脊髓亚急性联合变性的MR I诊断价值

目的 探讨脊髓亚急性联合变性(SCD)的MRI诊断价值.方法 回顾性分析17例经临床证实的脊髓亚急性联合变性患者的MRI表现.均行MRI平扫,其中6例行增强扫描.结果 病变位于颈、胸段脊髓后索(8例)或侧索及后索同时受累(9例),抑制T2 WI显示脊髓后出现线条状或斑片状高信号,T1 WI等或稍低信号;横断面T2 WI呈脊髓内"倒V"形对称性高信号10例,"哑铃"形高信号4例,点状高信号3例.增强扫描均无强化.结论 SCD的MRI表现具有一定特征,MRI对SCD早期诊断具有重要价值.     

MRI在小儿难治性部分癲痫中的应用

作者采用单盲法回顾性评价44例经手术治疗的小儿难治性癫痫者的MRI及其病理特点,并探讨两者的相关性。本组包括男22例,女22例,年龄2～18岁,平均12岁。MRI应用1.5T,行横断面和矢状面成像,条件为层厚5mm,TE20～90msec,TR2000～2500msec。冠状面T1加权象TR/TE=500～800/10～20msec,层厚3～5mm,矩阵256×192;T2加权象TR/TE=2500/20～90msec,部分患者行反转恢复序列(TR/TE1500/20～30msec、IR150～600),MRI显示异常病变时行G—DTPA增强。依据下列标准确定异常病变的是否存在:(1)局灶或弥漫性脑叶萎缩(如颞叶萎缩);(2)局灶或弥漫性脑室扩大;(3)结构性萎缩(海马萎缩);(4)     

亚急性联合变性的脊髓MRI特征

目的分析脊髓亚急性联合变性(SCD)的脊髓MRI影像特征,探讨MRI对SCD的诊断价值。方法回顾性分析临床诊断为SCD患者的临床和脊髓MRI,并复习相关文献进行分析。结果 10例SCD患者MRI均显示颈髓和(或)胸髓后索和侧索T2WI高信号,横轴位呈"八字"征、"圆点"征、"三角"征、"双目望远镜"征以及"小字"征。结论MRI提示脊髓后索和侧索选择性受累是SCD的特征性表现,具有重要诊断价值。     

帕金森病手术相关靶点MRI定位解剖的研究

目的探讨MRI定位帕金森病手术相关靶点的准确性和实用性。方法采用T1序列对76例活体人脑前后连合间径(LI)在MRI上的长度进行测量;采用自旋回波翻转恢复序列和T2序列对10名健康人以LI为扫描基线,行3mm层厚、无间距的矢状位、轴位和冠状位头部MRI扫描,分析帕金森病手术相关靶点的MRI位置、影像学特点。结果76例活体人脑MRI上的LI平均长度为22.90±1.30mm;丘脑底核(STN)和苍白球内侧部(GPi)在MRI上清晰显示,其靶点坐标STN为中线旁开12.01±1.25mm,原点后0.62±1.07mm,AC-PC平面下3mm;GPi为中线旁开19.99±1.48mm,原点前3mm,AC-PC平面下3.20±1.24mm。腹内侧中间核(Vim)为MRI不可见靶点,但可根据AC、PC、AC-PC连线和三脑室进行直观、简便的推算。结论MRI可直接、准确地显示脑内一些帕金森病手术相关靶点。     

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。     

磁共振弥散张量成像在诊断中枢神经系统疾病的初步应用

目的 探讨磁共振(MRI)弥散张量成像(DTI)对中枢神经系统疾病的脑白质改变的诊断价值。方法 对10名健康志愿者和64例神经系统疾病患者(脑血管病31例，脱髓鞘疾病7例，炎症7例，肿瘤10例，变性病和先天性发育不良各2例，脑萎缩3例，其他2例)进行MRI检查，包括常规T1WI,T2WI,T2Flair,EWI以及ETI序列。并分别测量FA值。结果 本组59例(92．1％)可见病变区脑白质纤维束消融，FA值减低；12例(20．3％)可见边界清楚的侵蚀状改变，肿瘤病例均可见病变区域旁的白质纤维束推压和移位。结论 DTI可早期发现白质内的病变。与传统MRI相比，DTI能更好地显示脑白质纤维束的受损和移位。     

56例脊髓亚急性联合变性的临床特征

目的 探讨脊髓亚急性联合变性(Subacute combined degeneration of spinal cord,SCD)的病因、辅助检查、早期诊断等。方法 回顾性分析56例SCD患者的临床资料。结果 14例大量饮酒(白酒≥3次/周,每次≥100 g),13例慢性胃炎,7例饮食差,4例长期素食,3例胃切除,1例口服二甲双胍片超过2年,1例炎性肠病; 病程7 d-84月,平均(11.06±17.06)月; 以肢体麻木无力、行走不稳为常见症状,以精神异常、认知障碍等为少见症状; 以闭目难立征阳性、深浅感觉障碍为主要体征; 17例大细胞贫血,10例正细胞贫血,11例仅平均红细胞体积(Mean Corpuscular Volume,MCV)增高; 17/53患者维生素B12(VB12)水平下降,23/28患者同型半胱氨酸(homocysteine,HCY)水平升高,5/35患者叶酸水平下降; 24/46患者运动速度减退,28/46患者感觉速度减退,15/19患者体感诱发电位异常,3/10患者视觉诱发电位异常,3/7患者听觉诱发电位异常; 颈椎:8/45患者侧索病变,15/45患者后索病变,5/45患者侧索及后索同时病变; 胸椎:6/44患者侧索病变,11/44患者后索病变,3/44患者侧索及后索同时病变; 腰椎:1/4患者病变; 颅脑:8/28患者白质脱髓鞘改变; 随访6个月56.6%患者达到临床治愈,28.3%患者症状不同程度好转,15.1%患者无效。结论 长期服用(尤其2年以上)二甲双胍可能引起SCD,甲状腺功能与SCD是否有关暂不明确; HCY结合MCV及电生理学检查可早期诊断SCD,MRI可协助SCD鉴别诊断; 治疗以控制危险因素,早期、足量、长疗程甲钴胺为主。     

磁共振弥散加权像诊断急性脑梗死临床分析

目的探讨磁共振弥散加权像(DWI)在急性脑梗死诊断中的价值,确定DWI对超急性脑梗死诊断的敏感性和特异性。方法对60例急性脑梗死患者,经CT检查排除脑出血,均应用1.5T超导MR成像设备行DWI和常规MRI扫描。结果60例均证实为脑梗死。(1)13例超急性期(发病后6h以内),其中2~3h3例;常规MRI:T1WI无异常信号,T2WI1例无异常改变。DWI已显示明显高信号。(2)急性期(发病后6~72h)33例,T1WI26例略低信号,T2WI高信号,33例DWI均为高信号。(3)14例亚急性期(发病后4~10d),T1WI均为低信号,T2WI、DWI均为高信号。结论DWI在急性期脑梗死,尤其是超急性期脑梗死(发病6h以内),诊断方面明显优于常规MRI扫描,DWI诊断脑梗死及超急性脑梗死的敏感性和特异性均为100%,从而为科学地指导临床行超早期溶栓治疗,并为临床治疗效果提供评价指标。     

海绵窦侵袭性垂体瘤MRI与病理对照研究

目的 研究MRI对海绵窦侵袭性垂体瘤的诊疗价值及其意义.方法 30例垂体瘤病人,使用1.5T磁共振机,选用自旋回波行矢状位、轴位和冠状位T1WI,轴位或冠状位T2WI,增强后行矢状位、轴位或冠状位T1WI扫描,并与手术病理资料对比分析.海绵窦侵袭采用KnospE的MRI 5级分级标准,符合3、4级的患者视为MRI海绵窦侵袭性垂体瘤.结果 肿瘤多为等T1或长T2信号.增强扫描呈均匀或不均匀强化.15例MRI证实海绵窦侵袭性垂体瘤,术中均证实存在海绵窦侵袭;3例MRI示3级侵袭病例术中未见侵袭.结论 MRI可为术前诊断垂体瘤的侵袭性提供依据,对选择手术方法和制定治疗方案有重要指导意义.     

24例原发性中枢神经系统血管炎患者的MRI表现

目的观察24例原发性中枢神经系统血管炎(PACNS)的磁共振成像(MRI)表现,探讨PACNS的MRI诊断价值。方法对急性期进行了MRI检查的24例经病理证实的PACNS的MRI特点进行了回顾性分析。结果 24例患者中,病灶以幕上多见[19例(79.2%)],最常累及颞叶、额叶、顶叶及基底节区(包括丘脑),分别为13例(54.2%)、10例(41.7%)、8例(33.3%)、8例(33.3%);大部分病灶累及双侧大脑半球[15例(72.5%)],灰质和白质均受累[21例(87.5%)]。MRI上病灶可多发或单发,均为12例(50%)。病灶形态大致可分为四种类型:斑片状、肿块样、脑回状和混合性,分别为12例(50%)、8例(33.3%)、2例(8.3%)和2例(8.3%)。MRI上所有病灶均呈长(稍长)T1WI、长(稍长)T2WI异常信号,增强扫描可见病灶均有强化,FLAIR上均呈高或稍高信号,9例(37.5%)病灶中心呈散点状短T1WI、短T2WI混杂信号。17例行DWI和ADC序列检查者中,9例(52.9%)在DWI上呈高(稍高)信号,ADC上呈等信号或混杂信号影,8例(47.1%)在DWI及ADC上呈等信号。11例行GRE序列检查者,8例(72.7%)可见病灶局部有点状低信号影或病灶周围血管影增粗,余3例未见异常。8例行MRA序列检查者,仅1例发现异常,可见病灶供血区相应血管局部有狭窄。结论本组24例PACNS患者急性期头MRI均有异常,表现多样,病灶以幕上多见,可累及各个脑区,病灶可多发或单发,多数灰白质均受累。其形态可表现为斑片状、肿块样、脑回状或混合性,增强扫描均可见强化,以斑片状或脑回样强化多见。头MRI上病灶多变、灰白质受累、斑片状或脑回样强化等表现对PACNS诊断有一定提示性。     

Hyperintense signal on spinal cord diffusion-weighted imaging in a patient with subacute combined degeneration

Symmetrical hyperintense signals in lateral columns and posterior columns in T2-weighted images is a characteristic finding in subacute combined degeneration (SCD) secondary to vitamin B12 deficiency. Manifestation of SCD on diffusion-weighted imaging (DWI) has not been well characterised till date. We reported a case of SCD with spinal cord hyperintense signals in DWI sequence. We suggest that spinal cord DWI may be a useful magnetic resonance sequence for the diagnosis of SCD.     

Diffuse signal abnormalities in the spinal cord in multiple sclerosis: direct postmortem in situ magnetic resonance imaging correlated with in vitro high-resolution magnetic resonance imaging and histopathology

In this study, we compared direct postmortem in situ (whole-corpse) sagittal spinal cord magnetic resonance imaging (1.5T) of 7 multiple sclerosis cases with targeted high-resolution in vitro axial magnetic resonance imaging (4.7T) and histopathology. On sagittal in situ magnetic resonance imaging, 1 case had a normal spinal cord, 2 had only focal lesions, 3 had a combination of focal and diffuse abnormalities, and 1 had only diffuse abnormalities. All spinal cords showed abnormalities on high-resolution magnetic resonance imaging and histopathology, confirming the existence of diffuse cord changes as genuine multiple sclerosis-related abnormalities while highlighting the limited resolution of in vivo magnetic resonance imaging.     

MR imaging of the spinal cord--with special emphasis on the factors influencing spinal cord measurement]

On MR images the spinal cord is seen differently in size depending on imaging parameters and displaying window; consequently the findings may be interpreted erroneously as swelling or atrophy of the spinal cord. The purpose of this paper was to evaluate factors influencing spinal cord size on images and to determine the optimal condition estimating the size of the spinal cord. At first we selected 4 cases suspected of cervical spinal disorders which had been examined by both MRI and myelography with tomography. Sagittal diameter of the spinal cord was measured on a film and it was significantly different of those three. That is, the measurement value was greater on T1 weighted image (T1WI) and smaller on T2 weighted image (T2WI) than myelo-tomography. To evaluate the effect of imaging parameters, image reconstruction and image displaying window quantitatively, studied were the cadaveric cervical spinal cord and gelatin phantom tube with a diameter of 13 mm and 9 mm placed in a saline-filled plastic tube. The measurement value was significantly greater on T1WI and smaller on T2WI than true size of the objects. Numbers of phase encoding (128 and 256) significantly affected the measurement value, both on T1WI and T2WI, as well. Ringing artifact of high or low signal was observed at the boundary area of the objects and saline (so-called truncation artifact). However, when the window-level of displaying image was raised stepwisely the measurement value was proportionally decreased and it reached to real value when the level was adjusted at the mean MR signal intensity of the object and saline.(ABSTRACT TRUNCATED AT 250 WORDS)     

DWI及MRA在大面积脑梗塞早期诊断中的价值

目的:评价弥散加权磁共振成像DWI和磁共振血管成像MRA对早期大面积脑梗塞的诊断价值。方法:对24例早期大面积脑梗塞的临床和磁共振资料进行分析,全部患者均行DWI及MRA检查。结果:24例早期大面积脑梗塞中,13例急性期CT扫描未检测出确切病灶,DWI扫描全部出现大片异常高信号,病灶检出率为100％。而在常规T2WI检查中,7例为阴性,病灶检出率为69％。MRA发现血管异常24例,表现为供血动脉闭塞,狭窄、硬化。结论: DWI有助于明确早期大面积脑梗塞病变范围,且能区别新旧病灶。MRA能直接显示大面积脑梗塞闭塞的供血脑血管,联合使用DWI和MRA对早期大面积脑梗塞诊断有重要的临床价值,也有利于早期合理的治疗方案制定及预后判断。     

自发性硬脊膜外血肿的诊断和治疗策略

目的探讨自发性硬脊膜外血肿的临床特征、治疗及影响预后的因素。方法对16例自发性硬脊膜外血肿患者的临床特征、手术治疗时机以及手术后神经功能恢复情况进行回顾总结,并结合文献分析影响预后的因素。所有自发性硬脊膜外血肿患者均行MRI检查。结果16例患者的硬脊膜外血肿分别位于下颈段（2例）、颈胸段（6例）、胸段（7例）及胸腰段（1例）。MRI检查T1WI表现为等信号或略高信号,T2WI以高信号为主,其中可见混杂低信号。12例施行手术治疗的患者中10例预后良好;4例保守治疗者中3例神经功能完全恢复。结论脊髓MRI检查是诊断自发性硬脊膜外血肿的首选方法,早期诊断和外科手术治疗是恢复神经功能、提高疗效的关键。手术疗效主要与自发性硬脊膜外血肿患者手术前的神经功能缺损程度和手术间隔时间有关;症状较轻者在密切观察下可予以保守治疗,其神经功能的恢复主要取决于神经功能缺损程度。目的探讨自发性硬脊膜外血肿的临床特征、治疗及影响预后的因素。方法对16例自发性硬脊膜外血肿患者的临床特征、手术治疗时机以及手术后神经功能恢复情况进行回顾总结,并结合文献分析影响预后的因素。所有自发性硬脊膜外血肿患者均行MRI检查。结果16例患者的硬脊膜外血肿分别位于下颈段（2例）、颈胸段（6例）、胸段（7例）及胸腰段（1例）。MRI检查T1WI表现为等信号或略高信号,T2WI以高信号为主,其中可见混杂低信号。12例施行手术治疗的患者中10例预后良好;4例保守治疗者中3例神经功能完全恢复。结论脊髓MRI检查是诊断自发性硬脊膜外血肿的首选方法,早期诊断和外科手术治疗是恢复神经功能、提高疗效的关键。手术疗效主要与自发性硬脊膜外血肿患者手术前的神经功能缺损程度和手术间隔时间有关;症状较轻者在密切观察下可予以保守治疗,其神经功能的恢复主要取决于神经功能缺损程度。     

脊髓多发性硬化的MRI表现与临床对照分析

目的 探讨脊髓多发性硬化(multiple sclerosis,MS)的MRI表现及其与临床的相关性。方法 分析13例脊髓MS患者,对病变的部位、范围及病变处脊髓的形态、MR信号及病变的强化程度进行分析评价并与临床症状进行对照。结果 13例脊髓MS主要发生在颈髓,急性期局部脊髓肿胀,T1加权像病变呈等信号或边缘模糊的稍低信号。T2加权像呈高信号。活动期病灶呈斑片状、环状或弓形强化。反复发作病例、多发病灶其强化多样性,临床症状多变性。结论 脊髓MS有其特征性MRI表现,其与临床有较强的相关性,能为临床诊断和治疗提供可靠的依据。     

MRI shows dorsal lesions and spinal cord atrophy in chronic sensory neuronopathies.

BACKGROUND AND PURPOSE: Sensory neuronopathies (SN) represent a specific subgroup of peripheral nervous system diseases, characterized by degeneration of dorsal root ganglia (DRG) and its projections. We tried to estimate the frequency and extent of spinal cord MRI abnormalities in a group of patients with SN and correlate these with clinical and neurophysiological features. METHODS: We performed spinal cord MRI scans in 16 chronic SN patients. Images were analyzed for the presence of posterior hyperintense lesions on T2WI and cord areas at C3 level were obtained using a previously validated method. A group of 14 healthy controls with similar age and gender distribution was used for comparison. ANOVA was employed for statistical analysis. RESULTS: Posterior T2WI lesions were found in 13 out of 16 patients. Cord areas were significantly smaller in SN patients than controls (84.3 x 97.2 mm(2), P < .05). Atrophy correlated with severity of sensory ataxia and neurophysiologic abnormalities but not with duration of disease. CONCLUSIONS: These findings support volumetric spinal cord MRI as a useful tool in the assessment of chronic SN.     

Spinal Cord Infarction: Clinical and Radiological Features

Introduction: Spinal cord infarction is an uncommon disease varying in its clinical presentation. This study describes the clinical and radiological presentation of spinal cord infarcts in 17 consecutive patients. Material and Methods: Clinical and MR imaging data of 17 patients were reviewed. Inclusion criteria were acute or subacute presentation (peak within 72 hours) and MRI showing typical signal changes on T2WI compatible with spinal cord infarct. Exclusion criteria were clinical or MRI findings suggesting other etiologies. Results: Clinical presentation included dissociative anesthesia, weakness of limbs, back or neck pain, and autonomic symptoms with symptom onset to peak time ranging from few minutes to 48 hours in patients with anterior spinal artery infarct (n?=?16), and weakness and sensory loss in ipsilateral upper limb in patient with posterior spinal artery infarct (n?=?1). One patient presented with “man-in-the-barrel syndrome (MIB).” MRI findings in anterior spinal artery infarcts included pencillike hyperintensities on T2 sagittal (n?=?16, 100%) and “owl eye” appearance on T2 axial (n?=?6, 37.5%) images. Diffusion restriction was noted in 8 cases and enhancement was noted in 2 cases. The posterior spinal artery infarct showed T2 hyperintensity in left posterior paramedian triangular distribution in cervical cord (C2-C7). Follow-up was available for 9 patients (period ranging from 15-41 months). Four patients had a favorable outcome who could walk independently, 1 patient could walk with support, and 2 patients were wheelchair bound. Two patients died. Conclusion: Spinal cord infarction is a rare but important cause of acute spinal syndrome. Typical distribution and appropriate imaging can help in timely diagnosis.     

High resolution Magnetic Resonance Imaging of the rat spinal cord

Abstract

A two turn saddle shaped surface coil receiver was developed that allowed high resolution magnetic o resonance imaging of the rat spinal cord. This is particularly important in laboratory animals where central nervous system regions of interest are relatively small. A continuous copper wire 1.5 mm in diameter was wound into two turns 28 mm in diameter. The saddle shape of the second turn improved the homogeneity of the signal within the region of interest and maintained sufficient field of view and depth of penetration. The quality factor (Q) for the surface coil was Q= 199 unloaded, and Q=60 loaded. Using this surface coil with a GE CSI II 2.0 Tesla small bore magnet, spin echo T1 (TR= 500 msec, TE=25 msec) and T2 (TR=2000 msec, TE= 100 msec) weighted images were obtained in cross section, using 2 mm slice thickness with 2 excitations per phase encoding step. A sagittal gradient echo (rapid scan, TR=85 msec, TE= 10 msec) was used to document reestablishment of vascular flow following ischemia. Spinal cord ischemia was induced by 14 minute temporary occlusion of spinal cord blood supply. MRI was performed at 18 hours following ischemia. There was a 1.4 fold increase in T2 image intensity in ischemic rat spinal cord (\i = 4), consistent with edema formation, compared to normal rat spinal cord (n = 4). Preliminary studies show that similar high resolution images can be performed on the rat brain. This technique uses standard MRI equipment and the surface coil is made from inexpensive readily available materials. There are various animal models of cerebral and spinal cord injury that would benefit from improved high resolution MRI. This coil design may have application in larger animal models and the clinical setting. [Neurol Res 1996; 18: 471-474]     

Increasing the sensitivity of MRI for the detection of multiple sclerosis lesions by long axial coverage of the spinal cord: a prospective study in 119 patients

Diagnostic imaging criteria of multiple sclerosis (MS) include the spatial and temporal dissemination of cerebral and/or spinal cord lesions. Magnetic resonance imaging (MRI) is the method of choice for initial diagnosis and follow-up disease monitoring. Current guidelines for spinal MRI recommend sagittal imaging of the spinal cord and lesion confirmation on axial planes if lesions are detected. Sagittal imaging is, however, hampered by technical (e.g. partial volume effects, motion artifacts) and anatomical (e.g. scoliosis) limitations. We hypothesized that long coverage of the spinal cord by axial image acquisition has superior diagnostic performance compared to sagittal imaging and can identify otherwise undetected lesions. Our prospective clinical study included 119 MS patients. Axial MRI revealed ~2.5-fold more lesions than the sagittal angulation (axial lesion load: 4.0 ± 2.4 vs. 1.6 ± 1.2 lesions on sagittal planes, p < 0.001). Importantly, 20 patients (17%) with normal sagittal MRI scans had unequivocal lesions only visible on axial planes (mean lesion number on axial planes in these patients: 2.0 ± 1.3). Moreover, 45 patients (38%) showed a discrepancy of ≥3 lesions that were found additionally on axial scans (mean difference 4.4 ± 1.7). Additionally identified lesions were on average smaller in size and located more laterally within the spinal cord. No lesion on sagittal images was missed on the axial angulation. Our study demonstrates that imaging of small axial segments for lesion confirmation is insufficient in spinal imaging. We recommend implementing a long coverage axial MRI sequence for spinal imaging of MS patients.