扩散张量成像在周围神经病变的研究进展简

扩散张量成像是fMRI的重要组成部分,是目前唯一可在体显示白质纤维束的无创性检查方法。此外,还可通过测量各向同性和各向异性等参数,对白质纤维束的完整性进行评价。目前,已有研究将扩散张量成像技术应用于周围神经系统疾病,本文拟从急性周围神经损伤、慢性周围神经损伤,以及周围神经系统炎症和肿瘤等方面对其在周围神经系统疾病的研究进展进行概述。     

脑梗死后锥体束华勒变性的弥散张量成像

目的 应用弥散张量成像(DTI)探讨脑梗死后锥体束华勒变性(WI))弥散参数的变化规律及其早期变化与神经功能的关系.方法 选取2006年3月至2007年1月收入我院神经内科病房的急性(发病7 d内)脑梗死患者15例,男性13例,女性2例.于发病后7 d内、14 d分别进行DTI检查和美国国立卫生研究院腩卒中评分(NIHSS)、日常生活能力指数(BI)、修正的Rankin评分(mRS)、运动功能指数(MI)等神经功能评分.用西门子Trio 3.0T MR机采集DTI数据,由DTI Studio软件处理分析数据.计算出平均弥散系数(MD)、部分各向异件(FA)、第一本征值(λ1)、第二本征值(λ2)和第三本征值(λ3)的参数图.结果 发病14 d时的神经功能评分,NIHSS:6.93±3.39,BI:45.33±26.01,mRS:4.33±0.90,MI:69.47±60.71.发病14 d时病灶侧与健侧DTI指标比较,从大脑脚到延髓各个感兴趣区,脑桥中部的MD和延髓上部的MD两侧差异无统计学意义,其余病灶侧与健侧差异均有统计学意义.病灶侧的MD较健侧下降,病灶侧的FA较健侧减小,λ1较健侧降低,λ2和λ3较健侧增加.发病后14 d的DTI指标与NIHSS呈负相关(r=-0.613,P=0.015),与BI呈正相关(r=0.530,P=0.042),与MI呈正相关(r=0.543,P=0.036).结论 DTI可以检测脑梗死后第2周的脑桥锥体束WD,其表现为λ1下降、λ2和λ3升高、FA降低,尤其是后者与运动功能障碍相关.     

超早期联合微创手术治疗基底节大量出血临床研究简

共151例高血压性基底节出血患者,于发病超早期接受经额钻孔引流联合经颞小骨窗血肿清除术（联合治疗组,68例）或去骨瓣减压血肿清除术（对照组,83例）。结果显示,联合治疗组与对照组患者术后短期及中远期疗效差异无统计学意义（均P〉0．05）,但联合治疗组患者术后苏醒快,且电解质紊乱、低蛋白血症发生率低于对照组（P〈0．05）。提示采取超早期联合微创手术治疗基底节大量出血安全、有效。     

弥散张量成像在高血压脑出血中的应用研究

高血压脑出血(hypertensive intracerebral hemorrhage,HICH)是脑血管病中病死率和致残率都很高的一种疾病,在我国,发病率占全部脑卒中的21%～48%[1],在HICH患者存活者中,约有50%～75%的患者有不同程度的残疾,其中以肢体偏瘫最为常见。皮质脊髓束损伤是其致残的重要机制。所以,如何在HICH急性期准确判断皮质脊髓束受损情况,从而     

弥散张量成像定位初级运动功能区的研究

目的 探讨弥散张量成像在定位初级运动功能区的价值.方法 20例脑深部肿瘤患者,分别进行常规MRI、fMRI及DTI检查,获取fMRI脑激活图、DTI图、3D解剖图.DTI通过三维重建皮质脊髓束定位初级运动功能区.fMRI采用手握拳激发模式,获取激活信号定位初级运动功能区.比较两种技术的吻合度,以评价DTI三维重建皮质脊髓束定位的初级运动功能区的准确性.结果 20例患者fMRI获得的激活信号主要位于对侧中央沟处,围绕着"Ω"形柄状结构分布,中央前回位于激活信号前方.所有患者均成功地完成DTI皮质脊髓束的三维重建,重建的皮质脊髓束也定位于激活信号前的脑回,两者均较好显示初级运动功能区且具有较好的一致性.结论 DTI可较好地定位初级运动功能区,这对于有肢体瘫痪患者及不能合作的儿童的初级运动功能区的定位有重要意义.     

轻度认知功能障碍与脑白质弥散张量成像的相关性研究

目的通过磁共振弥散张量成像研究不同区域脑白质损害与轻度认知功能(MCI)的关系。方法纳入2015年7月至2016年2月我院的住院患者56例为研究对象,其中MCI组34例,认知功能正常组22例。所有研究对象进行一般情况检查,完成神经心理学量表检测。通过头颅磁共振弥散张量成像(DTI)检查对不同脑区白质纤维进行部分各向异性(FA)值测量。结果 MCI组患者与认知功能正常组相比,右侧额叶FA值(0.335±0.068)、左侧颞叶白质FA值(0.391±0.032)及胼胝体膝部FA值(0.658±0.053)降低,差异具有统计学意义(P0.05)。将上述FA值和MMSE、Mo CA量表中各认知域进行典型相关分析,结果显示右侧额叶白质FA值与注意与计算力呈正相关,左侧颞叶白质和胼胝体膝部FA值与记忆力呈正相关(P0.05)。结论 MCI患者注意与计算力的障碍可能与右侧额叶白质损害有关,而左侧颞叶白质及胼胝体膝部白质的损害可能导致早期的记忆障碍。DTI可能成为超早期识别与诊断MCI的新方法。     

弥散张量成像对急性期皮质下脑梗死肢体运动功能恢复的预测

目的 对急性期内的运动功能残疾的皮质下脑梗死患者进行观察,探讨弥散张量纤维素成像(DTT)显示的锥体束累及程度等多个预测因素对运动功能改变的影响,以期发现最可靠和最密切的预测因素.方法 对82例急性脑梗死残疾患者(mRS评分≥3分),结合其基线临床特征、实验室与影像学等辅助检查及治疗方法 ,选取性别、年龄、高血压、糖尿病、高胆固醇血症、心房颤动或心绞痛史、吸烟史、酗酒史、初始残疾程度、同型半胱氨酸、C反应蛋白、治疗方式、梗死灶体积大小及锥体束累及程度作为观测指标,对患者发病后第90天的情况进行随访分析.结果 单因素差异检验采用x2检验,发现年龄(χ2=47.492,P＜0.01)、糖尿病(χ2=5.126,P=0.024)、高胆固醇血症(χ2=6.242,P=0.012)、初始残疾程度(χ2=45.359,P＜0.01)、锥体束累及程度(χ2=51.467,P＜0.01)均可影响残疾患者的康复.采用多因素Logistic回归分析对其进行多因素回归分析,结果提示年龄(OR=0.068,P=0.042)、锥体束累及程度(OR=0.026,P=0.002)是患者运动功能康复的独立预测因素,而糖尿病、高胆固醇血症、初始残疾程度无明显相关性.结论 通过DTT反映出的锥体束累及程度为对在急性期内的运动功能残疾的皮质下脑梗死患者的康复最有价值的预测因素.     

不同方法治疗高血压性基底节中等量出血的疗效对比分析简

探讨高血压性基底节中等量（20～40m1）出血患者不同治疗方法的预后与转归。共226例患者分别接受药物及支持治疗（76例）、钻孔引流术（94例）和小骨窗血肿清除术（56例）,结果显示,治愈和轻残率分别为保守治疗组23例占30．26％、钻孔引流术组50例占53．19％、小骨窗血肿清除术17例占30．36％;中残、重残和死亡为保守组53例占69．74％、钻孔引流术组44例占46．81％、小骨窗血肿清除术组39例占69．64％。提示钻孔引流术治疗高血压性基底节中等量出血患者疗效优于保守治疗和小骨窗血肿清除术,且安全可靠。     

弥散张量成像在认知功能中的研究现状

近年来磁共振弥散张量在认知功能的临床研究中正逐步地开展。它能检测出联系大脑功能分区间的纤维变化,从而反映正常人脑白质随年龄改变的情况。此外对于多发性硬化、缺血性脑白质病、阿尔茨海默病、精神分裂症患者的认知功能的研究也有一定意义。     

弥散张量成像在高血压性脑出血中的临床应用初探

目的 应用磁共振弥散张量成像技术观察基底节区高血压性脑出血皮质脊髓束的受损情况,为临床干预治疗提供可靠依据.方法 对9例基底节区HICH患者进行磁共振弥散张量成像检查,分别测量患侧皮质脊髓束受压区及健侧皮质脊髓束相应区域的FA值,并重建一名患者的FA图、方向编码彩色图、双侧皮质脊髓束3D纤维束图.结果 患侧皮质脊髓束的FA值均较对侧降低,两侧相比差异有显著性意义(t=4.9041,P<0.05);患侧皮质脊髓束区FA值下降百分比和NIHSS评分有明显相关性(r=0.8336,P<0.05);皮质脊髓束3D纤维束图可显示病变侧皮质脊髓束受损情况.结论 通过弥散张量成像可以了解基底节区HICH患者的皮质脊髓束的损伤情况,这有助于临床医生全面掌握病情,开展干预性治疗.     

高血压脑出血患者偏瘫相关弥散张量成像研究

目的利用磁共振弥散张量成像(DTI)技术研究脑出血患者偏瘫肢体功能障碍情况。方法运用DTI技术检测32例脑出血患者发病3周左右病变侧皮质脊髓束(CST)受损情况,分析其与患肢Brunnstrom评分及NIHSS评分之间的关系。结果 DTI所显示的CST受损程度与Brunnstrom评分呈负相关(P0.001),与NIHSS评分呈正相关(P0.001)。结论 DTI可直观显示与脑出血患者肢体运动功能障碍密切相关的CST受损情况,有助于病情的客观评估。     

弥散张量纤维示踪技术显示锥体束及其变异的可行性研究

目的探讨应用弥散张量成像和纤维示踪技术显示变异锥体束的可行性。方法对62例神经外科病人和4名正常人应用1.5TMRI设备进行弥散张量成像,选用延髓、中脑、内囊后支和中央前回手结四个兴趣区中的两个进行联合纤维示踪。结果示踪锥体束符合解剖学特征,47例病人和4名正常人示踪到变异的锥体束,另有3例病人存在显著的锥体束走行方式异常。结论弥散张量成像和纤维示踪技术可以在宏观上显示锥体束及其变异;有必要选用延髓全部横断面和中脑全部横断面或内囊后支作为兴趣区进行联合示踪,以防遗漏变异的锥体束。     

持续颅内压监测在高血压性脑出血中的应用

目的探讨持续颅内压监测在高血压性脑出血治疗中的临床意义。方法回顾性分析120例高血压性脑出血手术病人的临床资料,均采用脑室内颅内压监测,予以阶梯式降颅内压治疗。结果颅内压监测3~14 d,平均5.2 d。无探头置入引起的颅内大出血。术后发生感染3例,对症治疗后好转。伤后6个月,根据GOS评分:良好(包括良好和轻残)65例,占54.17%;恢复不良(包括重残和植物状态)25例,占20.83%;死亡30例,占25.00%。结论在高血压性脑出血病人手术后,行持续颅内压监测可指导降低颅内压措施的实施,早期发现病情变化,减少并发症,改善预后。     

Verifying the hypothesis of disconnection syndrome in patients with conduction aphasia using diffusion tensor imaging

BACKGROUND: It is thought in disconnection theory that connection of anterior and posterior language function areas, i.e. the lesion of arcuate fasciculus causes conduction aphasia. OBJECTIVE: To verify the theory of disconnection elicited by repetition disorder in patients with conduction aphasia by comparing the characteristics of diffusion tensor imaging between healthy persons and patients with conduction aphasia. DESIGN: Case-control observation. SETTING: Department of Neurology, Hongqi Hospital Affiliated to Mudanjiang Medical College. PARTICIPANTS: Five male patients with cerebral infarction-involved arcuate fasciculus conduction aphasia, averaged （43±2）years, who hospitalized in the Department of Neurology, Hongqi Hospital Affiliated to Mudanjiang Medical College from February 2004 to February 2005 were involved in this experiment. The involved patients were all confirmed as cerebral infarction by skull CT and MRI, and met the diagnosis criteria revised in 1995 4th Cerebrovascular Conference. They were examined by the method of Aphasia Battery of Chinese (ABC) edited by Surong Gao. The results were poorer than auditory comprehension disproportionately, and consistented with the mode of conduction aphasia. Another 5 male healthy persons, averaged （43±1）years, who were physicians receiving further training in the Department of Neurology, Beijing Tiantan Hospital were also involved in this experiment. Informed consents of detected items were obtained from all the subjects. METHODS: All the subjects were performed handedness assessment with assessment criteria of handedness formulated by Department of Neurology, First Hospital Affiliated to Beijing Medical University. Arcuate fasciculus of involved patients and health controls were analyzed with diffusion tensor imaging (DTI) and divided into 3 parts (anterior, middle and posterior segments) for determining FA value (mean value was obtained after three times of measurements), and a comparison of FA value was made between two sides. MAIN OUTCOME MEASURES: Analysis results of arcuate fasciculus DTI of healthy controls and patients with conduction aphasia. RESULTS: Five patients with conduction aphasia and 5 healthy controls participated in the final analysis. ①All the subjects were right-handedness. ② The left FA value of anterior, middle and posterior segments of arcuate fasciculus was larger than the right one in most normal volunteers, i.e. arcuate fasciculus with normal function on the left side was more than that on the right side. Because the amount of healthy controls was small, so positive conclusion has not been obtained, and only above-mentioned tendency was demonstrated. Healthy controls had good bilateral arcuate fasciculus; Three patients with conduction aphasia presented left FA value of anterior segment of arcuate fasciculus smaller than the right one, and two patients presented the left FA value larger than the right one. Four patients presented the left FA value of middle segment of arcuate fasciculus smaller than the right one, and one patient presented the left FA value larger than the right one, i.e. middle segment of arcuate fasciculus of 5 patients with conduction aphasia was all involved in at different degrees. Four patients with conduction aphasia presented the left FA value of posterior segment of arcuate fasciculus smaller than the right one, and one patient presented the left FA value larger than the right one, i.e. posterior segment of arcuate fasciculus of 5 patients was all injured at different degrees. CONCLUSION: Arcuate fasciculus of patients with conduction aphasia all is involved in at different degrees, which verifies the theory of disconnection of repetition disorder in patients with conduction aphasia.     

弥散张量成像在高血压性脑出血后皮质脊髓束损伤中的应用研究

目的：应用弥散张量纤维束成像（DTI）观察高血压性脑出血（HICH）皮质脊髓束（CST）的损伤,探讨DTI在HICH预后评估的临床应用价值。方法对16例HICH患者（壳核8例,丘脑7例,混合型1例）患者分别于入院时（7 d内）和发病后3个月进行DTI 检查,以及肌力测定和美国国立卫生研究院卒中量表（NIHSS）评分。用平均部分各向异性（FA）和表观弥散系数（ADC）测量血肿层面周围的双侧CST,测定血肿面（患侧）／对侧面（健侧）的FA值和ADC值比率。结果 HICH患者中发病后3个月肌力较好组（肌力4～-5级）的FA值比率与肌力较差组（肌力0～3级）比较,差异有统计学意义。而ADC比值在入院时及发病后3个月都没有差别。所有FA值比率＞0．8患者的运动功能都有改善和预后好。然而有1例患者虽然FA值比率不是很高,但运动功能的预后也很好,其ADC值明显升高。 CST完整的患者入院时和发病后3个月的肌力和NIHSS评分均比CST中断的患者好,发病后3个月是恢复最快的阶段。结论通过DTI的FA值比率可以了解基底核区HICH患者CST的损伤情况,有助于早期预测神经功能的恢复情况和指导治疗方案的制定。     

磁共振扩散张量成像在鉴别胶质瘤不同成分中的应用

目的 评价扩散张量成像(DTI)在区分胶质瘤不同成分方面的价值.方法 对经手术证实的30例颅内胶质瘤行MRI常规序列及DTI扫描,其中低级别胶质瘤16例,高级别14例.并根据扫描结果,计算胶质瘤强化区、非强化区、囊变坏死区、瘤周异常区及对侧正常区的DTI各向异性分数(FA值)和相对各向异性(RA值).结果 低级别胶质瘤中,未强化区与对侧正常区之间的FA值及RA值均有显著性差异(P＜0.05);高级别胶质瘤中,FA值和RA值由高到低的顺序均为:对侧正常区、瘤周异常区、强化区、囊变坏死区;且任2个区域的FA值及RA值差异均有统计学意义(P＜0.05).结论 DTI可为鉴别胶质瘤不同成分提供一定信息,对制定手术计划和放疗方案具有一定的指导作用.     

Intraoperative diffusion tensor imaging predicts the recovery of motor dysfunction after insular lesions

Insular lesions remain surgically challenging because of the need to balance aggressive resection and functional protection. Motor function deficits due to corticospinal tract injury are a common complication of surgery for lesions adjacent to the internal capsule and it is therefore essential to evaluate the corticospinal tract adjacent to the lesion. We used diffusion tensor imaging to evaluate the corticospinal tract in 89 patients with insular lobe lesions who underwent surgery in Chinese PLA General Hospital from February 2009 to May 2011. Postoperative motor function evaluation revealed that 57 patients had no changes in motor function, and 32 patients suffered motor dysfunction or aggravated motor dysfunction. Of the affected patients, 20 recovered motor function during the 6-12-month follow-up, and an additional 12 patients did not recover over more than 12 months of follow-up. Following reconstruction of the corticospinal tract, fractional anisotropy comparison demonstrated that preoperative, intraoperative and follow-up normalized fractional anisotropy in the stable group was higher than in the transient deficits group or the long-term deficits group. Compared with the transient deficits group, intraoperative normalized fractional anisotropy significantly decreased in the long-term deficits group. We conclude that intraoperative fractional anisotropy values of the corticospinal tracts can be used as a prognostic indicator of motor function outcome.     

弥散张量成像在继发全面性发作癫痫患者中的应用研究

目的 评价弥散张量成像(DTI)对于常规MRI未发现病灶的部分性继发全面性发作癫痫患者的病灶检出能力.方法 使用Siemens 3.0T磁共振成像系统对30例成年继发全面性发作癫痫患者和30例正常对照者进行扫描,得到弥散加权成像,采用基于体素的分析方法对癫痫患者和正常对照组的数据进行分析.结果 癫痫组右侧梭状回和楔前叶、右侧额内侧回和钩回、左侧扣带回、左侧颞下回、左侧小脑扁桃体和左侧中央前回的脑区FA值较正常对照组降低,差异有统计学意义(P＜0.001);癫痫组右侧海马旁回、右侧颞下回、右侧胼胝体、右侧额内侧回、右侧额下回、扣带回、右侧前扣带回、右侧舌回、右侧梭状回和枕中回,左侧颞中回、左侧钩回和左侧中央前回的脑区ADC值较正常对照组升高,差异具有统计学意义(P＜0.001);左侧直回的脑区ADC值较正常对照组降低,差异具有统计学意义(P＜0.001).结论 DTI检查可发现常规MRI检查为阴性的部分性继发全面性发作癫痫患者存在的广泛脑白质微结构异常.     

脑微出血与老年高血压性脑出血血肿扩大的相关性研究

目的探讨脑微出血对老年高血压性脑出血血肿扩大的预测作用。方法采用磁敏感加权成像对98例老年高血压性脑出血患者进行脑微出血灶观察,据发病后24 h头部CT血肿扩大和实验室指标变化,采用多因素Logistic回归分析评价脑微出血对脑出血后血肿扩大的预测价值。结果 98例患者中25例于发病后24 h复查CT显示血肿扩大,发生率约为25.51%,脑微出血组为43.75%(14/32),高于非脑微出血组的16.67%(11/66;χ2=8.319,P=0.004)。多因素Logistic回归分析显示,脑微出血为老年高血压性脑出血血肿扩大的独立影响因素(OR=0.241,95%CI:0.065~0.861;P=0.017)。结论老年高血压性脑出血急性期(24 h)合并脑微出血患者血肿扩大风险明显增加,应及时采取相关预防措施以改善预后。     

Perfusion and diffusion magnetic resonance imaging in idiopathic intracranial hypertension

OBJECTIVES: Idiopathic intracranial hypertension (IIH) is characterized by abnormal elevation of intracranial pressure without any underlying etiologic factor. Papilledema is the major clinical finding whereas neuroradiological imaging findings are almost always normal. The aim of this preliminary study was to determine if diffusion and perfusion magnetic resonance imaging in patients with IIH might be beneficial in the management of the disease. MATERIALS AND METHODS: Prospectively, we evaluated standard magnetic resonance, magnetic resonance angiographies and venographies, diffusion and perfusion magnetic resonance findings of 16 patients with IIH and of 16 age-, sex-, and weight-matched normal individuals as a control group. Patients with IIH underwent a detailed neuroophthalmologic examination and lumbar puncture for evaluation of cerebrospinal fluid pressure. Magnetic resonance imaging was performed with 1.5 T equipment. RESULTS: On physical examination, all patients had characteristic papilledema, varying degrees of headache, blurred vision and tinnitus. Cerebrospinal fluid pressure was higher than 250 mm H2O in all patients. A statistically significant decrease in cerebral blood flow in six patients, whereas insignificant increase in two were detected. Cerebral blood volume values were almost similar to normal control group's values. Significant mean transit time prolongation was found in six patients as well. CONCLUSIONS: Idiopathic intracranial hypertension is a clinical syndrome which requires prompt diagnosis and a thorough evaluation. Treatment is crucial for preventing visual loss and improving associated symptoms. It is also important to detect cerebral perfusion changes, as cerebrovascular complications may be associated. Although our patient group is small for statistical evaluation, it is a preliminary study using perfusion and diffusion magnetic resonance which may contribute to IIH management.