Diffusion-weighted magnetic resonance imaging of neuro-Beh?et's disease]

We report 2 patients (35-year-old and 38-year-old men) with neuro-Beh?et's disease and characterize their diffusion-weighted MRI (DWI) findings of brain. T2-weighted and fluid-attenuated inversion recovery images obtained during the acute phase of neurological manifestations demonstrated multiple hyperintense lesions with a characteristic distribution in the brain including brainstem, thalamus, basal ganglia, and cerebral hemisphere. Most of these lesions did not exhibit increased signal intensity on DWI. This MRI profile, especially the combination of isointensity on DWI and hyperintensity on T2-weighted image, of neuro-Beh?et's disease is similar to that of multiple sclerosis, and different from that of acute cerebral infarction and herpes simplex encephalitis.     

A case of diffuse neurofibrillary tangles with calcification

We report a 79-year-old female with atypical senile dementia with Fahr-type calcification. The patient started to show memory disturbance at the age of 75 years, followed by visual hallucination, stereotypy, personality changes such as irritability, aggression and disinhibition. Brain computed tomography (CT) demonstrated bilateral and symmetric calcification of the basal ganglia and thalamus. Magnetic resonance imaging (MRI) revealed diffuse cortical atrophy pronounced in the fronto-temporal areas. On MRI T1-weighted images the calcified areas showed a mixture of low- and high-intensity signals. Based on the overlapping clinical symptoms of Alzheimer's disease and Pick's disease, together with the brain CT and MRI findings, we clinically diagnosed the patient as having 'diffuse neurofibrillary tangles with calcification' (DNTC). The characteristics of psychiatric symptoms and neuroradiological findings in DNTC are discussed.     

基底节生殖细胞瘤的临床和影像学分析

目的分析伴脑干萎缩的基底节生殖细胞瘤临床特点及影像学改变，以提高对此病的认识。方法结合文献分析7例基底节生殖细胞瘤患者的临床和影像学特征。结果7例患者均为年轻男性，主要表现为缓慢进展的轻偏瘫；影像学显示肿瘤主要位于基底节，MRIT。加权像上呈低或等低混杂信号，T2加权像上呈高或等高混杂信号，伴有同侧大脑半球或脑干萎缩。结论基底节生殖细胞瘤临床及影像学缺乏特异性；年轻患者出现缓慢进行性偏瘫，伴有病变同侧大脑偏侧萎缩或／和大脑脚萎缩的基底节病变应高度怀疑基底节生殖细胞瘤。     

Calcification mimicking manganese-induced increased signal intensities in T1-weighted MR images in a patient taking herbal medicine: case report

Characteristic high signal intensities confined to the globus pallidus on T1-weighted magnetic resonance image (MRI) can be observed in manganese (Mn)-exposed workers, however, these high signals should be differentiated from those due to other causes such as fat, hemoglobin breakdown products, melanoma, neurofibromatosis, and calcification. A 39-year-old woman was admitted with mutism and involuntary movements which had developed the day before. She had ingested two packs of liquid herbal medicine containing 0.53 mg of Mn daily for 4 months prior to visiting our hospital. Her MRI showed high signals, confined mainly to the globus pallidus on T1-weighted images. Follow-up brain MRI at an interval of 11 months showed no interval change. Brain computed tomography (CT) at the time of the second MRI showed symmetric calcification on both globus pallidus. Blood levels of liver function tests, calcium, phosphorus, and parathyroid hormone were within normal ranges. The increased signals, which were first presumed to be induced by Mn, were concluded to be due to calcification based on the following reasons. First, follow-up brain MRI at an interval of 11 months did not show any interval change. Second, the ingested amount of 1.06 mg Mn daily for 4 months is even less than that added to mineral supplements for adults. Third, Mn-induced high signals in T1-weighted MRI do not show any abnormal findings in brain CT. The present case report suggests that brain CT should be performed to rule out symmetric calcification on basal ganglia in patients showing increased signals in T1-weighted MRI, but who do not have a significant exposure history to Mn. The present report also showed that the amount of 1.06 mg Mn daily ingested for 4 months did not cause the high signal in brain MRI.     

Delayed ischemic hyperintensity on T1-weighted MRI in the caudoputamen and cerebral cortex of humans after spectacular shrinking deficit

BACKGROUND AND PURPOSE: Transient internal carotid artery (ICA)-middle cerebral artery (MCA) occlusion caused by cardiogenic embolus can lead to spectacular shrinking deficit (SSD): sudden hemispheric stroke syndrome followed by rapid improvement. The aim of this study was to investigate sequential neuroradiological changes in the brains of patients after SSD compared with those after brief cardiac arrest and hypoglycemia, which we previously studied with the same methods. METHODS: We serially studied CT scans and MR images obtained at 1.5 T in 4 patients with SSD. All 4 patients suffered from transient neurological deficits due to cardiogenic embolus in ICA-MCA. The symptoms began to disappear from 25 to 50 minutes after onset. RESULTS: Repeated CT scans demonstrated no abnormal findings in the affected cerebral hemisphere in 3 of the 4 patients and a small cortical infarct in the remaining 1. In each patient, repeated MRI between day 7 and month 23 after stroke showed basal ganglionic and cortical lesions. These lesions were hyperintense on T1-weighted and relatively hypointense on T2-weighted imaging. These ischemic lesions of hyperintensity on T1-weighted MRI subsided with time. CONCLUSIONS: Transient ICA-MCA occlusion leading to SSD produces a specific ischemic change with delayed onset in the basal ganglia and cerebral cortex in humans on MRI but not CT scans. We speculate that the lesions represent incomplete ischemic injury, including selective neuronal death, proliferation of glial cells, paramagnetic substance deposition, and/or lipid accumulation. Unlike brief cardiac arrest or hypoglycemia, the localized lesions on MRI of patients after SSD seem to be incomplete and to differ from infarction or hemorrhage.     

Basal ganglia calcification on computed tomography: clinical characteristics in 25 patients

Twenty-five patients presenting basal ganglia calcification were assessed. This finding comprised 0.68% of all skull CT scan carried out during the period. Two patients were neurologically asymptomatic and 23 presented a variety neurological disorders--headache (7 patients), stroke (5 patients), extrapyramidal syndromes (2 patients), tumor (2 patients), epilepsy (1 patient), mental retardation (1 patient), dementia (1 patient), cranial trauma (1 patient), other neurological conditions (3 patients)--or were asymptomatic from the neurological point of view (2 patients). Findings in the CT scan other than the basal ganglia calcification were observed in 15 (60%) patients. There was a clinical-CT scan correlation in these cases but not in those in which the basal ganglia calcification was an isolated finding. This study highlights the fact that basal ganglia calcification is often a nonspecific finding on CT scan and that it may not be possible to establish a clinical-pathological correlation between them.     

Sylvian fissure dermoid cyst with intratumoral hemorrhage: case report

It is rare for a dermoid cyst to develop intratumoral hemorrhage. A 61-year-old woman had a sudden-onset left hemiparesis and slow response to verbal requests for one week when unenhanced computed tomography scanning revealed a mixed iso- and hypo-dense heterogeneous lesion in the right fronto-temporal area. T1-weighted magnetic resonance imaging (MRI) of the brain showed a mixed hyper- and hypo-intense tumor in the right fronto-temporal area. The tumor became hyperintense on T2-weighted MRI and was faintly enhanced at tumor periphery on T1-weighted MRI. The tumor was excised and pathological examination revealed a dermoid cyst with intratumoral hemorrhage. The post-operative course was complicated by hemorrhage in the tumor bed, which was evacuated immediately. The patient improved and could walk without support two weeks after the second operation. After 1 year of follow-up, she was well and without neurological deficits. To the best of our knowledge after a literature review, only two previous cases of dermoid cyst have featured intratumoral hemorrhage.     

Sylvian fissure dermoid cyst with intratumoral hemorrhage: case report

It is rare for a dermoid cyst to develop intratumoral hemorrhage. A 61-year-old woman had a sudden-onset left hemiparesis and slow response to verbal requests for one week when unenhanced computed tomography scanning revealed a mixed iso- and hypo-dense heterogeneous lesion in the right fronto-temporal area. T1-weighted magnetic resonance imaging (MRI) of the brain showed a mixed hyper- and hypo-intense tumor in the right fronto-temporal area. The tumor became hyperintense on T2-weighted MRI and was faintly enhanced at tumor periphery on T1-weighted MRI. The tumor was excised and pathological examination revealed a dermoid cyst with intratumoral hemorrhage. The post-operative course was complicated by hemorrhage in the tumor bed, which was evacuated immediately. The patient improved and could walk without support two weeks after the second operation. After 1 year of follow-up, she was well and without neurological deficits. To the best of our knowledge after a literature review, only two previous cases of dermoid cyst have featured intratumoral hemorrhage.     

缺血性卒中患者脑微出血的相关因素分析

目的 探讨缺血性卒中患者发牛脑微出血(CMBs)的相关因素. 方法 对85例急性缺血性卒中患者进行磁共振检查,其中包括梯度回波T2加权成像(GE-T2~*WI),并对患者的临床资料和影像学特点进行分析. 结果 26例(30.6%)患者中共检出CMBs 124个,每位患者的CMBs数目在1～16个之间.CMBs在基底节丘脑区和皮质一皮质下区分布较多,在幕下区较少见.发生在脑十的CMBs可有相关症状及体征.CMBs数目与年龄、腔隙性梗死数目及白质疏松程度评分有相关性(r=0.243,P=0.025;r=337,P=0.002;r=0.438,P=0.000).CMBs在GE-T2~*WI上显影良好,部分CMBs可在自旋叫波(SE)T2WI及DWI序列上显影. 结论 CMBs是脑微小血管病变标志,主要预测因素有高龄、多发腔隙性梗塞和白质疏松.     

脑脂肪栓塞早期诊断及治疗

目的探讨脑脂肪栓塞的早期诊断及治疗。方法回顾性分析我院收治的颅脑外伤并发脑脂肪栓塞2例。结果患者MRI提示两侧大脑半球、基底节区、卵圆中心及脑干可见多发斑点斑块状等T1、长T2异常信号影,液体衰减反转成像（FLAIR）呈高信号,弥散加权成像（DWI）呈高信号。患者凝血机制也发生改变。结论通过早期的MRI结合凝血机制改变可以尽早诊断脑脂肪栓塞,使患者得到有效救治。     

Chagasic Granulomatous Encephalitis in Immunosuppressed Patients; Computed Tomography and Magnetic Resonance Imaging Findings

American trypanosomiasis (Chagas' disease), a zoonosis caused by Trypanosoma cruzi with a high incidence in Latin America, may induce an uncommon form of localized encephalitis termed “chagoma,” found in few immunocompromised patients. The computed tomography (CT) and magnetic resonance imaging (MRI) findings of brain chagoma are reported for 3 males (ages 32, 32, and 9 yr), the first 2 infected with human immunodeficiency virus (HIV) and the third with acute lymphoblastic leukemia. Diagnosis was confirmed by biopsy. CT disclosed a single, supratentorial, nodular-shaped lesion that substantially enhanced with contrast material, localized in parietal or frontal lobes. T1-weighted MRI showed hypointense lesions that enhanced with gadolinium-diethylenetriaminepentaacetic acid, corresponding to extensive hyperintense areas on T2-weighted images, producing mass effect. The imaging pattern of brain chagoma presented here is similar to that of cerebral toxoplasmosis and should be considered in the differential diagnosis of an intracerebral mass lesion in immunocompromised patients.     

Does brain degeneration in Wilson disease involve not only copper but also iron accumulation?

Background and purposeWilson disease (WD) is an autosomal recessive inherited disorder of hepatic copper metabolism. Clinical manifestations of WD include neurologic, hepatic and psychiatric symptoms. Most WD patients with the neuropsychiatric form, and some with the hepatic and presymptomatic forms have both hypointense and hyperintense lesions in basal ganglia on T2-weighted magnetic resonance imaging (MRI), which can be iron and copper accumulation. It has been established that T2* and susceptibility-weighted imaging (SWI) are highly sensitive in demonstrating brain iron accumulation, showing decreased signal intensity. Hypointense globus pallidus (GP) signal has been described on T2-, T2*-weighted images and on SWI as typical MRI lesion for patients with neurodegeneration with brain iron accumulation (NBIA). We investigated whether WD patients have MRI changes suggesting iron accumulation using T2*-weighted and VEN_BOLD SWI imaging protocols.Material and methodsStandard MRI with additional sequences (T2*-weighted and VEN_BOLD SWI) was performed in consecutively admitted, clinically stable, and treated patients.ResultsTwenty-eight patients entered the study. Hypointensity in the GP was observed on T2*-weighted images in 10 patients. Using the VEN_BOLD SWI technique, we found hypointense signal in GP in 20 patients.ConclusionsMRI data suggest not only copper but also iron accumulation in GP in WD patients.     

Analysis of magnetic resonance imaging (MRI) morphometry and cerebral blood flow in patients with hypoxic-ischemic encephalopathy.

The aim of this study was to analyze magnetic resonance imaging (MRI) morphometry and cerebral blood flow (CBF) in patients with hypoxic-ischemic encephalopathy, and determine the viability of such measurements for predicting cerebral outcome. The subjects were 26 patients with histories of cardiopulmonary resuscitation who had subsequently developed encephalopathy. We examined the CBF using stable xenon-computed tomography (Xe-CT) and MR images in the subacute period (8-20 days). Three signal-change patterns in the basal ganglia emerged in the MRI study. The first pattern, isointense areas evident in both the T1-weighted image (T1WI) and the T2-weighted image (T2WI), was observed in four patients with favorable outcomes. The second pattern, iso- or hypointense areas evident in the T1WI and hyperintense areas evident in the T2WI, was observed in six patients with favorable outcomes and three patients with poor outcomes. The third pattern, hyperintense areas evident in both the T1WI and T2WI, was observed in 13 patients with poor outcomes. Hemispheric CBFs were 38.9+/-4.6 (mean (SD)) ml/100 g/min in patients with favorable outcomes and 25.3+/-4.3 ml/100 g/min in patients with poor outcomes (p < 0.01). The CBF increase after acetazolamide administration was 13.3+/-3.4 ml/100 g/min in patients with favorable outcomes and 6.8+/-5.6 ml/100 g/min in patients with poor outcomes ( p < 0.05). The presence of hyperintense lesions in the basal ganglia in T1WI, low hemispheric CBF ( < 30 ml/100 g/min), and low acetazolamide reactivity ( < 10 ml/100 g/min) are all factors associated with poor outcome in patients with hypoxic-ischemic encephalopathy.     

MRI finding of CNS cryptococcosis in an HIV-positive patient]

We report an HIV-positive patient with CNS cryptococcosis, diagnosis of which was based on detection of Cryptococcus neoformans by Indian ink staining and culture of CSF. MRI displayed dilated Virchow-Robin space in bilateral basal ganglia which were hypointense on T1-weighted images, hyperintense on T2-weighted images, and enhanced by gadolinium administration. In addition cryptococcoma in the cerebellum was observed by MRI. This finding may suggest a progression from cryptococcal meningitis to intraparenchymal invasion, accompanied with breakdown of the blood brain barrier.     

MRI in neurosarcoidosis.

Nine patients with neurological manifestations of sarcoidosis were explored by MRI and, in some cases, CT. The MRI examinations were performed in T1- and T2-weighted spin-echo sequences in all patients, with gadolinium injection in seven. Several non-specific lesions were demonstrated, the most frequent of them showing on T2-weighted sequences as high-intensity signals in the periventricular white matter and the semi-oval centres. Other abnormalities, such as infiltrations of the hypothalamo-pituitary region, granulomatous masses within the brain tissue and meningeal infiltrations, were observed. These findings were in agreement with those found in the literature. Gadolinium injection seems to be important in this pathology, as it demonstrates lesions that are not visible on conventional T1- and T2-weighted spin-echo sequences.     

Magnetic resonance imaging and brain-stem auditory evoked potentials in neuro-Behcet's disease

We studied central nervous system lesions in patients with neuro-Behcet's disease using magnetic resonance imaging (MRI) of the brain and recording of brain-stem auditory evoked potentials (BAEPs). MRI revealed abnormal findings in seven of eight patients. MRI studies demonstrated extensive regions with high intensity signal in the brain stem and/or basal ganglia on T2-weighted images obtained during the acute stage of the disease in three patients. One of these patients had a strongly gadolinum-enhanced round lesion in the lower pons. In four of the other five patients with chronic disease, brain-stem atrophy was observed on T1-weighted images. Atrophic changes were more severe in the brain stem than in the cerebellum. Abnormal BAEPs were observed in three patients and consisted of prolongation of interpeak latency of waves III-V and defects of wave III or V. Abnormal BAEPs were recorded in patients with severe inflammatory changes or progression of atrophic changes in the brain stem. Our findings show that MRI and BAEPs are useful in detecting the presence and assessing the degree of neurological involvement in patients with neuro-Behcet's disease.     

Clinical lacunar syndromes as predictors of lacunar infarcts. A comparison of acute clinical lacunar syndromes and findings on diffusion-weighted MRI

OBJECTIVES: To evaluate if patients with acute lacunar syndromes have acute lacunar infarcts or other types of cerebral lesions on diffusion-weighted MRI. METHODS: Patients with acute lacunar syndromes underwent echo-planar diffusion MRI of the brain within 3 days after stroke onset. Localization and size of lesions with hyperintense signal were determined, compared with clinical characteristics and with findings on follow-up T2-weighted MRI. RESULTS: Twenty-three patients participated in the study. Thirteen patients had pure motor stroke, 1 pure sensory stroke, 8 sensorimotor stroke, and 1 ataxic hemiparesis. Twenty-two patients had at least one lesion with increased signal on diffusion-weighted MR images. These acute lesions were in the internal capsule/ basal ganglia/thalamus in 13 patients, subcortical white matter in 5 patients, brainstem in 2 patients, cortex (multiple small lesions) in 1 patient, and cortex + basal ganglia in 1 patient. The median volume of the lesions was 0.6 ml on the initial examination and on follow-up, of 17 patients after 1 to 5 months, 0.5 ml. CONCLUSIONS: Almost all patients with acute ischemic lacunar syndromes have acute lesions on echo-planar diffusion-weighted MRI within 3 days after stroke onset. These lesions are mostly small and subcortical, compatible with lacunar infarcts caused by single penetrating artery occlusion, but in a minor proportion of patients (2 of 23 in our study) a cortical involvement is found.     

Validation of hyperintense middle cerebral artery sign in acute ischemic stroke Comparison between magnetic resonance imaging and angiography

We performed a retrospective analysis of non-contrast computed tomography (CT) scans, immediately subsequent magnetic resonance imaging (MRI), and cerebral angiography data from 30 consecutive patients with acute ischemic stroke within 6 hours after symptom onset. Results showed that eleven patients developed subsequent hemorrhagic transformation at follow-up. A hyperintense middle cerebral artery sign on MRI was found in six hemorrhagic patients, all of who had acute thrombosis formation on magnetic resonance angiography and digital subtraction angiography. No patients in the non-hemorrhagic group had hyperintense middle cerebral artery sign on MRI. The sensitivity, specificity, and positive predictive values of the hyperintense middle cerebral artery sign on MRI T1-weighted image for subsequent hemorrhagic transformation were 54.5%, 100%, and 100% respectively. Hyperdense middle cerebral artery sign on non-contrast CT was observed in nine patients, five of who developed hemorrhagic transformation. These data suggest that hyperintense middle cerebral artery sign on MRI T1-weighted image is a highly specific and moderately sensitive indicator of subsequent hemorrhagic transformation in patients after acute ischemic stroke, and its specificity is superior to CT.     

MRI and CT findings in Krabbe disease

The progression and characteristics of magnetic resonance imaging (MRI) and computed tomographic (CT) findings in 3 patients with infantile Krabbe disease (i.e., globoid cell leukodystrophy or galactocerebroside beta-galactosidase deficiency) are reported. We obtained initial CT and MRI studies when patients demonstrated hyperirritability and hypertonicity. The following results facilitated early diagnoses: increased density in the thalami, corona radiata, and cerebellar cortex on CT and plaque-like, high signal intensity in the periventricular region and cerebellar white matter on MRI T2-weighted images. After severe motor and mental deterioration and spasticity had developed, progressive brain atrophy, low density in the white matter, and calcification-like, symmetric, punctate high-density areas in the corona radiata were evident on CT and high signal intensity in T2-weighted images and low signal intensity in T1-weighted images in the white matter were present on MRI. In particular, linear patterns were observed in the centrum semiovale on MRI.