Atypical posterior reversible encephalopathy syndrome in a noncompliant hemodialysis patient: Case report and literature review

Posterior reversible encephalopathy syndrome (PRES) is a reversible vasogenic brain edema in patients who present with seizure, headache, visual disturbance, and altered mental status, and a characteristic neuroimaging profile. Although PRES predominantly affects the bilateral parieto‐occipital areas, involvement of the frontal and temporal lobes, basal ganglia, brainstem, and cerebellum is not uncommon. Isolated involvement of the brainstem and cerebellum sparing the parieto‐occipital lobe is rarely reported. Here, we describe a 47‐year‐old man with end‐stage renal disease on chronic hemodialysis who presented with prominent hypertension and coma after missing three dialysis sessions. On examination, there was paucity of focal neurologic signs. Diagnosis of PRES was based on brain magnetic resonance imaging findings that were consistent with vasogenic edema of the pons and cerebellum without involvement of other areas. With antihypertensive therapy and intense ultrafiltration during hemodialysis, the patient's blood pressure and consciousness returned to normal, along with complete resolution of the abnormal imaging findings. This case stresses that noncompliance with dialysis should be considered a risk factor for PRES. This case is considered relative to the available literature on three patients with brainstem variant of PRES.     

Two additional cases of metformin‐associated encephalopathy in patients with end‐stage renal disease undergoing hemodialysis

We report on two additional cases of metformin‐associated encephalopathy in patients with end‐stage renal disease (ESRD) undergoing hemodialysis. Two patients were seen at our hospital with abnormal neurological signs and symptoms. Magnetic resonance imaging (MRI) revealed the same pattern of high signal intensity in both basal ganglia in T2‐weighted images in the two patients. The two patients had started taking metformin 5 and 6 weeks earlier at the same dose of 1000 mg per day. Metformin was immediately stopped, and regular hemodialysis was conducted. Their signs and symptoms resolved completely after these measures. The high signal intensity in both ganglia in T2‐weighted MRI also disappeared. We should suspect metformin‐induced encephalopathy and withdraw the drug when presented with diabetic patients with chronic kidney disease and neurological signs and symptoms of unknown cause.     

A comprehensive review: Segmentation of MRI images—brain tumor

Segmentation of tumors in human brain aims to classify different abnormal tissues (necrotic core, edema, active cells) from normal tissues (cerebrospinal fluid, gray matter, white matter) of the brain. In existence, detection of abnormal tissues is easy for studying brain tumor, but reproducibility, characterization of abnormalities and accuracy are complicated in the process of segmentation. The magnetic resonance imaging (MRI)‐based segmentation of tumors in brain images is more enhancing and attracting in current years of research studies. It is due to non‐invasive examination and good contrast prone to soft tissues of images obtained from MRI modality. Medical approval of different segmentation techniques depends on the benchmark and simplicity of the method. This article incorporates both fully‐automatic and semi‐automatic methods for segmentation. The outlook study of this article is to provide the summary of most significant segmentation methods of tumors in brain using MRI. © 2016 Wiley Periodicals, Inc. Int J Imaging Syst Technol, 26, 295–304, 2016     

Dialysis disequilibrium syndrome presenting as a focal neurological deficit

We report a patient suffering from chronic kidney disease who presented to us with severe pulmonary edema. His clinical, laboratory, and sonological parameters were suggestive of end-stage renal disease. Hemodialysis was initiated, and after 48 hours (3 sessions of hemodialysis) he became drowsy and a neurological examination revealed left upper limb monoplegia with left facial palsy. Urgent computerized tomography scan of the brain revealed diffuse hypodensity in the cerebral white matter bilaterally, and brain magnetic resonance imaging showed diffuse hyperintensity in the cerebral white matter bilaterally, right internal capsule and external capsule on fluid attenuated inversion recovery and T2 sequences (hypointense on T1 sequence). He made a gradual but complete neurological recovery and was discharged 2 weeks later with normal neurological status. A repeat brain magnetic resonance imaging on follow-up 6 weeks later revealed complete resolution of the white matter abnormalities.     

CT与MRI在恶性大脑中动脉梗死中的应用进展

"恶性大脑中动脉梗死"为CT及MRI影像学上脑梗死范围>大脑中动脉供血区1/2或MRI的DWI序列图像提示脑梗死体积>145mL,形成明显的水肿、占位效应,导致神经功能的快速恶化,还可发生出血性转化及致命性脑疝,病死率极高.MMI临床表现重,可有多种高危因素,其影像学表现与其病理生理特征相关.CT与MRI目前已成为MM...     

Automated brain tumour segmentation techniques— A review

Automatic segmentation of brain tumour is the process of separating abnormal tissues from normal tissues, such as white matter (WM), gray matter (GM), and cerebrospinal fluid (CSF). The process of segmentation is still challenging due to the diversity of shape, location, and size of the tumour segmentation. The metabolic process, psychological process, and detailed information of the images, are obtained using positron emission tomography (PET) image, Computer Tomography (CT) image and Magnetic Resonance Image (MRI). Multimodal imaging techniques (such as PET/CT and PET/MRI) that combine the information from many imaging techniques contribute more for accurate brain tumour segmentation. In this article, a comprehensive overview of recent automatic brain tumour segmentation techniques of MRI, PET, CT, and multimodal imaging techniques has been provided. The methods, techniques, their working principle, advantages, their limitations, and their future challenges are discussed in this article. © 2017 Wiley Periodicals, Inc. Int J Imaging Syst Technol, 27, 66–77, 2017     

多模态影像学检查在诊断早期强直性脊柱炎骶髂关节疾病中的效果

目的:探究在早期强直性脊柱炎骶髂关节疾病诊断中不同放射影像学检查方法的应用效果.方法:抽取2018年5月-2020年1月本院收治的早期强直性脊柱炎骶髂关节疾病患者65例作为研究对象,所有患者均开展X线、CT、MRI影像学检查,对比三种不同影像学检查方法的检出率、影像学特征.结果:X线、CT、MRI检出率分别为38.46...     

MRI、CT与全数字化乳腺X线摄影在乳腺癌诊断中的临床价值分析

目的:分析讨论乳腺癌诊断中应用MRI、CT和全数字化乳腺X线摄影的临床应用价值。方法:选取本院2017年1月-2018年12月乳腺疾病患者200例,对所有研究对象先后进行MRI、CT和全数字化乳腺X线摄影检查。比较三种检查方式对乳腺癌的诊断率。结果:MRI、CT和全数字化乳腺X线摄影诊断率依次为93.00%、80.50%和77.50%,MRI诊断率明显高于CT和全数字化乳腺X线摄影,P<0.05。结论:MRI能够有效诊断乳腺癌,但MRI检查费用较高,可优先使用CT和全数字化乳腺X线摄影检查。     

医学影像新技术在脑血管病诊断中的应用

本文综述了第四届全国脑血管病学术会议有关影像学检查,包括MRI、CT、SPECT、TCD等在脑血管病诊断方面的有关内容,MRI在发现早期脑梗塞方面较CT优越,CT依然是诊断脑梗塞及脑出血的主要检查手段,SPECT及TCD对缺血性脑血管病的诊断有很大帮助,合理选择以上检查方法对脑血管病的早期诊断、指导治疗、判断预后及随访有重要意义。     

Thrombosis of the great cerebral vein in a hemodialysis patient

Cerebral venous thrombosis is a rare condition with various clinical presentations which may delay diagnosis. It is frequently associated with severe consequences. We present the first documented case of thrombosis of the great cerebral vein in a hemodialysis patient. A 29‐year‐old female patient with end‐stage renal disease of unknown etiology was admitted to a hospital with altered consciousness and nausea. Severe headache in the right parietal area had started 2 days before. On examination, she was in the poor overall condition, dysartric, with a severe nystagmus. Urgent brain multislice computerized tomography and magnetic resonance imaging revealed thrombosis of the great cerebral vein with hypodense zones in hypothalamus, thalamus and basal ganglia. She was treated with heparin bolus of 25000 IU with a favorable outcome. Detailed examination demonstrated increased lupus anticoagulant (LA) 1 and LA2 and increased LA1/LA2. Control magnetic resonance imaging performed 1 year later revealed multiple vascular lesions within the brain. Acetylsalicylate was introduced in therapy. Thrombosis of the cerebral veins should be suspected in patients with end‐stage renal disease, altered neurological status and signs of increased intracranial pressure.     

磁敏感成像在脑微出血诊断中的应用价值要求

目的:探讨磁敏感成像在脑微出血诊断中的应用价值.方法:127例疑似脑微出血患者分别行MRI常规序列扫描和SWI序列扫描,比较各序列检出CMBs阳性例数以及脑微出血灶的数量、位置分布的显示情况.结果:97例颅内检出微出血病灶,SWI序列检出低信号灶1418个,CMBs阳性检出率100％,显著高于常规序列检出率76.5％(P＜0.01).结论:磁敏感成像技术对于脑微出血的显示具有高度敏感性,为目前检出脑微出血的最佳序列.     

Assessment of cerebral blood perfusion changes after neurorehabilitation therapy in patients with middle cerebral artery infarction: An acetazolamide‐challenged SPECT study

Stroke is a leading cause of death and disability worldwide. Although neuroimaging has been used to examine brain changes related to recovery from stroke, cerebral perfusion changes after rehabilitation have yet to be elucidated. The aim of this study was to evaluate the regional cerebral blood flow (rCBF) changes and their associations with gross motor functions after neurorehabilitation therapy in stroke patients. A total of 7 patients with middle cerebral artery (MCA) infarction received conventional neurorehabilitation therapy twice per day for 4‐6 weeks on admission. Brain perfusion images were acquired before and after the therapy using acetazolamide‐challenged single photon emission computed tomography. A whole‐brain voxel‐wise analysis found increased rCBF in the contralesional prefrontal, precentral, and postcentral cortical areas and decreased rCBF in the ipsilesional insula, posterior orbital gyrus, and central operculum. Moreover, a region of interest analysis revealed that rCBF of the ipsilesional basal ganglia was positively correlated with motor function at baseline and follow‐up, and perfusion changes in the ipsilesional basal ganglia was positively correlated with changes in motor function. These findings suggest that the contralesional prefrontal and sensorimotor cortex may play compensatory roles during the motor recovery and that perfusion in the ipsilesional basal ganglia is closely associated not only with current functional status but also with clinical improvement after neurorehabilitation therapy in patients with MCA infarction. Further studies with larger sample size are warranted to investigate whether assessment of cerebral perfusion may be clinically useful in rehabilitation of stroke patients.     

X线胸片与常规CT、HRCT对矽肺及其合并症诊断的对比分析

目的:比较X线胸片与CT、HRCT对矽肺及其合并症的诊断作用,并对不同诊断结果进行分析。方法:选取2008年1月-2013年1月我院收治的矽肺患者100例为研究对象,所有患者均行X线胸片、CT、HRCT检查,对三种影像学检查结果进行比较分析。结果:HRCT对于小阴影、肺气肿、肺间质纤维化的影像特征明显优于CT与X线胸片;而X线胸片对于大阴影的显示、肺气肿、肺间质纤维化、胸膜改变的影像特征表现略差于CT、HRCT。结论:CT对于矽肺的诊断具有一定的临床意义,特别是HRCT,而结合X线胸片能进一步对矽肺病变部位进行准确的分析。     

Amphiphilic polymer-coated hybrid nanoparticles as CT/MRI dual contrast agents

We describe hybrid nanoparticles, composed of iron oxide and gold nanoparticles, as potential dual contrast agents for both computed tomography (CT) and magnetic resonance imaging (MRI). The hybrid nanoparticles are synthesized by thermal decomposition of mixtures of Fe-oleate and Au-oleylamine complexes. Using a nano-emulsion method, the nanoparticles are coated with amphiphilic poly(DMA-r-mPEGMA-r-MA) to impart water-dispersity and antibiofouling properties. An in?vitro phantom study shows that the hybrid nanoparticles have high CT attenuation, because of the constituent gold nanoparticles, and afford a good MR signal, attributable to the contained iron oxide nanoparticles. Intravenous injection of the hybrid nanoparticles into hepatoma-bearing mice results in high contrast between the hepatoma and normal hepatic parenchyma in both CT and MRI. These results suggest that the hybrid nanoparticles may be useful as CT/MRI dual contrast agents for in?vivo hepatoma imaging.     

Fully automatic method for segmentation of brain tumor from multimodal magnetic resonance images using wavelet transformation and clustering technique

Fully automatic brain tumor segmentation is one of the critical tasks in magnetic resonance imaging (MRI) images. This proposed work is aimed to develop an automatic method for brain tumor segmentation process by wavelet transformation and clustering technique. The proposed method using discrete wavelet transform (DWT) for pre‐ and post‐processing, fuzzy c‐means (FCM) for brain tissues segmentation. Initially, MRI images are preprocessed by DWT to sharpen the images and enhance the tumor region. It assists to quicken the FCM clustering technique and classified into four major classes: gray matter (GM), white matter (WM), cerebrospinal fluid (CSF), and background (BG). Then check the abnormality detection using Fuzzy symmetric measure for GM, WM, and CSF classes. Finally, DWT method is applied in segmented abnormal region of images respectively and extracts the tumor portion. The proposed method used 30 multimodal MRI training datasets from BraTS2012 database. Several quantitative measures were calculated and compared with the existing. The proposed method yielded the mean value of similarity index as 0.73 for complete tumor, 0.53 for core tumor, and 0.35 for enhancing tumor. The proposed method gives better results than the existing challenging methods over the publicly available training dataset from MICCAI multimodal brain tumor segmentation challenge and a minimum processing time for tumor segmentation. © 2016 Wiley Periodicals, Inc. Int J Imaging Syst Technol, 26, 305–314, 2016     

CT检查在霉菌性鼻窦炎中的诊断价值研究

目的:研究CT检查在霉菌性鼻窦炎中的诊断价值。方法:回顾性分析2012年1月-2013年1月在我院行CT扫描并均经病理证实为霉菌性鼻窦炎患者60例,分析这些患者的CT检查影像资料,主要观察患者CT显示的霉菌性鼻窦炎的病变范围、病变区的密度、病变部位鼻窦骨壁的骨质情况。结果:霉菌性鼻窦炎CT影像学表现的主要为:病变部位主要好发于上颌窦,常局限于单侧;鼻窦腔内的软组织影像呈现斑点状的钙化散在的影像;病变一侧的鼻窦窦口较对侧增大,使受累侧的正常组织结构受压移位;病变部位鼻窦骨壁的骨质增厚、硬化,骨质被破坏。结论:霉菌性鼻窦炎具有一定的CT影像学特征,CT检查可有效的诊断霉菌性鼻窦炎,可确定病变范围及病变程度,并有助于与其他疾病的鉴别诊断,对临床上诊断该病具有重要的价值。     

MRI在宫颈癌患者术前诊断中的临床价值

目的:探讨MRI在宫颈癌患者术前诊断中的临床价值。方法:本研究选取本院妇科2016年1月至2018年12月之间收治120例疑似宫颈癌患者的临床资料进行对照性分析。结果:实验组诊断符合率为95.5%明显高于对照组的65.0%(P<0.05)。MRI对于阴道浸润、子宫体侵犯检查的特异性和敏感性均明显高于CT检查,而盆腔淋巴结转移则低于CT检查(P<0.05)。结论:在宫颈癌检查和诊断中应用MRI技术,具有较高的诊断准确性,对于疾病特征检查的特异性和敏感性较高。     

The nature,consequences, and management of neurological disorders in chronic kidney disease

Perhaps no other organ in the body is affected as often and in as many ways as the brain is in patients with chronic kidney disease (CKD). Several factors contribute to the neurological disorders in CKD including accumulation of uremic toxins, metabolic and hemodynamic disorders, oxidative stress, inflammation, and impaired blood brain barrier among others. The neurological disorders in CKD involve both peripheral and central nervous system. The peripheral neurological symptoms of CKD are due to somatic and cranial peripheral neuropathies as well as a myopathy. The central neurological symptoms of CKD are due to the cortical predominantly cortical, or subcortical lesions. Cognitive decline, encephalopathy, cortical myoclonus, asterixis and epileptic seizures are distinct features of the cortical disorders of CKD. Diffuse white matter disease due to ischemia and hypoxia may be an important cause of subcortical encephalopathy. A special and more benign form of subcortical disorder caused by brain edema in CKD is termed posterior reversible encephalopathy. Subcortical pathology especially when it affects the basal ganglia causes a number of movement disorders including Parkinsonism, chorea and dystonia. A stimulus‐sensitive reflex myoclonus is believed to originate from the medullary structures. Sleep disorder and restless leg syndrome are common in CKD and have both central and peripheral origin. This article provides an overview of the available data on the nature, prevalence, pathophysiology, consequences and treatment of neurological complications of CKD.     

Compatible abnormality detection technique for CT and MRI brain images

Abstract

An automated computerised tomography (CT) and magnetic resonance imaging (MRI) brain images are used to perform an efficient classification. The proposed technique consists of three stages, namely, pre-processing, feature extraction and classification. Initially, pre-processing is performed to remove the noise from the medical MRI images. Then, in the feature extraction stage, the features that are related with MRI and CT images are extracted and these extracted features which are given to the Feed Forward Back-propagation Neural Network (FFBNN) is exploited in order to classify the brain MRI and CT images into two types: normal and abnormal. The FFBNN is well trained by the extracted features and uses the unknown medical brain MRI images for classification in order to achieve better classification performance. The proposed method is validated by various MRI and CT scan images. A classification with an accomplishment of 96% and 70% has been obtained by the proposed FFBNN classifier. This achievement shows the effectiveness of the proposed brain image classification technique when compared with other recent research works.     

炫速双源CT行头部血管双能量成像对辐射剂量与图像质量的影响研究

目的:研究炫速双源CT行头部血管双能量成像的价值.方法:选择本院2021年6月-12月纳入的106例脑血管病变患者,按随机数字表法分为两组各53例,研究组开展炫速双源CT的头部血管双能量成像,对照组开展常规双源CT的头部血管双能量成像,对比两组CT剂量指数、有效剂量、剂量长度乘积,比较不同脑血管的CT值以及不同平面的图...