The spatial distribution of MR imaging abnormalities in cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy and their relationship to age and clinical features

BACKGROUND AND PURPOSE: Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is a condition causing recurrent subcortical strokes. MR imaging, which shows focal lacunar infarcts and leukoaraiosis, plays a central role in the diagnosis and evaluation. We studied MR imaging abnormalities in a large prospectively recruited cohort of CADASIL patients to describe the spatial distribution of abnormalities, determine how this distribution alters with age, and identify any correlations with the clinical features of the disease. METHODS: In this study, 112 CADASIL subjects from 64 families were prospectively recruited. MR imaging scans were graded by a single neuroradiologist, by using the modified Scheltens scale, to quantify the severity of high-signal-intensity changes in different brain regions. RESULTS: Lesion load increased progressively with age. Scores were maximal in the frontal, parietal, and anterior temporal cortex, and the external capsule; intermediate in the pons; and relatively low in the corpus callosum, caudate, globus pallidus, cerebellum, midbrain, and medulla. Anterior temporal pole involvement was common at all ages and, when present, usually confluent, but this was absent in 33% of patients 20-29 years of age. A history of stroke correlated with total Scheltens score and internal capsule and pontine scores. Dementia correlated with total Scheltens score and subcortical white matter score, whereas depression correlated with subcortical white matter score but not total Scheltens score. CONCLUSIONS: There is a characteristic pattern of MR imaging abnormalities in CADASIL that aids in differential diagnosis; however, some characteristic features, such as anterior temporal pole involvement, can be absent. MR imaging lesion load correlated with some clinical features including stroke and dementia, whereas depression is more common in individuals with deep white matter changes.     

2个CADASIL患者的弥散张量成像与20例正常人的比较

目的　分析2例CADASIL患者的MR特点及弥散张量指标的变化。方法　收集2例通过病理和基因检查确诊为CA DASIL的先证者的临床资料,对其进行常规MR扫描和弥散张量成像,将弥散张量成像的指标与20例正常志愿者的指标进行比较。结果　2例CADASIL患者的MR主要表现为双侧额顶叶白质内多发腔梗、脱髓鞘改变和双侧颞叶前部白质脱髓鞘。1例患者双侧外囊、内囊后肢、胼胝体膝部和压部的部分各向异性(FA)值均小于正常组的平均值减去2倍标准差,另1例患者左侧外囊的FA值小于对照组的平均值减去2倍标准差。结论　常规MR表现和弥散张量成像指标的测量均反映了CADASIL患者中存在严重的白质病变。     

Subcortical lacunar lesions: an MR imaging finding in patients with cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy

PURPOSE: To assess the prevalence and distribution of subcortical lacunar lesions (SLLs) in patients with cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL), to determine whether SLLs are an abnormal finding by studying their prevalence in healthy subjects, and to assess whether SLLs occur in other conditions associated with small vessel disease and white matter areas of high signal intensity (WMH). MATERIALS AND METHODS: The presence of SLLs, their location, and their relation to other abnormalities were assessed on magnetic resonance (MR) images (T1-weighted, T2-weighted, and fluid-attenuated inversion-recovery) obtained in 34 CADASIL patients and 20 healthy family members. Three additional control groups of healthy volunteers, elderly patients with vascular risk factors, and patients with another hereditary small vessel disease were also screened for the presence and location of SLLs. Sensitivity and specificity of the presence of SLLs for the diagnosis of CADASIL were assessed. RESULTS: SLLs were found in 20 (59%) of CADASIL patients. Incidence of SLLs increased with age (20%, <30 years; 50%, 30-50 years; 80%, >50 years). SLLs invariably occurred in the anterior temporal lobes and in areas where diffuse WMH expanded into arcuate fibers. From the anterior temporal lobe, the lesions could extend dorsally into the temporal lobes and rostrally into the frontal lobes. Lesions were not found in the parietal and occipital lobes. None of the control subjects had SLLs. Specificity and sensitivity of SLLs for CADASIL were 100% and 59%, respectively. CONCLUSION: SLLs are an abnormal finding at MR imaging that frequently occur in CADASIL patients.     

常染色体显性遗传性脑动脉病伴皮层下梗死和白质脑病的颅脑MRI表现

目的 提高对常染色体显性遗传性脑动脉病伴皮层下梗死和白质脑病(CADASIL)的颅脑MRI表现的认识.方法 对一家系2代5例患者进行头颅常规MR和MR血管成像(MRA)检查.对经Notch3基因检查或皮肤组织活检超微病理检查确诊的3例和经MRI与临床诊断的1例CADASIL的MRI资料进行分析.结果 MR检查的5例中4例CADASIL均获得明确诊断,1例排除诊断.4例CADASIL均见两侧颞叶、额叶和顶叶大致对称性皮层下与侧脑室旁白质病灶,呈长T1、长T2信号,但枕叶累及甚少且皮层不受累;O'Sullivan征阳性4例,皮层下腔隙性损害(SLLs)征阳性2例;3例半卵圆中心可见多发圆形或卵圆形囊性梗死即"黑洞",4例均见多发圆点状血管周间隙即"胡椒罐盖"样征象;4例全部显示胼胝体单发或多发斑片状显著长T1、长T2信号,其中2例伴萎缩;内囊前肢与外囊均受累,呈"人"字征;基底节和脑干可见单发或多发陈旧性腔隙性梗死灶;1例伴右侧小脑小片状梗死灶;4例全部有轻度至中度的脑干、小脑和大脑萎缩;MRA颅内Ⅰ-Ⅲ级较大动脉均未见明显异常.结论 CADASIL的颅脑MRI表现具有一定的特征性,可为CADASIL的初诊和筛选提供重要依据.     

Distribution of cranial MRI abnormalities in patients with symptomatic and subclinical CADASIL

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is a rare, inherited cause of early stroke and dementia, with a poor prognosis. This study was performed to clarify lesion appearance and pattern of lesion distribution in CADASIL. 20 members of a single family were tested for the CADASIL gene mutation and studied with cranial MRI. Scans were evaluated for lesion load and pattern of lesion distribution. 19 patients had cranial MRI, of whom 11 had normal MRI scans, were clinically unaffected and tested negative for the CADASIL gene mutation. The remaining eight patients had abnormal cranial MRI scans: seven patients were positive for the CADASIL gene mutation and one (untested) patient was severely clinically affected. Three of the patients who tested positive for the CADASIL gene mutation were clinically unaffected at the time of imaging. All eight patients with abnormal cranial MRI had subcortical white matter abnormalities, mostly in frontal and temporal lobes. Lesions involving the corpus callosum were present on sagittal T2 weighted images in four of five clinically affected and one of three clinically unaffected patients. Lesions involving the deep grey nuclei and the brain stem were common. On T1 weighted images, lesions were either poorly defined (confluent white matter hypointensity) or well defined (cystic infarcts or enlarged perivascular spaces). Atrophy was infrequent. Familiarity with the range of cranial MRI appearances may aid diagnosis of CADASIL. Recognition of cranial imaging features in asymptomatic CADASIL patients could prompt earlier diagnosis.     

Mapping of subcortical white matter abnormality in Alzheimer's disease using diffusion-weighted magnetic resonance imaging

RATIONALE AND OBJECTIVES: White matter (WM) abnormality in Alzheimer's disease (AD) has been less well characterized than cortical damage. We studied the spatial distribution of the subcortical WM abnormality using diffusion-weighted magnetic resonance imaging (DWI). MATERIALS AND METHODS: Twenty-one AD patients and seven healthy, elderly subjects were included. DWIs were obtained using a cerebrospinal fluid (CSF)-nulled pulse sequence to reduce the partial volume contamination of CSF signal. Diffusivity in the subcortical WM voxels was mapped onto the cortical surface using original software so that the spatial distribution of subcortical WM damage, which was visualized as an area of increased diffusivity, could be viewed in a three-dimensional map. The damages in the lateral surface of the bilateral cerebral hemispheres were visually evaluated, and severities of the damages in five brain regions were compared with each other. In addition, the severity of the damage in each region was correlated with patient's mini-mental state examination (MMSE) score. RESULTS: In both hemispheres, clear sparing of the pericentral regions and predominant involvement of the parietal and temporal regions were revealed with statistical significance (P < .05, respectively). Marginal correlation (P < .05 uncorrected for multiple comparisons) was observed between the damage severity in the bilateral frontal and right temporal regions and patient's MMSE score. CONCLUSION: We demonstrated a subcortical WM abnormality over the parietal and temporal regions with clear sparing of the pericentral region using our mapping method, which supported the hypothesis that the subcortical WM abnormality in AD originates in Wallerian degeneration.     

基于体素的形态测量学在震颤麻痹型多系统萎缩中的应用

目的 评价震颤麻痹型多系统萎缩(MSA-P型)患者全脑灰、白质体积减少区域及分布特征.方法 选取13例临床拟诊为MSA-P型可能性大的患者及14名年龄匹配的正常对照者行全脑三维快速扰相梯度回波(3D fast spoiled gradient echo,3D-FSPGR)序列扫描,采用基于体素的形态测量学(voxel-based morphometry,VBM)分析方法的统计参数图软件(statistical parametric mapping,SPM)8,对MSA-P型患者及正常对照者的灰、白质体素进行分析.结果 与正常对照者相比,MSA-P患者的脑灰、白质体积均减少;脑灰质减少区多数区域呈双侧对称分布:包括双侧辅助运动区、背侧后扣带皮层、额叶内侧回、颞上回、小脑半球皮层等;少数区域仅累及单侧,如右侧初级运动皮层、体感联合皮层及左侧下前扣带皮层等.脑白质区主要累及双侧额上回、楔前叶、额叶下,左侧颞上回、扣带回及右侧额眶回、颞叶下等.结论 VBM方法具有自动、全面的特点,能客观地反映MSA-P患者组全脑结构的差异.     

伴皮质下梗死和白质脑病常染色体显性遗传性脑动脉病CT平扫特点

目的：探讨伴皮质下梗死和白质脑病的常染色体显性遗传性脑动脉病（CADASIL）CT平扫特点。方法：对8例经临床、MRI、病理学及基因检查确诊为CADASIL患者的CT平扫资料进行回顾性分析。结果：CADASIL患者脑CT平扫特点主要表现为颞极、额叶前部白质疏松,可伴有腔隙性梗死灶,随年龄增长上述病灶逐渐加重。结论：CADASIL病例CT平扫存在特征性的脑白质病变,CT对该病的筛选有重要作用。     

Cortical hypometabolism and crossed cerebellar diaschisis suggest subcortically induced disconnection in CADASIL: an 18F-FDG PET study.

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is an inherited small-vessel disease caused by mutations in the NOTCH3 gene. As in sporadic small-vessel disease, ischemic lesions are largely confined to subcortical structures, whereas the cortex is spared. CADASIL, therefore, may serve as a model to study subcortically induced remote effects. The purpose of this study was to evaluate with (18)F-FDG PET whether regional cerebral metabolic rate of glucose (rCMRglc) is altered in CADASIL patients and, if so, whether there is evidence of subcortically induced disconnection. METHODS: Eleven CADASIL patients (7 women, 4 men; mean age, 55.8 +/- 6.7 y) without cortical lesions on brain MR images underwent PET after intravenous injection of 120 MBq (18)F-FDG, with calculation of rCMRglc according to a previously published method. For further processing, patient studies were registered to a template of a healthy control group and region-of-interest-based and voxelwise comparisons were performed. RESULTS: In CADASIL patients, mean rCMRglc was significantly reduced in all cortical and subcortical structures, compared with the values in healthy volunteers. In the subcortical gray matter, metabolic rates, given as the percentage of the mean of healthy volunteers, were 49.7%, 65.3%, and 51.6% in the caudate, putamen, and thalamus, respectively. Among cortical structures, the values were 66.9%, 67.9%, 67.2%, and 76.5% for the frontal, parietal, temporal, and occipital lobes, respectively. On an individual level, most patients showed marked asymmetry and inhomogeneities of cortical glucose metabolism. In 6 (55%) CADASIL patients, there was evidence of crossed cerebellar diaschisis. CONCLUSION: This study showed that cortical glucose metabolism is significantly lower in CADASIL patients than in healthy volunteers. The observed decrease in rCMRglc may in part be explained by a reduction of cerebral blood flow and neuronal loss. In addition, our data provide evidence of remote effects secondary to the functional disruption of subcortical fiber tracts in this particular type of small-vessel disease.     

Pre- and posttreatment MR imaging findings in lead encephalopathy

A 41-year-old man suspected of having lead poisoning was evaluated with MR imaging before and after British antilewisite therapy. The MR imaging findings showed bilateral symmetric involvement of the occipital lobe, affecting predominantly the gray-white matter junction and the subcortical white matter. A right cerebellar lesion was noted, with focal hyperintensities involving the gray-white matter. Similar lesions were seen in the temporal, parietal, and frontal regions. These lesions resolved after chelation therapy.     

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy: structural MR imaging changes and apolipoprotein E genotype

BACKGROUND AND PURPOSE: Apolipoprotein E (apoE) genotype plays an important role in the development, maintenance, and response to injury of the central nervous system. It has been suggested that apoE epsilon4 genotype is a risk factor for several neurologic disorders. We investigated the correlation between the apoE genotype and radiologic data in patients with cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL). METHODS: T1-weighted, dual fast spin-echo, T2*-weighted gradient echo, and fluid-attenuated inversion recovery MR imaging scans were obtained from 36 CADASIL patients (21-59 years of age). The number of lacunar infarcts and microbleeds and the presence of subcortical lacunar lesions were determined. The amount of white matter hyperintensities was assessed by using semiautomated segmentation software. The relation between the radiologic endophenotype of CADASIL and the apoE genotype was assessed by using a Student t test for unpaired data and Fisher exact test. RESULTS: White matter hyperintensities, lacunar infarcts, microbleeds, and subcortical lacunar lesions were not found to be associated with the presence of an epsilon4 allele. CONCLUSION: The variability of structural MR imaging lesions in CADASIL is independent of apoE genotype and other processes must underlie the variable natural history of the disease.     

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy: decrease in regional cerebral blood volume in hyperintense subcortical lesions inversely correlates with disability and cognitive performance

BACKGROUND AND PURPOSE: Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is an arteriopathic syndrome related to a genetic defect on chromosome 19. Characteristic changes in CADASIL can be observed onT2-weighted MR images in the subcortical white matter. The purpose of this study was to measure changes of regional cerebral blood volume (rCBV) with dynamic contrast-enhanced MR imaging and to correlate the changes to disability and cognitive performance. METHODS: We obtained rCBV measurements of 24 individuals with proven CADASIL on a 1.5-T MR imaging unit. A susceptibility-weighted MR imaging sequence was used for bolus tracking. Principles of the indicator dilution theory were applied to estimate values of absolute rCBV (mL/100 g). Disability was determined by using the Rankin scale, and overall cognitive performance was assessed by using the Mini-Mental State Examination. RESULTS: The mean rCBV in the subcortical white matter that was hyperintense on the T2-weighted images (2.7 +/- 0.8 mL/100 g) was significantly lower than the rCBV in the white matter that appeared normal on the T2-weighted images (4.4 +/- 1.3 mL/100 g) (P <.05). The mean rCBV in the gray matter was within the normal range (8.3 +/- 1.7 mL/100 g). Both cognitive impairment and disability negatively correlated with rCBV in the subcortical white matter that was hyperintense (P <.05) but not with rCBV in the normal appearing white matter. rCBV did not correlate with age. CONCLUSION: rCBV measured in the hyperintense subcortical white matter in individuals with CADASIL was decreased and inversely correlated with disability and cognitive impairment.     

Lobar distribution of changes in gray matter and white matter in memory clinic patients: detected using magnetization transfer imaging

BACKGROUND AND PURPOSE: Previous studies have shown involvement of both gray matter (GM) and white matter (WM) in mild cognitive impairment (MCI) and Alzheimer disease (AD). In this study, we assessed the lobar distribution of the GM and WM pathology over the brain and the association of lobar distribution with global cognitive decline. MATERIALS AND METHODS: Fifty-five patients with AD, 19 patients with MCI, and 43 subjects with normal cognitive function participated in this study. GM and WM were segmented on dual fast spin-echo and fluid-attenuated inversion recovery MR images. A custom template representing anatomic areas was applied. Magnetization transfer imaging (MTI) peak height and mean magnetization transfer ratio (MTR) provided measures for structural brain damage. RESULTS: Both mean MTR and MTI peak height showed that patients with AD had more structural brain damage in the GM of all lobes compared with controls. Patients with MCI had lower GM peak height compared with controls for the temporal and frontal lobe. WM peak height was lower for all lobes investigated for patients with both AD and MCI. WM mean MTR was lower in the frontal, parietal, and temporal lobes for patients with AD compared with controls. Age and both temporal GM peak height and mean MTR were the only parameters that predicted cognition. CONCLUSION: This study shows that in addition to more focal GM MTI changes in the temporal and frontal lobes, widespread WM changes are present in the earliest stages of AD. This might point to an important role for WM pathology in the earliest stage of AD.     

Cree leukoencephalopathy: neuroimaging findings.

PURPOSE: To describe the computed tomographic (CT) and magnetic resonance (MR) imaging findings in Cree leukoencephalopathy. MATERIALS AND METHODS: The authors retrospectively reviewed the medical records and neuroimaging studies in 12 infants with Cree leukoencephalopathy (CT in 12 infants, MR in six). The diagnosis was established clinically in six patients and at autopsy in the other six. RESULTS: At CT, extensive, diffuse, and symmetric hypoattenuation was seen in the cerebral and cerebellar white matter in all 12 patients. Hypoattenuation was also seen in the corpus callosum in 11 (92%), internal capsule in 10 (83%), globus pallidus in nine (75%), brainstem in nine (75%), and thalamus in four (33%). The caudate nucleus and putamen were spared. On T2-weighted MR images in six patients, the cerebral and cerebellar white matter, including the subcortical arcuate fibers, was hyperintense as were the internal capsule, corpus callosum, corticospinal tracts, and globus pallidus. The thalamus was affected in four (67%) patients, pons in five (83%), and medulla in four (33%). The caudate nucleus and putamen were not affected. CONCLUSION: Cree leukoencephalopathy causes striking symmetric and diffuse involvement of the cerebral and cerebellar white matter and brainstem with sparing of the caudate nucleus and putamen.     

基于体素的遗忘型轻度认知障碍和轻度阿尔茨海默病全脑白质MR扩散张量成像分析

目的 采用基于体素的分析(VBA)方法研究遗忘型轻度认知障碍(aMCI)患者和轻度阿尔茨海默病(AD)患者全脑白质微观结构改变的特点及其与灰质萎缩模式的关系.方法 选取33例aMCI患者(aMCI组)、32例轻度AD患者(轻度AD组)和31名正常老年人(健康对照组),对全脑进行3.0 T DTI及三维快速扰相梯度反转回波(3DFSPGR)脉冲序列扫描.采用统计参数图(SPM)5软件对被试者的结构图像及各向异性(FA)图进行预处理,然后采用t检验对aMCI组、轻度AD组和正常对照组的全脑灰质体积及FA值进行基于体素的统计学比较,计算出有统计学意义的脑区.结果 与正常对照组比较,aMCI组的双侧额颞叶和左侧枕叶白质、左侧扣带前部、左侧顶下小叶、右侧脑室三角区外上方白质的FA值减低;轻度AD组的双侧额颞枕叶、海马旁白质、扣带前部、胼胝体、侧脑室三角区旁白质、顶下小叶、左侧颞于、左侧丘脑、右侧楔前叶FA值减低.基于体素的形态测量学(VBM),分析发现,aMCI患者组左侧海马、海马旁回、舌回、颞上回,双侧岛叶、颞中回出现了灰质萎缩;轻度AD患者组双侧海马、海马旁回、杏仁核、丘脑、额叶、颞叶、顶叶、枕叶皮质出现了灰质萎缩.aMCI与轻度AD患者组全脑白质FA值减低的模式与灰质萎缩模式不同.aMCI组与轻度AD组比较未发现具有统计学意义的FA值减低脑区.aMCI、轻度AD患者组全脑白质FA值与简易智能精神状态检查量表(MMSE)评分没有相关性.结论 基于体素的MR DTI全脑白质分析能够较全面、客观地揭示aMCI、轻度AD的脑白质损害的模式.aMCI、轻度AD患者白质损害的模式与灰质不同,提示脑白质病变是多种病理机制导致的.aMCI患者向轻度AD进展过程中,脑白质各向异性改变不显著,脑白质FA值的改变可能无法反映患者认知功能障碍的严重程度.

Abstract：

Objective To evaluate the microstructural integrity of white matter (WM) in patients with amnestic mild cognitive impairment (aMCI) and mild Alzheimer's disease (AD) using voxel-based analysis (VBA), and investigate the relationship between WM abnormalities and gray matter(GM) atrophy.Methods Thirty-three cases with aMCI, 32 cases with mild AD and 31 normal aging volunteers as control subjects were scanned on a 3.0 T MR system using diffusion tensor imaging (DTI) and three-dimensional spoiled gradient-recalled(3DSPGR) sequences. Fractional anisotropy (FA) maps and morphological images were preprocessed by SPM5 and voxel-based comparisons between the 2 patient groups and the control group were performed by t test. Results Relative to the control group, patients with aMCI showed significantly reduced FA value in bilateral frontal, temporal and left occipital WM, left anterior part of cingulum, left inferior parietal lobule, and the W M adjacent to the triangular part of the right lateral ventricle(k≥20 voxels).In mild AD,significantly reduced FA value was found in bilateral hippocampal,inferior parietal lobular,frontal,temporal,and occipital WM,bilateral corpus callosum,anterior part of cingulums,the WM adjacent to the triaangular part of the bilateral lateral ventricles,left temporal stem,left thalamus,right precuneus(k≥20 voxels).Significantly reduced GM volume was found in left hippocampus,parahippocampal gyrus,lingual gyrus and superior temporal gyrus,bilateral insulae and middle temporal gyri in aMCl group whencompared with control group(k≥50 voxels).In mild AD,significantly reduced GM volume was found in bilateral hippoeampi,parahippocampal gyri,amygdalae,thalami,temporal,parietal,frontal,occipital cortex(k≥50 voxels).The pattern of areas with reduced FA differs;from that of the GM volumetric reduction.No areas with significantlv reduced FA was detected in aMCl compared with mild AD. There was no significant correlation between FA value of WM in patient groups and Mini-Mental State Examination(MMSE)scores.Conclusions Voxel-based MRI DTI analysis of whole brain white matter can objectively reveal widespread white matter abnormalities in early-stage AD.The difierence between WM FA reduction pattern and GM volumetric reduction pattern indicates that the pathological WM changes in earlyslage AD were caused by multiple mechanisms. FA did not vary significantly in patients pr0gressing from aMCI to mild AD and can hardly reflect the severitv of cognitive function damage in these patients.     

环孢霉素A致可逆性后部白质脑病综合征的MRI表现

目的探讨环孢霉素A诱发可逆性后部白质脑病综合征(PRLS)的MRI表现。资料与方法回顾性分析1例PRLS的临床资料和MRI表现并复习文献。结果MRI显示PRLS以顶枕叶为主的皮层及皮层下白质病变,病变多呈双侧对称性分布,偶可累及双侧颞叶后部及额叶,T2WI和液体衰减翻转恢复序列(FLAIR)对病变的显示有独特的作用,扩散加权成像(DWI)能够确定PRLS的临床分期。结论PRLS在MRI上具有特征性。MRI表现结合临床资料,对PRLS多能作出正确的诊断。     

Detection of early neuronal damage in CADASIL patients by q-space MR imaging

Introduction

q-Space imaging is a novel magnetic resonance (MR) technique that enables the assessment of ultrastructural changes of white matter. We hypothesized that this technique would facilitate the assessment of the progressive nature of neuronal damage seen in cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL).

Methods

This study was approved by the institutional review board. Seven consecutive adult patients (five men and two women) with the CADASIL gene mutation were studied. Two patients were preclinical cases without overt episodes of stroke. The control group consisted of five normal volunteers. All MR examinations were performed using a 1.5-T whole-body imager. q-Space imaging was performed using a single-shot, echo-planar imaging technique and Δ/δ?=?142/17 ms. Gradient magnitudes were increased in nine steps to reach a maximal b value of 10,000 s/mm². Total acquisition time of q-space imaging was 25 min. The ADC maps calculated from the b?=?1,000 images were used for comparisons.

Results

Both q-space imaging and ADC maps depicted progressive neuronal damage. Early neuronal damage was especially well depicted using q-space imaging, with preferential involvement of the frontal lobes and central gray matters. Later progression was better depicted by b?=?1,000 ADC maps at the temporal lobes. Visual assessment of images revealed a trend for occipital lobe sparing, especially on q-space imaging.

Conclusion

q-Space imaging demonstrated early neuronal damage in a characteristic distribution. Since this method appears to be sensitive to early neuronal damage, it could conceivably aid in monitoring patients in the preclinical stage and may help in assessing the effects of future medical interventions.     

Dynamic perfusion patterns in temporal lobe epilepsy

Purpose  To investigate dynamic ictal perfusion changes during temporal lobe epilepsy (TLE). Methods  We investigated 37 patients with TLE by ictal and interictal SPECT. All ictal injections were performed within 60 s of seizure onset. Statistical parametric mapping was used to analyse brain perfusion changes and temporal relationships with injection time and seizure duration as covariates. Results  The analysis revealed significant ictal hyperperfusion in the ipsilateral temporal lobe extending to subcortical regions. Hypoperfusion was observed in large extratemporal areas. There were also significant dynamic changes in several extratemporal regions: ipsilateral orbitofrontal and bilateral superior frontal gyri and the contralateral cerebellum and ipsilateral striatum. Conclusion  The study demonstrated early dynamic perfusion changes in extratemporal regions probably involved in both propagation of epileptic activity and initiation of inhibitory mechanisms.     

Whole-brain histogram and voxel-based analyses of apparent diffusion coefficient and magnetization transfer ratio in celiac disease, epilepsy, and cerebral calcifications syndrome

BACKGROUND AND PURPOSE: Diffusion and magnetization transfer (MT) techniques have been applied to the investigation with MR of epilepsy and have revealed changes in patients with or without abnormalities on MR imaging. We hypothesized that also in the coeliac disease (CD), epilepsy and cerebral calcifications (CEC) syndrome diffusion and MT techniques could reveal brain abnormalities undetected by MR imaging and tentatively correlated to epilepsy. MATERIALS AND METHODS: Diffusion and MT weighted images were obtained in 10 patients with CEC, 8 patients with CD without epilepsy and 17 healthy volunteers. The whole brain apparent diffusion coefficient (ADC) and MT ratio (MTR) maps were analyzed with histograms and the Statistical Parametric Mapping 2 (SPM2) software. We employed the non-parametric Mann-Whitney U test to assess differences for ADC and MTR histogram metrics. Voxel by voxel comparison of the ADC and MTR maps was performed with 2 tails t-test corrected for multiple comparison. RESULTS: A significantly higher whole brain ADC value as compared to healthy controls was observed in CEC (P = 0.006) and CD (P = 0.01) patients. SPM2 showed bilateral areas of significantly decreased MTR in the parietal and temporal subcortical white matter (WM) in the CEC patients. CONCLUSION: Our study indicates that diffusion and MT techniques are also capable of revealing abnormalities undetected by MR imaging. In particular patients with CEC syndrome show an increase of the whole brain ADC histogram which is more pronounced than in patients with gluten intolerance. IN CEC patients, voxel-based analysis demonstrates a localized decrease of the MTR in the parieto-temporal subcortical WM.     

Congenital muscular dystrophy with merosin deficiency: 1H MR spectroscopy and diffusion-weighted MR imaging

PURPOSE: To prospectively use hydrogen 1 ((1)H) magnetic resonance (MR) spectroscopy and apparent diffusion coefficient (ADC) maps to try to explain the discrepancy between the extensive white matter (WM) abnormalities observed at MR imaging and the relatively mild neurocognitive decline in patients with merosin-deficient congenital muscular dystrophy (CMD). MATERIALS AND METHODS: The hospital ethics committee approved this study, and informed consent was obtained. Nine patients (five boys, four girls; age range, 3-9 years; mean, 6 years +/- 2 [standard deviation]) with merosin-deficient CMD underwent T1-weighted, T2-weighted, fluid-attenuated inversion recovery, and diffusion-weighted MR imaging and (1)H MR spectroscopy, which was performed in the parieto-occipital WM (POWM) and frontal WM (FWM) by using stimulated-echo acquisition mode. Metabolite (N-acetylaspartate [NAA], choline-containing compounds [Cho], and myo-inositol [mI]) ratios were calculated in relation to creatine/phosphocreatine (Cr) and water (H(2)O). NAA/Cho was also calculated. ADCs were calculated in approximately the same locations that were studied with spectroscopy. For comparison, (1)H MR spectroscopy (n = 10) and ADC mapping (n = 7) were also performed in 10 healthy age- and sex-matched control subjects (three boys, seven girls; age range, 4-9 years; mean, 6 years +/- 1). Statistical analysis involved the t test for comparison between different groups; correlation between ADC and spectroscopy results was studied with the Pearson test. RESULTS: MR imaging revealed evidence of bilateral WM involvement in all patients. Whereas their NAA/Cr and Cho/Cr were normal, their mI/Cr was slightly increased compared with that in control subjects (P = .03 in FWM and P = .07 in POWM), and their NAA/Cho was decreased in POWM (P = .03). NAA/H(2)O, Cr/H(2)O, Cho/H(2)O, and mI/H(2)O were considerably decreased (P < .05 for all) and ADC values were increased (P < .001) in WM in all patients versus these values in WM in control subjects. There was significant correlation between ADC values and metabolite/water ratios (r = -0.777 to -0.967, P < .05). CONCLUSION: ADC mapping and (1)H MR spectroscopy reveal abnormally high free-water concentrations in the WM of patients with merosin-deficient CMD.