. EEG was monitored during regional cerebral blood flow (rCBF) study. Lateralized hypoperfusion was present in 7 of 17 interictal (41%) and in one postictal cases; it was located in the temporal lobe on the side of the EEG focus in all, and was significantly more frequent in patients with high signal intensity on T2WI (86%) than in patients with a normal MRI (18%). The degree of temporal perfusion asymmetry measured in each individual was higher in patients whose MRI was abnormal.     

Diagnosis of acute cerebral infarction using diffusion-weighted imaging by low field (0.2 T) magnetic resonance image]

The purpose of this study is to confirm the diagnosis of acute cerebral infarction on diffusion-weighted imaging using low field (0.2 T) magnetic resonance image(MRI). Acute cerebral infarctions in 51 patients were examined on diffusion-weighted imaging using low field MRI within 48 hours after clinical symptoms. Diffusion-weighted imaging was examined using line scan method. Twenty-four cases were cortical infarction, and twenty-two cases were perforating infarction. In five cases out of 51 cases, ischemic regions were not detected as abnormal high signal intensity area on diffusion-weighted imaging. Four cases of no abnormal detection were transient ischemic attack, and the other one was a perforating infarction. The earliest detection time in cortical infarction cases was 1 hour and 20 minutes. On the other hand, the earliest detection time in perforating infarction cases was 3 hours. Detective ability for acute cerebral infarction on diffusion-weighted imaging by low field MRI was depending on both size and lesion of infarction. That is to say, either small size or brain stem infarction was hard to detect. Thin slice and vertical slice examination for the infarction may improve to diagnose in low field MRI. Our conclusion is acute cerebral infarction was able to be diagnosed on diffusion-weighted imaging by low field as well as high field MRI.     

纳米磁化标记神经干细胞的MRI大鼠活体示踪实验研究

目的:探讨用MRI活体示踪移植磁化标记神经干细胞在创伤性脑损伤模型大鼠脑内迁移和分布的可行性。方法:建立大鼠脑部左侧半球脑损伤模型。2周后将磁化标记胚胎神经干细胞立体定向移植入大鼠脑部右侧半球。在移植后1、3d及1、2周分别行大鼠头部MRI。结果:移植后行头颅MRI可见移植部位FSET2 WI和GRET2 序列呈环形低信号。实验组大鼠头颅MRI脑内有一低信号线,指向对侧脑挫伤部位。结论:用MRI活体示踪移植磁化标记神经干细胞在TBI模型大鼠脑内迁移和分布是可行的。     

颅内表皮样囊肿20例

目的探讨颅内表皮样囊肿(EC)的临床与头颅MRI影像表现,以便提高诊断率。方法经手术病理证实的20例EC的MRI表现。全部患者均进行了常规平扫序列T_1WI、T_2WI、液体衰减反转恢复序列(FLAIR)及弥散加权成像(DWI)、钆对比剂增强扫描(CE-MRI)检查。结果 20例肿瘤脑桥小脑角池12例(左侧7例,右侧5例),桥前池3例,脑实质内2例(右侧枕叶1例,左侧额叶1例,病灶均发生于皮质区或皮质下区),左侧外侧裂池1例,枕大池1例,四脑室1例。其中4例病灶同时受累桥前池、鞍上池、侧裂池及环池等多个脑池间隙;全部病灶均呈囊性改变;13例长T_1WI、长T_2WI信号,4例T_1WI、T_2WI为混杂信号,3例T_1WI、T_2WI均为高信号;11例T_2FLAIR序列检查结果均呈混杂信号,其内可见散在的絮状稍高信号影,6例为低信号,3例为稍高信号;DWI序列检查结果为19例高信号,1例低信号。结论 EC的MRI表现具有特征性,尤其是FLAIR及DWI序列MRI表现有助于对该病的明确诊断。     

Feasibility of establishing cerebral ischemia models by using aerocyst-blocking bilateral ascending pharyngeal artery of piglets Imaging assessment

BACKGROUND: The cerebral ischemia and ischemia/reperfusion animal models are used to simulate the human cerebrovascular diseases is one of the popular topics of neurological science recently. To study the pathophysiology, pathogenesis, prophylaxis and treatment of ischemic cerebrovascular diseases and to establish the ideal animal model that is the most similar to the human cerebral ischemia, are the topics that the people generally cared about. OBJECTIVE: To evaluate the effects of aerocyst-blocking bilateral ascending pharyngeal artery on the establishment of cerebral ischemia models by using digital subtraction angiography (DSA), magnetic resonance diffusion-weighted imaging (DWI) and magnetic resonance perfusion-weighted imaging (PWI). DESIGN: Repetitive measure animal experiment. SETTING: Zhongshan Hospital Affiliated to Dalian University. MATERIALS: The experiment was carried out in the Animal Laboratory (Provincial Laboratory), Zhongshan Hospital of Dalian Univeristy from January to May 2006. A total of 14 domestic piglets, of 6 months old, weighing 12–15 kg, of either gender, were selected from Animal Experimental Center, Dalian University. Multistar T.O.P digital subtraction angiography machine was provided by Siemens Company, German. METHODS: Aerocyst-blocking bilateral ascending pharyngeal artery was used to establish cerebral ischemia models. And then, Multistar T.O.P. DSA was used for imaging of cerebral vessels before blocking, during blocking and at 0.5 and 2 hours after ischemia perfusion. GE Signa 1.5 T supraconduction magnetic resonance imaging was used for DWI examination; in addition, PWI was used based on focal sites and areas. Otherwise, magnetic resonance imaging (MRI) was used to detect signal changes of T1WI and T2WI in ischemic areas. MAIN OUTCOME MEASURES: Analytic results of DSA, DWI, PWI and MRI. RESULTS: All 14 experimental piglets were involved in the final analysis. ① DSA: The blood flow of bilateral ascending pharyngeal arteries and its branch were blocked at blocking phase, which restored 0.5 and 2 hours after reperfusion. ② DWI and PWI: There were no observable abnormalities in PWI and DWI at pre-blocking. Abnormal increased signals were found on both DWI and PWI at during and post-blocking. There were reduction in ADC and rCBF and delay in rTTP at all time points except pre-blocking. ③ MRI: There were no abnormal signals observable at any time of pre- and post-blocking in T1WI and T2WI. CONCLUSION: It is feasible to establish this kind of animal experimental models, and it can simulate the ischemic state; meanwhile, the existence and extent can be showed directly by DSA, DWI, and PWI.