颅脑创伤致胼胝体损伤的MRI表现及诊断价值

目的分析颅脑创伤致胼胝体损伤的MRI影像学表现及诊断价值。方法回顾性分析本院2016年2月~2020年11月诊治的103例胼胝体损伤患者一般资料,均为颅脑创伤所致,且均在本院接受MRI和CT检查。观察患者MRI和CT影像学表现,并比较MRI和CT的诊断效能,并分析不同类型胼胝体损伤的MRI参数值。结果MRI检查显示99例患者增强扫描无明显强化、边缘清楚,4例患者存在强化或边缘不清晰,其中45例非出血性损伤患者,T1WI呈现等信号或者低信号,T2WI和DWI均呈现稍高信号,同时各扫描序列中均未见出血信号,58例出血性损伤患者,各扫描序列上均呈混杂信号,且可见出血信号;MRI和CT对膝部损伤、压部损伤以及体膝部损伤检出率比较无显著差异(P>0.05),但MRI对体部损伤检出率明显高于CT(P < 0.05);MRI和CT对出血性损伤诊断准确率比较无显著差异(P>0.05),但MRI对非出血性损伤、胼胝体萎缩、软化灶以及胶质增生诊断准确率显著高于CT(P < 0.05);两组患者DWI序列显示以及脑弥漫性轴突损伤评分均无显著差异(P>0.05),但出血性损伤T2WIFLAIR、T2WI/T1WI显示明显高于非出血性损伤(P < 0.05)。结论MRI检查应用于颅脑创伤所致胼胝体损伤较CT可显示更多的病灶,可鉴别诊断出血性损伤与非出血性损伤病灶,同时可准确定位胼胝体损伤具体部位,具有较好的临床应用价值。     

MRI诊断非出血性胼胝体损伤

目的 探讨MRI对于非出血性胼胝体损伤的诊断价值.方法 对23例胼胝体损伤患者的临床及MRI资料进行回顾性分析.结果 在23例非出血性胼胝体损伤灶中,膝部损伤5例,体部损伤11例,膝部与体部同时损伤6例,压部1例.MRI表现主要为胼胝体区斑点状、小片状异常信号区;T1WI呈低信号,T2WI呈高信号,FLAIR呈高信号.结论 MRI是诊断非出血性胼胝体损伤最佳的影像学手段.     

CT和MRI诊断胼胝体损伤的对比研究

目的 探讨CT和MRI在胼胝体损伤的应用价值.方法 对41例胼胝体损伤的患者行CT和MRI检查,对比分析胼胝体损伤的CT和MRI表现.结果 胼胝体损伤的颅脑CT和MRI表现特点：①胼胝体出血性损伤23例和非出血性损伤18例,以膝部与体部多见,压部少见;② 30例合并弥漫性脑肿胀;③ 31例常合并颅脑其他部位损伤.18例胼胝体非出血性损伤中,MRI均清晰显示,常规CT仅显示2例,经过精确概率法检验,两者差异有统计学意义（P ＜ 0.05）.23例胼胝体出血性损伤,MRI均清晰显示,常规CT显示20例,经过精确概率法检验,两者差异无统计学意义（P ＞ 0.05）.6个月后随访,MRI发现胼胝体体积缩小28例、软化灶15例、胶质增生30例,CT仅发现脑软化灶8例.结论 对于胼胝体非出血性损伤病灶和随访复查,MRI较CT检查有明显优势;对于胼胝体出血性损伤病灶,MRI和CT均有较好效果.     

Cerebral hemorrhage restricted to the corpus callosum

We report a case of an 87-yr-old woman with hemorrhage restricted to the corpus callosum. After conservative treatment at an emergency hospital, she was admitted to our hospital presenting with bilateral lower limb weakness (paraparesis) and abnormal behavior in her left hand, such as pulling at dishes while eating and purposeless "floating" of the hand while walking. We believed these behaviors to represent disconnection syndrome. Six weeks after onset, her abnormal behavior while eating disappeared. The incomplete paraparesis also improved, and she regained the ability to walk, albeit with a T cane. These findings are compatible with previously reported cases. In cases of a corpus callosum lesion, careful observation from the outset is indispensable to avoid misdiagnosis.     

In vivo quantification of global connectivity in the human corpus callosum

Histological studies on nonhuman primates have shown a rich topography of homotopic (i.e., going to the same regions) or heterotopic (i.e., going to different regions) callosal projections. Unfortunately, a complete within-subject mapping of commissural projections in humans has been limited due to the inability of typical imaging methods to detect lateral projections in posterior cortical regions. Here, we set out to map callosal projection connectivity, at the single subject level (N = 6), by combining high angular resolution diffusion weighted imaging and a novel multi-stage, region-of-interest (ROI) based fiber tracking approach. With these methods we were able to obtain a consistent increase in coverage of lateral projections to posterior cortical regions. Using 70 automatically segmented ROIs in each hemisphere and permutation statistics, we characterized significant interhemispheric connectivity patterns within each subject and observed: (1) consistent projections to frontal, parietal and occipital, but not temporal, areas, (2) a greater relative proportion of homotopic than heterotopic connections, and (3) commissural projections to the basal ganglia and thalamus that are consistent with human and nonhuman primate neuroanatomical literature. These results illustrate the first full connectivity analysis of the human corpus callosum, revealing several patterns consistent with histological findings in the nonhuman primate.     

Preventing secondary brain injury.

Traumatic brain injury affects approximately 500,000 persons each year. For those patients who survive until they reach the hospital, the major goal of the health care team is to prevent secondary injuries or insults that may follow the initial event and worsen the brain injury. Factors that can cause secondary insults to the brain include hypoxia, hypercapnia, hypotension, and intracranial hypertension. Prevention of these factors begins in the pre-hospital care phase and continues into the critical care unit. Early recognition of these factors and prompt intervention can improve the neurologic outcome of the patient with severe head injury. An understanding of the causes and effects of these secondary insults is critical to the appropriate medical and nursing management of these patients.     

Demyelination increases radial diffusivity in corpus callosum of mouse brain

Myelin damage, as seen in multiple sclerosis (MS) and other demyelinating diseases, impairs axonal conduction and can also be associated with axonal degeneration. Accurate assessments of these conditions may be highly beneficial in evaluating and selecting therapeutic strategies for patient management. Recently, an analytical approach examining diffusion tensor imaging (DTI) derived parameters has been proposed to assess the extent of axonal damage, demyelination, or both. The current study uses the well-characterized cuprizone model of experimental demyelination and remyelination of corpus callosum in mouse brain to evaluate the ability of DTI parameters to detect the progression of myelin degeneration and regeneration. Our results demonstrate that the extent of increased radial diffusivity reflects the severity of demyelination in corpus callosum of mouse brain affected by cuprizone treatment. Subsequently, radial diffusivity decreases with the progression of remyelination. Furthermore, radial diffusivity changes were specific to the time course of changes in myelin integrity as distinct from axonal injury, which was detected by betaAPP immunostaining and shown to be most extensive prior to demyelination. Radial diffusivity offers a specific assessment of demyelination and remyelination, as distinct from acute axonal damage.     

磁共振弥散张量成像观察创伤性胼胝体损伤

目的 探讨磁共振弥散张量成像对胼胝体损伤的潜在诊断价值.方法 应用磁共振弥散张量成像技术对25例闭合性颅脑损伤患者及20例健康志愿者进行观察,对胼胝体膝部、压部进行定量测定FA及ADC值,测定结果与患者组GCS进行相关分析.结果 患者组胼胝体膝部及压部的FA值较对照组显著下降(P＜0.05).患者组与对照组所测胼胝体ADC值差异无统计学意义(P＞0.05).患者组胼胝体FA值与GCS呈显著相关(P＜0.05).结论 磁共振弥散张量成像技术能清晰显示并定量与临床GCS评分密切相关的胼胝体损伤,为临床诊断及治疗提供有价值的更深层次的信息.     

MRI诊断非出血性胼胝体损伤的临床价值

目的:探讨MRI对于非出血性胼胝体损伤的临床应用价值。方法:对18例非出血性胼胝体损伤患者的临床及MRI资料进行回顾性分析。结果:全部病例均进行了CT和MRI检查。18例非出血性胼胝体损伤灶中,位于压部者9例,位于体部者4例,位于体-压部者5例。CT扫描胼胝体区均未见异常密度灶。MRI上均表现为T1WI呈等或略低信号,T2WI呈高信号。病灶呈点状、斑点状、卵圆形及条带状。结论:MRI是诊断非出血性胼胝体损伤最佳的影像学手段,其对正确诊断本病具有重要的临床应用价值。     

Contribution of alcoholism to brain dysmorphology in HIV infection: effects on the ventricles and corpus callosum

Nonrigid registration and atlas-based parcellation methods were used to compare the volume of the ventricular system and the cross-sectional area of the midsagittal corpus callosum on brain MRIs from 272 subjects in four groups: patients with HIV infection, with and without alcoholism comorbidity, alcoholics, and controls. Prior to testing group differences in regional brain metrics, each measure was corrected by regression analysis for significant correlations with supratentorial cranial volume and age, observed in 121 normal control men and women, whose age spanned six decades. Disregarding HIV disease severity, we observed a graded pattern of modest enlargement of the total ventricular system (0.28 SD for uncomplicated HIV, 0.65 SD for HIV comorbid with alcoholism, and 0.72 SD for the alcoholism group). The pattern of callosal thinning showed a similar but small ( approximately 0.5 SD) graded effect. A different pattern emerged, however, when HIV severity in the context of alcoholism comorbidity was factored into the analysis. Substantially greater volume abnormalities were present in individuals with a history of an AIDS-defining event or low CD4+ T cell counts (相似文献   

胼胝体病变的影像学特征

本文对胼胝体病变的影像学特点进行综述,旨在梳理各种胼胝体病变的影像学特征,以助鉴别诊断.     

急性一氧化碳中毒后大鼠胼胝体损伤的实验研究

目的 探讨急性一氧化碳(CO)中毒后迟发性脑病(DE)大鼠胼胝体损伤情况.方法 健康雄性Wistar大鼠,分次腹腔注射CO制备迟发性脑病模型.于中毒后第1、2、3、5、7、14、20天和对照组各时间段取胼胝体,常规制备石蜡病理切片,行HE染色观察细胞形态,变色酸染色观察髓鞘变化.于中毒后第7天和对照组相应时间段每组各8只大鼠取胼胝体,透视电镜观察髓鞘变化.于中毒后第7天和对照组相应时间段每组各8只大鼠取胼胝体,蛋白印迹试验检测髓鞘碱性蛋白(MBP)的相对含量.八臂迷宫实验训练并检测大鼠认知功能.结果 光镜下观察见HE染色中毒组出现白质疏松、泡沫细胞形成,胶质细胞肿胀、反应性增生等变化,以中毒后第7天为著.变色酸染色可见中毒组因纤维脱髓鞘而出现淡染区、泡沫细胞形成,以中毒后第7天为著.透视电镜下见胼胝体髓鞘板层结构紊乱,出现松解、断裂.蛋白印迹试验显示,中毒后胼胝体MBP下降.结论 CO中毒后随着时间推移,大鼠胼胝体出现不同程度的神经脱髓鞘改变.     

Neurodevelopmental vulnerability of the corpus callosum to childhood onset localization-related epilepsy

Recent research has suggested that childhood onset of localization-related (focal) temporal lobe epilepsy is associated with a generalized adverse effect on cognition and brain structure, especially cerebral white matter volume. This study examined the neurodevelopmental impact of childhood onset epilepsy on corpus callosum volume and the cognitive consequences of reduced cerebral connectivity. Healthy controls (n = 15) and patients with temporal lobe epilepsy (n = 32) were matched on gender and handedness, and childhood and adult onset epilepsy groups were matched on duration of epilepsy (mean = 19 years) but varied in neurodevelopmental age at onset of recurrent seizures. Results showed that childhood onset of temporal lobe epilepsy was associated with significant volumetric reduction of the corpus callosum compared to both late onset and healthy controls, with the latter two groups not differing from one another. The volumetric loss was most evident in posterior followed by anterior corpus callosum. Volumetric reduction of the corpus callosum in temporal lobe epilepsy was of clinical significance with smaller volumes associated with poorer performance on measures of nonverbal problem solving, immediate memory, speeded complex psychomotor ability and fine motor dexterity. These findings indicate that childhood onset of temporal lobe epilepsy is associated with an adverse neurodevelopmental impact on brain connectivity which is of clinical consequence and theoretical interest.     

Prenatal diagnosis of agenesis of the corpus callosum

The prenatal sonographic findings in seven cases of agenesis of the corpus callosum (AGCC) are reported. Findings that suggest AGCC on standard transverse views of the fetal cranium are emphasized. All seven cases demonstrated ventricular abnormalities including four fetuses (57%) who demonstrated laterally displaced lateral ventricles and/or disproportionate enlargement of the occipital horns. Two additional fetuses demonstrated a large midline fluid collection, representing a dilated third ventricle. The remaining case demonstrated atypical findings of a septated periventricular cystic mass. Following birth, additional malformations were found in 5 of the 7 fetuses (71%), including one fetus with trisomy 8. We conclude that AGCC can be suggested on the basis of prenatal sonographic findings and that awareness of typical findings should permit more frequent detection of this anomaly in utero. Due to the frequency of concurrent anomalies, identification of AGCC should initiate a careful search for additional malformations.     

The relationships between extent and microstructural properties of the midsagittal corpus callosum in human brain

Recent quantitative analyses of the corpus callosum (CC) have tried to assess the interhemispheric connectivity. Based on histological results showing an expansion of callosal extent at the midsagittal plane, without fiber density alterations, callosal extent was interpreted as an index of interhemispheric connectivity. The microstructural properties of the CC have also been investigated extensively using diffusion tensor imaging, to assess interhemispheric connectivity. The relationships between axonal density and callosal extent need to be investigated to understand how these parameters reflect interhemispheric connectivity. We used a semi-automated CC segmentation scheme in T1-weighted magnetic resonance image and fractional anisotropy (FA) image, respectively. The parameterization method of the segmented CC was applied to 47 right-handed healthy adult subjects. The callosal extent and microstructural properties were measured using the callosal thickness and diffusion indices (FA, mean diffusivity, and axial and radial diffusivity), respectively. Our results revealed a correlation between callosal thickness and FA on the posterior body and isthmus of the CC, which suggests that these regions are more sensitive to fiber alterations than other regions. Based on this result, we suggest that both the extent of the CC and its microstructural properties should be considered together in the estimation of interhemispheric connectivity in healthy adult populations.