3D Brain Tumor Image Segmentation Integrating Cascaded Anisotropic Fully Convolutional Neural Network and Hybrid Level Set Method

To evaluate the inner ear of a patient with an enlarged vestibular aqueduct and acute hearing deterioration, using three-dimensional fluid-attenuated inversion recovery (3D FLAIR) magnetic resonance imaging (MRI). Three-dimensional fluid-attenuated inversion recovery MRI has been recently developed to detect haemorrhage and high concentrations of protein. Application of this method to inner-ear diseases has not been fully described. We used 3D FLAIR MRI to evaluate a patient with an enlarged vestibular aqueduct and acute hearing deterioration. On 3D FLAIR MRI, this patient had high signals in the endolymphatic duct and sac, the vestibule and the cochlea and was diagnosed as having a high protein concentration in the inner ear. These high signal areas were not detected by T1- and T2-weighted MRI. This is the first published case in which a high protein concentration in the cochlea of a patient with an enlarged vestibular aqueduct was detected by 3D FLAIR MRI. These findings strongly supported the theory of the pathophysiology of hearing deterioration in patients with an enlarged vestibular aqueduct, which states that hyperosmolar fluid in the enlarged endolymphatic sac refluxes into the cochlea, resulting in damage to the hair cells. Thus, these finding may help clarify the cause of hearing deterioration in the presence of a large endolymphatic duct and sac.

The diagnostic efficacy of fluid-attenuated inversion recovery (FLAIR) magnetic resonance imaging and computed tomography (CT) for acute subarachnoid hemorrhage (SAH) were compared and the problems with diagnosis were investigated in 81 patients with aneurysmal SAH within 24 hours after onset who underwent FLAIR imaging and CT on admission. The number of hematomas in the cisterns and ventricles were evaluated by clot scores. In addition, the frequency of undetected hematomas was calculated for the cisterns and ventricles. Clot scores were significantly higher for FLAIR imaging than for CT in the lateral sylvian, quadrigeminal, and convexity cisterns. On the other hand, clot scores were significantly higher for CT than for FLAIR imaging in the interhemispheric and medial sylvian cisterns. The overall frequency of undetected SAH was 2% for FLAIR imaging and 14% for CT. With the exception of the interhemispheric and medial sylvian cisterns, the frequency of undetected SAH was higher for CT than for FLAIR imaging. In this study, FLAIR imaging was more sensitive than CT for the detection of acute SAH within 24 hours after onset. However, the diagnostic efficacy of FLAIR imaging was reduced in comparatively tight cisterns.

A Validation Framework for Brain Tumor Segmentation

As one of the fatal human diseases, early detection of brain tumors can effectively save patients’ lives. Brain tumor image segmentation is of great practical importance for physicians to perform brain tumor diagnoses quickly. Due to the data complexity of 3D brain images, it is impractical to segment out tumor regions manually, so automatic and reliable methods can be utilized instead of manual work to achieve accurate segmentation of tumor regions. In this paper, we propose an end-to-end, more efficient brain tumor MRI segmentation model, REMU-Net, for the problems of multi-scale feature extraction and difficulty in small target feature extraction in 3D brain tumor image segmentation. Firstly, design and use the multi-channel parallel M-RepVGG module as a decoder to achieve multi-scale feature fusion. Secondly, embedding dilated convolution with different dilated rates in the DM-RepVGG module of the encoder to better extract features at different scales. Finally, introduce the expectation-maximizing attention in the network to better extract the features of the internal details of the tumor. The experimental results on the BraTS2018 validation dataset are Dice scores of 80.93%, 90.13%, and 86.15%, respectively. Experimental results on the BraTS2019 validation dataset can be achieved with Dice scores of 78.29%, 90.65%, and 82.77%, respectively.

Our primary objective was to investigate a biomarker driven model for the interrelationships between vascular disease pathology, amyloid pathology, and longitudinal cognitive decline in cognitively normal elderly subjects between 70 and 90 years of age. Our secondary objective was to investigate the beneficial effect of cognitive reserve on these interrelationships. We used brain amyloid-β load measured using Pittsburgh compound B positron emission tomography as a marker for amyloid pathology. White matter hyperintensities and brain infarcts were measured using fluid-attenuated inversion recovery magnetic resonance imaging as a marker for vascular pathology. We studied 393 cognitively normal elderly participants in the population-based Mayo Clinic Study of Aging who had a baseline 3 T fluid-attenuated inversion recovery magnetic resonance imaging assessment, Pittsburgh compound B positron emission tomography scan, baseline cognitive assessment, lifestyle measures, and at least one additional clinical follow-up. We classified subjects as being on the amyloid pathway if they had a global cortical amyloid-β load of ≥1.5 standard uptake value ratio and those on the vascular pathway if they had a brain infarct and/or white matter hyperintensities load ≥1.11% of total intracranial volume (which corresponds to the top 25% of white matter hyperintensities in an independent non-demented sample). We used a global cognitive z-score as a measure of cognition. We found no evidence that the presence or absence of vascular pathology influenced the presence or absence of amyloid pathology and vice versa, suggesting that the two processes seem to be independent. Baseline cognitive performance was lower in older individuals, in males, those with lower education/occupation, and those on the amyloid pathway. The rate of cognitive decline was higher in older individuals (P < 0.001) and those with amyloid (P = 0.0003) or vascular (P = 0.0037) pathologies. In those subjects with both vascular and amyloid pathologies, the effect of both pathologies on cognition was additive and not synergistic. For a 79-year-old subject, the predicted annual rate of global z-score decline was -0.02 if on neither pathway, -0.07 if on the vascular pathway, -0.08 if on the amyloid pathway and -0.13 if on both pathways. The main conclusions of this study were: (i) amyloid and vascular pathologies seem to be at least partly independent processes that both affect longitudinal cognitive trajectories adversely and are major drivers of cognitive decline in the elderly; and (ii) cognitive reserve seems to offset the deleterious effect of both pathologies on the cognitive trajectories.

To verify the hypothesis that intravenous frusemide reduces endolymphatic hydrops, as evaluated by three-dimensional fluid-attenuated inversion recovery magnetic resonance imaging following intratympanic gadolinium administration. The study comprised 12 patients (7 females and 5 males, aged 19-74 years) with Ménière's disease. Disease duration ranged from 0.5 to 8 years, with a frequency of 0.5 to 6 vertigo spells per month, as calculated in the last 6 months. Three-dimensional fluid-attenuated inversion recovery magnetic resonance imaging was performed 24 hours after intratympanic injection of gadobutrol diluted eight-fold. Frusemide 20 mg was given intravenously immediately after imaging. Magnetic resonance imaging was repeated after 1 hour, using the same parameters and sequence. All patients showed enhancement defects, indicating endolymphatic hydrops of variable degrees. No modifications occurred at the second magnetic resonance imaging performed 1 hour after frusemide administration. There was no evidence of endolymphatic hydrops modification 1 hour after intravenously administered frusemide. Therefore, loop diuretics in Ménière's disease, which are today used on an empirical basis, must be reconsidered. Implications of these outcomes are discussed and related to the role of endolymphatic hydrops in the development of Ménière's disease.

White matter hyperintensities (WMHs) are regions of abnormally high intensity on T2-weighted or fluid-attenuated inversion recovery (FLAIR) magnetic resonance imaging (MRI). Accurate and reproducible automatic segmentation of WMHs is important since WMHs are often seen in the elderly and are associated with various geriatric and psychiatric disorders. We developed a fully automated monospectral segmentation method for WMHs using FLAIR MRIs. Through this method, we introduce an optimal threshold intensity (I O ) for segmenting WMHs, which varies with WMHs volume (V WMH), and we establish the I O -V WMH relationship. Our method showed accurate validations in volumetric and spatial agreements of automatically segmented WMHs compared with manually segmented WMHs for 32 confirmatory images. Bland-Altman values of volumetric agreement were 0.96 ± 8.311ml (bias and 95% confidence interval), and the similarity index of spatial agreement was 0.762 ± 0.127 (mean ± standard deviation). Furthermore, similar validation accuracies were obtained in the images acquired from different scanners. The proposed segmentation method uses only FLAIR MRIs, has the potential to be accurate with images obtained from different scanners, and can be implemented with a fully automated procedure. In our study, validation results were obtained with FLAIR MRIs from only two scanner types. The design of the method may allow its use in large multicenter studies with correct efficiency.

Automated segmentation of brain tumour from multimodal MR images is pivotal for the analysis and monitoring of disease progression. As gliomas are malignant and heterogeneous, efficient and accurate segmentation techniques are used for the successful delineation of tumours into intra-tumoural classes. Deep learning algorithms outperform on tasks of semantic segmentation as opposed to the more conventional, context-based computer vision approaches. Extensively used for biomedical image segmentation, Convolutional Neural Networks have significantly improved the state-of-the-art accuracy on the task of brain tumour segmentation. In this paper, we propose an ensemble of two segmentation networks: a 3D CNN and a U-Net, in a significant yet straightforward combinative technique that results in better and accurate predictions. Both models were trained separately on the BraTS-19 challenge dataset and evaluated to yield segmentation maps which considerably differed from each other in terms of segmented tumour sub-regions and were ensembled variably to achieve the final prediction. The suggested ensemble achieved dice scores of 0.750, 0.906 and 0.846 for enhancing tumour, whole tumour, and tumour core, respectively, on the validation set, performing favourably in comparison to the state-of-the-art architectures currently available.

Image fusion of fluid-attenuated inversion recovery magnetic resonance imaging sequences for surgical image guidance

Images in Clinical Neurology The Neurohospitalist 2017, Vol. 7(1) 49-50 a The Author(s) 2016 Reprints and permission: sagepub.com/journalsPermissions.nav DOI: 10.1177/1941874416637407 journals.sagepub.com/home/nhos Wernicke-Like Encephalopathy Associated With Ifosfamide John Kent Lin, MD 1 , Daniel S. Chow, MD 2 , Leslie Sheu, MD 1 , and Bhavya Rehani, MD 2 Keywords imaging, Wernicke encephalopathy, dyskinesia, drug induced A 73-year-old female with maxillary chondroblastic sarcoma, chronic kidney disease, and undernutrition presented with ataxia, myoclonus, and confusion 1 week after ifosfamide and etoposide. Three days later, she became obtunded. Magnetic resonance imaging of the brain revealed abnorm- alities in the bilateral thalami (Figure 1) and mammillary bod- ies (Figure 2), suggestive of thiamine deficiency. Treatment dose of intravenous thiamine was administered, and her neu- rologic status normalized within 24 hours. Ifosfamide rarely causes a Wernicke-like encephalopathy, particularly in patients with sarcoma, elevated creatinine, and hypoalbuminemia. 1 Toxicity is likely mediated through its metabolite Chloroacetaldehyde, which may impair thiamine function, and is treated with methylene blue or thiamine. 2 Figure 2. Axial fluid-attenuated inversion recovery (FLAIR) magnetic resonance (MR) image demonstrates increased signal intensity in the mammillary bodies, bilaterally (arrows). Author’s Note John Kent Lin, Daniel Chow, Leslie Sheu, and Bhavya Rehnai contrib- uted to drafting or revising the manuscript for intellectual content. Bha- vya Rehani is the corresponding author, principal author, and guarantor. Department of Medicine, University of California–San Francisco, San Fran- cisco, CA, USA Department of Radiology and Biomedical Imaging, University of California– San Francisco, San Francisco, CA, USA Figure 1. Axial fluid-attenuated inversion recovery (FLAIR) magnetic resonance (MR) image demonstrates increased signal intensity involving the thalami, bilaterally (arrows). Corresponding Author: Bhavya Rehani, University of California–San Francisco, 505 Parnassus Ave, San Francisco, CA 94143, USA. Email: bhavya.rehani@ucsf.edu

Cyclosporine-Related Posterior Reversible Encephalopathy Syndrome After Heart Transplantation: Should We Withdraw or Reduce Cyclosporine?: Case Reports

Progressive hearing loss following acquired cytomegalovirus infection in an immunocompromised child

Background High signals in the inner ear of idiopathic sudden sensorineural hearing loss (ISSNHL) on magnetic resonance imaging (MRI) have been reported, but no quantitative evaluation has yet been done. Objectives To evaluate hearing outcomes and cochlear signal intensities on 3-T heavily T2-weighted three-dimensional fluid-attenuated inversion recovery magnetic resonance imaging (hT2W-3D-FLAIR) in patients with ISSNHL. Materials and methods Twenty-nine patients with ISSNHL were included. Patients underwent hT2W-3D-FLAIR with intravenous gadolinium injection and pure tone audiometry (PTA) at initial visits and 3 months later. Signal intensity ratios (SIRs) were measured in the basal or apical-middle turns of the affected cochlea. A statistical analysis of relationships between SIRs and the average hearing levels (HLs) at low (125, 250, and 500 Hz) and high (2, 4, and 8 kHz) tone frequencies was performed. Results Hearing improvements at high-tone frequencies in ears with HLs ≥60 dB were significantly worse in those with high SIRs at the basal turns on pre-contrast images. Similarly, hearing improvements at low-tone frequencies in ears with HLs ≥60 dB were significantly worse in those with high SIRs at the apical-middle turns on post-contrast images. Conclusions and significance High SIRs on hT2W-3D-FLAIR indicate cochlear disturbances with severe ISSNHL and could provide lesion-specific prognostic information.

Cerebral Autosomal Dominant Arteriopathy With Subcortical Infarcts and Leukoencephalopathy Associated With a Novel In-Frame Mutation in the NOTCH3 Gene in a Japanese Patient

Objective To elucidate significance of hyperintense vessel signs(HVS)on FLAIR MRI in patients with cerebral infarction. Methods Two hundred and sixty-two patients with cerebral infarction admitted in our hospital were included in this study. We retrospectively defined HVS on FLAIR MRI in these patients in comparison with time of flight(TOF)on MR angiograms(MRA), hyperintense lesions on diffusion-weighted images(DWI). Results HVS on FLAIR MR[were identified in 117 patients with cerebral infarction(45.4%), of which 47 patients(83.9%)were obtained within 24 hours of symptom onset. HVS on FLAIR MRI were detected in 74 patients at sylvian fissure(62.2%), 11 at cortical sulci (9.2% ,11/119),34 at the posterior circulation regions(28.6% ,34/119). HVS on FLAIR MRI coincided well with ischemia of TOF on MRA and lesion patterns on DWI (χ2 test,P<0.01, respectively). Conclusion HVS on FLAIR MRI is helpful to evaluate abnormal major cerebral arteries of patients with cerebral infarction. Key words: Brain infarction; Magnetic resonance imaging