常染色体显性遗传性脑动脉病伴皮层下梗死和白质脑病患者的MR定量指标及其与临床的关系

目的 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)患者的白质高信号和脑体积进行定量分析,并探讨其与临床的关系.方法 15例通过病理检查确诊为CADASIL的患者进行常规MR扫描,统计脑半卵圆中心、内囊后肢、外囊、胼胝体和颞极白质受病变累及情况.利用计算机后处理软件计算标准化颅脑体积和白质高信号占颅脑体积的百分比,并与年龄、美国国立卫生研究院卒中量表(NIHSS)和简易精神状态检查(MMSE)量表评分进行Spearman相关性分析.结果 CADASIL患者的白质病变累及部位依次为:半卵圆中心(13/15)、颞极白质(10/15)、外囊(8/15)、内囊后肢(5/15)、胼胝体(4/15).白质高信号占颅脑体积的百分比为(5.7±1.4)%,标准化颅脑体积为(1602±58)×103mm3.年龄与标准化颅脑体积呈负相关(r=-0.555,P＜0.05);白质高信号百分比与NIHSS、MMSE量表评分分别呈正、负相关(r=0.522,P＜0.05;r=-0.679,P＜0.01);标准化颅脑体积与NIHSS评分呈负相关(r=-0.624,P＜0.05).结论 CADASIL患者的白质高信号和脑体积可以定量测量,这两种影像学指标可以在一定程度上反映患者的病情.白质高信号的发展可能预示患者认知功能的下降.     

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.     

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。     

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.     

Frequency of subclinical lacunar infarcts in ischemic leukoaraiosis and cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy

BACKGROUND AND PURPOSE: Small vessel cerebrovascular disease is an important cause of vascular cognitive impairment. It is usually sporadic but also occurs secondary to the genetic disorder cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL). Recurrent lacunar stroke is a characteristic feature, although symptomatic events are relatively rare, making large numbers necessary for evaluation of potential therapies. Diffusion-weighted imaging is sensitive to acute ischemic lesions and differentiates them from chronic infarcts. Detection of asymptomatic lacunar infarcts with diffusion-weighted imaging is a potential surrogate marker for treatment trials. In this study, the frequency of asymptomatic new lesions in ischemic leukoaraiosis and CADASIL was determined as a step toward assessing the potential of this technique as a surrogate marker of disease activity. METHODS: Fifty patients with sporadic small vessel disease and 19 patients with CADASIL underwent diffusion-weighted imaging. All had been asymptomatic for 3 months before imaging. Diffusion-weighted images were screened by two raters for new lesions; lesions were confirmed as recent by a visible reduction of diffusivity on the corresponding apparent diffusion coefficient maps. RESULTS: Recent ischemic lesions were identified in four patients with sporadic small vessel disease (8.0%) and two patients with CADASIL (10.5%). CONCLUSION: Asymptomatic new lesions are found in cases of sporadic small vessel disease and CADASIL. The frequency of new lesions suggests that this approach has a potential role as a surrogate marker in therapeutic trials that warrants further investigation.     

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.     

Assessment of cerebral hemodynamics to acetazolamide using brain perfusion SPECT in cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is a hereditary microangiopathy caused by mutations in the Notch3 gene located on chromosome 19, leading to 4 cardinal features with aura, cerebrovascular ischemic events, mood disturbances, and dementia. Acetazolamide (ACZ) has been promoted as a drug to determine cerebral hemodynamics, including cerebral blood flow (CBF) and cerebrovascular reactivity (CVR) in patients with cerebrovascular disease. In CADASIL patients with small-vessel disease, ACZ may be possible to increase CBF. We present that reduced CBF was dramatically improved after administration of ACZ on Tc-99m ECD brain perfusion SPECT in a CADASIL patient.     

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.     

Role of subvoxel free fluid on diffusion parameters in brain tissue with cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy and its correlation with physical disability: histogram analysis of standard and fluid-attenuated MR diffusion

BACKGROUND AND PURPOSE: Subcortical signal intensity abnormalities and lacunar infarcts are the radiologic hallmark of cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy. MR diffusion studies reveal abnormalities in lesions and also within normal appearing white matter. To further characterize the underlying pathologic abnormality, we evaluated the role of subvoxel free fluid in brain with cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy on diffusion parameters and physical disability and analyzed the interrelation between diffusion variables and nonlacunar T2 lesion load. METHODS: Mean diffusivity maps from fluid-attenuated and standard diffusion images of 13 patients with cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy and seven age-matched control participants were compared by means of histogram analysis for three tissue compartments (whole brain parenchyma, normal appearing brain tissue, and nonlacunar lesions) by using a semiautomated region growing algorithm to define whole brain parenchyma and lesions on fluid-attenuated images. RESULTS: In both patients and control participants, the average mean diffusivity of whole brain parenchyma was lower on fluid-attenuated than on standard images (P <.001). Average mean diffusivity and peak location for all compartments were significantly elevated in patients (P <.001) and higher for lesions than for normal appearing brain tissue on both types of images (P <.001). The difference between standard and fluid-attenuated average mean diffusivity of normal appearing brain tissue, reflecting the subvoxel free fluid content, was elevated in patients (P <.05) and correlated closely with the Rankin score (Spearman's rank correlation coefficient = 0.889, P <.001). Average mean diffusivity of whole brain parenchyma and normal appearing brain tissue correlated strongly with the nonlacunar T2 lesion load (Pearson's correlation coefficient = 0.743-0.928, P <.005). CONCLUSION: This study shows that standard diffusion measurements are contaminated by free fluid partial volume effects for patients with cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy and for control participants. It also provides evidence of a clinical significance of increased subvoxel free fluid in normal appearing brain with cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy, which may be more important than either global atrophy, increased diffusivity or, T2 lesion load.     

Assessment of paramedian thalamic infarcts: MR imaging,clinical features and prognosis

Considering the highly variable vascular supply of the thalamic nuclei, MRI and clinical syndromes can be heterogeneous in ischemic diseases. We attempt to determine MRI pattern and to analyse neurological features and prognosis of paramedian infarcts. In a prospective case series within 5 years from 1999 to 2003, MRI, MRA and clinical symptoms of 38 consecutive patients were analysed. The inferomedial (posterior thalamoperforating artery) territory was affected in 89%, and lesions in the anterolateral (tuberothalamic artery) territory occurred in 42%. However, definite attribution to anterolateral or inferomedial territories was not possible in 13%. Neurological manifestations were somnolence (87%), hemisyndromes (79%), cognitive deficits (58%), oculomotor nerve palsies (53%) and vertical gaze palsies (39%). The most common aetiologies were cardiac embolism (42%), intraarterial embolism (16%), small vessel disease (13%) and large artery arteriosclerosis (13%). Pathological MRA findings were encountered in 55%, and in 18%, lesions were only visible on diffusion-weighted imaging. Correlation of MRI pattern and neurological symptoms points out anterolateral thalamic lesions as the cause of amnestic deficits. Intracranial MRA allows a non-invasive prediction of basilar tip occlusion. Our results underline the necessity of additional diffusion-weighted imaging in detecting small thalamic and midbrain lesions.     

MR imaging of cerebral abnormalities in utero

In view of the lack of ionizing radiation, ability to image in a variety of planes, and high contrast resolution, magnetic resonance (MR) imaging may have a role in obstetrical management. Three fetuses with severe cerebral abnormalities were studied by MR in utero. The findings were correlated with ultrasound examinations and with autopsy results. Ventricular dilatation and progression of hydrocephalus were detected by MR. Although fetal motion may affect image quality, diagnostically useful images were obtained with imaging times of 2.5 min.     

MEL AS综合征的MRI和MRS表现及临床意义

目的：分析线粒体脑肌病并高乳酸血症与卒中样发作（MELAs）综合征的MRI和MRS表现,探讨MRI对该病早期诊断与鉴别诊断的临床价值。方法：回顾性分析24例经临床表现及肌肉病理活检确诊的MELAS综合征患者,24例均行常规MRI（包括T1WI平扫与增强扫描,T2WI,T2FLAIR）,14例行MRA,3例行DwI,3例行MRS。综合分析所有病例的多模态MRI特征。结果：24例（79个病灶）均出现大脑皮质或皮质下片状长T1长T2信号,以枕叶（29个）、颞叶（25个）和项叶（16个）受累为主,可双侧出现;14例MRA示病变区与动脉供血区域不吻合,4例可见血管增生;10例随访患者中7例发现病灶具有游走性;3例行DWI患者均可见扩散受限所致异常信号;TzFLAIR可同时显示新、旧病灶（呈不同程度高信号）,且所显示慢性期病灶的数目与DwI相同（2例）或更多（1例）。3例MRs均可见乳酸（Lac）峰增高,且不局限于MRI所显示的病灶内,1例较陈旧病灶可见氮一乙酰天门冬氨酸（NAA）峰降低。结论：MELAS综合征具有较特异的MRI表现;MRS提示病灶内和病灶外Lac峰增高,结合高乳酸血症,对该病早期确诊有重要价值。     

Comparison of patient age with MR imaging features of gangliogliomas

OBJECTIVE: The purpose of this study was to compare MR imaging features of gangliogliomas in children less than 10 years old with those seen in patients at least 10 years old. MATERIALS AND METHODS: Our study population consisted of 15 female patients and 10 male patients with a mean age of 20 years. The early childhood group was composed of six children with a mean age of 5.5 years. The older group was composed of 19 patients with a mean age of 25.6 years. We assessed tumor volume, tumor location, percentage of tumor that was cystic, pattern of contrast enhancement, and degree of edema. RESULTS: The temporal lobe was the most common tumor location in both groups. Mean tumor volume in the early childhood group was 83 cm3, which was significantly larger than the mean tumor volume (9.78 cm3) for the older group (p = 0.001). Cystic tumors were more common in the early childhood group (83%) than in the older group (63%), and the average percentage of cysts in the cystic tumors was much higher in the early childhood group (67%) than in the older group (30%). Contrast enhancement was seen in five of six early childhood tumors and 13 of 16 tumors in older patients. Four of six tumors in the early childhood group and five of 19 tumors in the older patient group had associated edema. CONCLUSION: The mean tumor volume of gangliogliomas in the early childhood group was significantly larger than that of the older patient group. This finding may be indicative of differences in tumor growth patterns in the two groups, ability of the hemicranium to adjust to mass effect in childhood, or sampling error as a result of a relatively small sample size.     

MR characteristics and neuropathology in adult-onset autosomal dominant leukodystrophy with autonomic symptoms

BACKGROUND AND PURPOSE: Three families with adult-onset autosomal dominant leukodystrophy (ADLD) presenting autonomic dysfunction as the first symptom are reported. We describe detailed MR appearances of the brain in 2 new families and neuropathology in 2 patients and compare the findings with those in other adult-onset leukodystrophies. METHODS: Twenty subjects (12 women and 8 men; age range, 29-70 years) from 2 unrelated families with ADLD were examined with MR. Six subjects were asymptomatic. Fourteen had autonomic dysfunction. Eleven of them also had pyramidal signs and ataxia. The brains of 2 autopsied patients were examined histopathologically. RESULTS: Two subjects manifested no neurologic symptoms, signs, or MR pathology. Eighteen subjects displayed radiologic abnormalities ranging from subtle T2 high-signal-intensity changes in the upper corticospinal tract to extensive confluent white matter changes, predominantly in a frontoparietal distribution, along the corticospinal tracts down to the medulla oblongata and in the upper and middle cerebellar peduncles. Periventricular white matter was spared or less affected than the adjacent white matter. Histopathology revealed marked loss of cerebral and cerebellar myelin without signs of inflammation. Oligodendrocytes were relatively spared, the number of axons not markedly decreased, and reactive gliosis was modest. The number of Purkinje cells in the cerebellum was reduced. CONCLUSIONS: Two families with adult-onset ADLD with the disease entity originally reported by Eldridge et al. (N Engl J Med 1984;311:948-53) were described. We propose naming the disease "adult-onset ADLD with autonomic symptoms." The characteristic radiologic findings, combined with the clinical symptoms and mode of inheritance, enable the diagnosis.     

MR imaging features of primary sclerosing cholangitis: patterns of cirrhosis in relationship to clinical severity of disease

PURPOSE: To evaluate the spectrum of magnetic resonance (MR) imaging appearances of the liver in primary sclerosing cholangitis (PSC) and to examine their correlation with clinical stage of disease. MATERIALS AND METHODS: Fifty-two patients (25 female, 27 male; mean age, 43 years; age range, 11-87 years) with PSC underwent nonenhanced and gadolinium-enhanced MR imaging. Two abdominal radiologists retrospectively reviewed all images (independently and then in consensus) for the imaging pattern of the liver parenchyma, presence and grade of intrahepatic biliary ductal dilatation, and presence of areas of parenchymal atrophy or abnormal signal intensity and/or gadolinium enhancement. Imaging findings were correlated with Child class, Child-Turcotte-Pugh score, and Mayo end-stage liver disease (MELD) score. Statistical analyses (kappa scoring for interobserver agreement, McNemar test, Mann-Whitney U test, multiple regression analysis, Spearman correlation) were performed. RESULTS: Of 52 patients, seven (13%) had no imaging findings of cirrhosis, 17 (33%) had a diffuse pattern of cirrhosis, and 28 (54%) had a large macronodular pattern (with nodules >or=3 cm) (kappa = 0.84). Intrahepatic biliary ductal dilatation was observed in 44 (85%) patients and was general in 18 (35%) and segmental in 26 (50%). Peripheral wedge-shaped areas of parenchyma were observed with atrophy in 23 (44%) and 25 (48%) patients by the two readers (kappa = 0.76) and without atrophy in 18 (35%) patients by both readers (kappa = 1.00). No correlation was found between imaging findings and clinical scores (P >.05, multiple regression analysis; P =.25-.75, Mann-Whitney U test; Spearman correlation coefficients between -0.33 and 0.33). CONCLUSION: The spectrum of MR imaging appearances of PSC is diverse and comprises distinct patterns that do not appear to correlate with severity of disease. Large regenerative nodules are a frequent finding and may help to establish the diagnosis.     

Vacuolating megalencephalic leukoencephalopathy with mild clinical course validated by diffusion tensor imaging and MR spectroscopy

We report a case of presumed vacuolating megalencephalic leukoencephalopathy (VML) in a 5-year-old boy that was diagnosed when the patient was 34 months old. The patient presented clinically with megalencephaly and delayed onset of slowly progressive neurologic dysfunction. Serial MR imaging and biochemical analysis were performed to differentiate VML from other disease entities with megalencephaly and leukoencephalopathy of infantile onset. Information obtained with diffusion tensor MR imaging revealed nearly intact white matter anisotropy and vectors in parietal and posterior temporal lobes in which hyperintense abnormality was shown on conventional T2-weighted images, and proton MR spectra showed a significant decrease in n-acetylaspartate-creatine + phosphocreatine ratio.     

Patellar tracking abnormalities: clinical experience with kinematic MR imaging in 130 patients

A kinematic magnetic resonance (MR) imaging technique for assessment of malalignment of the patella, involving the acquisition of multiple sequential axial images of the patellofemoral joint during the early increments of passive knee flexion, was used to evaluate 130 patients (235 symptomatic patellofemoral joints) showing clinical evidence of having patellar tracking abnormalities. Twenty-three of the patellofemoral joints had undergone previous surgical procedures for patellar realignment. In addition, 14 (28 patellofemoral joints) asymptomatic control subjects were studied. Normal patellar tracking was observed in all of the asymptomatic subjects and in 43 (17%) of the 260 patellofemoral joints in the patient population, 18 (7%) of which were symptomatic. Sixty-nine (26%) of the patellofemoral joints had lateral subluxation of the patella, 106 (41%) had medial subluxation of the patella, 21 (8%) had excessive lateral pressure syndrome, 19 (7%) had lateral-to-medial subluxation of the patella, and two (1%) had dislocation of the patella. Of the 235 patellofemoral joints with suspected abnormalities, 217 (93%) had patellar malalignment. Of the 23 patellofemoral joints that had undergone prior surgery, 20 (87%) had abnormal patellar tracking. Thirteen of 14 (93%) patellofemoral joints that had undergone a prior arthroscopic lateral retinacular release had a medially displaced patella.