RESUMEN
Cognitive impairment in focal cerebellar disorders has been widely recognized and is described as cerebellar cognitive affective syndrome (CCAS). However, the relationship between CCAS and crossed cerebello-cerebral diaschisis (CCD) has rarely been discussed. The present report describes the uncommon phenomenon of CCD in two cases with isolated cerebellar infarction, and discuss its contribution to cognitive impairment. Cognitive performance was examined using the CCAS scale and a battery of neuropsychological assessments. Moreover, the relative distribution of cerebral and cerebellar blood flow was measured using three-dimensional arterial spin labeling imaging. Case 1 showed deficits in general cognition and had impaired language, episodic memory, and executive function. Case 2 showed deficits in general cognition at baseline, and cognitive deterioration of visuospatial abilities, language, episodic memory, and executive function was observed at the 3-month follow-up. Both cases met the diagnosis criteria of CCAS. Reduced cerebral blood flow was observed in the cerebral hemisphere contralateral to the cerebellar infarction at baseline in Case 1, and at the 3-month follow-up in Case 2. The present report describes cognitive decline after isolated cerebellar infarction in combination with contralateral cerebral hypoperfusion, as measured using quantitative arterial spin labeling. One possible mechanism involves the functional depression of cerebello-cerebral pathways.
Asunto(s)
Isquemia Encefálica , Enfermedades Cerebelosas , Disfunción Cognitiva , Humanos , Enfermedades Cerebelosas/complicaciones , Enfermedades Cerebelosas/diagnóstico por imagen , Cerebelo/diagnóstico por imagen , Disfunción Cognitiva/complicaciones , Circulación Cerebrovascular/fisiología , InfartoRESUMEN
Gestational diabetes mellitus (GDM) is an unique metabolic disorder that occurs during pregnancy. Both GDM and advanced age increase the risk of adverse pregnancy outcomes. This study used a GDM cohort study to investigate the role of age in the adverse pregnancy outcomes for pregnant women with GDM. From 2015 to 2021, 308,175 pregnant women were selected, and the data received from 22 hospitals by the Hebei Province Maternal Near Miss Surveillance System. There were 24,551 pregnant women with GDM that were divided into five groups by age (20-24, 25-29, 30-34, 35-39, 40-44 years old). Because the prevalence of adverse pregnancy outcomes was lower in pregnant women with GDM aged 25-29, they were used as a reference group (P < 0.05). Compared with GDM women aged 25-29 years, GDM women aged 35-44 years had a significant higher risk of cesarean delivery (aOR: 2.86, 95% CI 2.52-3.25) (P < 0.001), abnormal fetal position (aOR: 1.78, 95% CI 1.31-2.37) (P < 0.001), pre-eclampsia (aOR: 1.28, 95% CI 1.01-1.61) (P < 0.05), macrosomia (aOR: 1.25, 95% CI 1.08-1.45) (P < 0.05), and large for gestational age (LGA) (aOR: 1.16, 95% CI 1.02-1.31) (P < 0.05), GDM women aged 40-44 years had a higher risk of placenta previa (aOR: 2.53, 95% CI 1.01-6.35) (P < 0.05), anemia (aOR: 3.45, 95% CI 1.23-9.68) (P < 0.05) and small for gestational age (aOR: 1.32, 95% CI 1.01-1.60) (P < 0.05). Advanced maternal age was an independent risk factor for abnormal fetal position, pre-eclampsia, anemia, macrosomia, and LGA in pregnant women with GDM.
Asunto(s)
Anemia , Diabetes Gestacional , Preeclampsia , Humanos , Embarazo , Femenino , Adulto , Diabetes Gestacional/epidemiología , Resultado del Embarazo , Mujeres Embarazadas , Macrosomía Fetal/epidemiología , Estudios de Cohortes , Preeclampsia/epidemiología , China/epidemiología , Aumento de Peso , Anemia/complicaciones , Anemia/epidemiologíaRESUMEN
The widely deployed ways to capture a set of unorganized points, e.g., merged laser scans, fusion of depth images, and structure-from- x , usually yield a 3-D noisy point cloud. Accurate normal estimation for the noisy point cloud makes a crucial contribution to the success of various applications. However, the existing normal estimation wisdoms strive to meet a conflicting goal of simultaneously performing normal filtering and preserving surface features, which inevitably leads to inaccurate estimation results. We propose a normal estimation neural network (Norest-Net), which regards normal filtering and feature preservation as two separate tasks, so that each one is specialized rather than traded off. For full noise removal, we present a normal filtering network (NF-Net) branch by learning from the noisy height map descriptor (HMD) of each point to the ground-truth (GT) point normal; for surface feature recovery, we construct a normal refinement network (NR-Net) branch by learning from the bilaterally defiltered point normal descriptor (B-DPND) to the GT point normal. Moreover, NR-Net is detachable to be incorporated into the existing normal estimation methods to boost their performances. Norest-Net shows clear improvements over the state of the arts in both feature preservation and noise robustness on synthetic and real-world captured point clouds.
RESUMEN
BACKGROUND: Anaemia in pregnancy is one of the most frequent complications related to pregnancy and is a public health concern. This article examines the prevalence of anaemia in the third trimester of pregnancy and the associations between anaemia and adverse perinatal outcomes in Hebei Province, China. METHODS: We used SPSS software to describe the incidence of anaemia in the third trimester of pregnancy in Hebei Province and analysed the clinical characteristics in anaemic patients and the relationship between anaemia and adverse pregnancy outcomes. RESULTS: The overall prevalence of anaemia in the third trimester of pregnancy was 35.0% in Hebei Province. The prevalence of anaemia in the population with a high education level was lower than that in the population with a low education level. The incidence rate in rural areas was higher than that in urban areas. After adjustment for confounding factors, anaemia in the third trimester of pregnancy is an independent risk factor in terms of placenta previa, placental abruption, uterine atony, pre-eclampsia, gestational diabetes mellitus, heart disease, postpartum haemorrhage, premature birth, laceration of birth canal, puerperal infection, caesarean section and large for gestational age. CONCLUSIONS: The prevalence of anaemia in the third trimester of pregnancy is associated with an increased risk of adverse perinatal outcomes. A comprehensive approach to prevent anaemia is needed to improve maternal and child health outcomes.
Asunto(s)
Anemia , Cesárea , Niño , Embarazo , Humanos , Femenino , Tercer Trimestre del Embarazo , Cesárea/efectos adversos , Prevalencia , Placenta , Resultado del Embarazo/epidemiología , Anemia/epidemiologíaRESUMEN
OBJECTIVES: To investigate glymphatic function in Alzheimer's disease (AD) using the diffusion tensor image analysis along the perivascular space (DTI-ALPS) method and to explore the associations between DTI-ALPS index and perivascular space (PVS) volume, as well as between DTI-ALPS index and cognitive function. METHODS: Thirty patients with PET-CT-confirmed AD (15 AD dementia; 15 mild cognitive impairment due to AD) and 26 age- and sex-matched cognitively normal controls (NCs) were included in this study. All participants underwent neurological MRI and cognitive assessments. Bilateral DTI-ALPS indices were calculated. PVS volume fractions were quantitatively measured at three locations: basal ganglia (BG), centrum semiovale, and lateral ventricle body level. DTI-ALPS index and PVS volume fractions were compared among three groups; correlations among the DTI-ALPS index, PVS volume fraction, and cognitive scales were analyzed. RESULTS: Patients with AD dementia showed a significantly lower DTI-ALPS index in the whole brain (p = 0.009) and in the left hemisphere (p = 0.012) compared with NCs. The BG-PVS volume fraction in patients with AD was significantly larger than the fraction in NCs (p = 0.045); it was also negatively correlated with the DTI-ALPS index (r = - 0.433, p = 0.021). Lower DTI-ALPS index was correlated with worse performance in the Boston Naming Test (ß = 0.515, p = 0.008), Trail Making Test A (ß = - 0.391, p = 0.048), and Digit Span Test (ß = 0.408, p = 0.038). CONCLUSIONS: The lower DTI-ALPS index was found in patients with AD dementia, which may suggest impaired glymphatic system function. DTI-ALPS index was correlated with BG-PVS enlargement and worse cognitive performance in certain cognitive domains. CLINICAL RELEVANCE STATEMENT: Diffusion tensor image analysis along the perivascular space index may be applied as a useful indicator to evaluate the glymphatic system function. The impaired glymphatic system in patients with Alzheimer's disease (AD) dementia may provide a new perspective for understanding the pathophysiology of AD. KEY POINTS: ⢠Patients with Alzheimer's disease dementia displayed a lower diffusion tensor image analysis along the perivascular space (DTI-ALPS) index, possibly indicating glymphatic impairment. ⢠A lower DTI-ALPS index was associated with the enlargement of perivascular space and cognitive impairment. ⢠DTI-ALPS index could be a promising biomarker of the glymphatic system in Alzheimer's disease dementia.
Asunto(s)
Enfermedad de Alzheimer , Disfunción Cognitiva , Sistema Glinfático , Humanos , Sistema Glinfático/diagnóstico por imagen , Enfermedad de Alzheimer/complicaciones , Enfermedad de Alzheimer/diagnóstico por imagen , Tomografía Computarizada por Tomografía de Emisión de Positrones , Cognición , Disfunción Cognitiva/complicaciones , HipertrofiaRESUMEN
OBJECTIVE: Convolutional neural network (CNN), a classical structure in deep learning, has been commonly deployed in the motor imagery brain-computer interface (MIBCI). Many methods have been proposed to evaluate the vulnerability of such CNN models, primarily by attacking them using direct temporal perturbations. In this work, we propose a novel attacking approach based on perturbations in the frequency domain instead. METHODS: For a given natural MI trial in the frequency domain, the proposed approach, called frequency domain channel-wise attack (FDCA), generates perturbations at each channel one after another to fool the CNN classifiers. The advances of this strategy are two-fold. First, instead of focusing on the temporal domain, perturbations are generated in the frequency domain where discriminative patterns can be extracted for motor imagery (MI) classification tasks. Second, the perturbing optimization is performed based on differential evolution algorithm in a black-box scenario where detailed model knowledge is not required. RESULTS: Experimental results demonstrate the effectiveness of the proposed FDCA which achieves a significantly higher success rate than the baselines and existing methods in attacking three major CNN classifiers on four public MI benchmarks. CONCLUSION: Perturbations generated in the frequency domain yield highly competitive results in attacking MIBCI deployed by CNN models even in a black-box setting, where the model information is well-protected. SIGNIFICANCE: To our best knowledge, existing MIBCI attack approaches are all gradient-based methods and require details about the victim model, e.g., the parameters and objective function. We provide a more flexible strategy that does not require model details but still produces an effective attack outcome.
Asunto(s)
Algoritmos , Interfaces Cerebro-Computador , Imaginación , Redes Neurales de la Computación , Humanos , Imaginación/fisiología , Seguridad Computacional , Procesamiento de Señales Asistido por ComputadorRESUMEN
BACKGROUND: Preliminary evidence suggests that several headache disorders may be associated with glymphatic dysfunction. However, no studies have been conducted to examine the glymphatic activity in migraine chronification. PURPOSES: To investigate the glymphatic activity of migraine chronification in patients with episodic migraine (EM) and chronic migraine (CM) using the diffusion tensor image analysis along the perivascular space (DTI-ALPS) method. METHODS: In this cross-sectional study, patients with EM, CM, and healthy controls (HCs) were included. All participants underwent a standard brain magnetic resonance imaging (MRI) examination. Bilateral DTI-ALPS indexes were calculated for all participants and compared among EM, CM, and HC groups. Correlations between the DTI-ALPS index and clinical characteristics were analyzed. RESULTS: A total of 32 patients with EM, 24 patients with CM, and 41 age- and sex-matched HCs were included in the analysis. Significant differences were found in the right DTI-ALPS index among the three groups (p = 0.011), with CM showing significantly higher values than EM (p = 0.033) and HCs (p = 0.015). The right DTI-ALPS index of CM group was significantly higher than the left DTI-ALPS index (p = 0.005). And the headache intensity was correlated to DTI-ALPS index both in the left hemisphere (r = 0.371, p = 0.011) and in the right hemisphere (r = 0.307, p = 0.038), but there were no correlations after Bonferroni correction. CONCLUSIONS: Glymphatic system activity is shown to be increased instead of impaired during migraine chronification. The mechanism behind this observation suggests that increased glymphatic activity is more likely to be a concomitant phenomenon of altered vascular reactivity associated with migraine pathophysiology rather than a risk factor of migraine chronification.
Asunto(s)
Sistema Glinfático , Trastornos de Cefalalgia , Trastornos Migrañosos , Humanos , Sistema Glinfático/diagnóstico por imagen , Estudios Transversales , Trastornos Migrañosos/diagnóstico por imagen , CefaleaRESUMEN
BACKGROUND: Amygdala, an essential element of the limbic system, has served as an important structure in pain modulation. There is still a lack of clarity about altered cerebral perfusion of amygdala in migraine. This study aimed to investigate the perfusion variances of bilateral amygdala in episodic migraine (EM) and chronic migraine (CM) using multi-delay pseudo-continuous arterial spin-labeled magnetic resonance imaging (pCASL-MRI). METHODS: Twenty-six patients with EM, 55 patients with CM (33 CM with medication overuse headache (MOH)), and 26 age- and sex-matched healthy controls (HCs) were included. All participants underwent 3D multi-delay pCASL MR imaging to obtain cerebral perfusion data, including arrival-time-corrected cerebral blood flow (CBF) and arterial cerebral blood volume (aCBV). The CBF and aCBV values in the bilateral amygdala were compared among the three groups. Correlation analyses between cerebral perfusion parameters and clinical variables were performed. RESULTS: Compared with HC participants, patients with CM were found to have increased CBF and aCBV values in the left amygdala, as well as increased CBF values in the right amygdala (all P < 0.05). There were no significant differences of CBF and aCBV values in the bilateral amygdala between the HC and EM groups, the EM and CM groups, as well as the CM without and with MOH groups (all P > 0.05). In patients with CM, the increased perfusion parameters of bilateral amygdala were positively correlated with MIDAS score after adjustments for age, sex, and body mass index (BMI). CONCLUSION: Hyperperfusion of bilateral amygdala might provide potential hemodynamics evidence in the neurolimbic pain network of CM.
Asunto(s)
Imagen por Resonancia Magnética , Trastornos Migrañosos , Humanos , Marcadores de Spin , Imagen por Resonancia Magnética/métodos , Trastornos Migrañosos/diagnóstico por imagen , Amígdala del Cerebelo/diagnóstico por imagen , Circulación Cerebrovascular/fisiología , Dolor , Angiografía por Resonancia Magnética/métodosRESUMEN
Objectives: Magnetic susceptibility changes in brain MRI of Wilson's disease (WD) patients have been described in subcortical nuclei especially the basal ganglia. The objectives of this study were to investigate its relationship with other microstructural and functional alterations of the subcortical nuclei and the diagnostic utility of these MRI-related metrics. Methods: A total of 22 WD patients and 20 healthy controls (HCs) underwent 3.0T multimodal MRI scanning. Susceptibility, volume, diffusion microstructural indices and whole-brain functional connectivity of the putamen (PU), globus pallidus (GP), caudate nucleus (CN), and thalamus (TH) were analyzed. Receiver operating curve (ROC) was applied to evaluate the diagnostic value of the imaging data. Correlation analysis was performed to explore the connection between susceptibility change and microstructure and functional impairment of WD and screen for neuroimaging biomarkers of disease severity. Results: Wilson's disease patients demonstrated increased susceptibility in the PU, GP, and TH, and widespread atrophy and microstructural impairments in the PU, GP, CN, and TH. Functional connectivity decreased within the basal ganglia and increased between the PU and cortex. The ROC model showed higher diagnostic value of isotropic volume fraction (ISOVF, in the neurite orientation dispersion and density imaging model) compared with susceptibility. Severity of neurological symptoms was correlated with volume and ISOVF. Susceptibility was positively correlated with ISOVF in GP. Conclusion: Microstructural impairment of the basal ganglia is related to excessive metal accumulation in WD. Brain atrophy and microstructural impairments are useful neuroimaging biomarkers for the neurological impairment of WD.
RESUMEN
OBJECTIVES: To investigate the glymphatic function in patients with new daily persistent headache (NDPH) using the diffusion tensor image analysis along the perivascular space (DTI-ALPS) method. BACKGROUND: NDPH, a rare and treatment-refractory primary headache disorder, is poorly understood. There is limited evidence to suggest that headaches are associated with glymphatic dysfunction. Thus far, no studies have evaluated glymphatic function in patients with NDPH. METHODS: In this cross-sectional study conducted in the Headache Center of Beijing Tiantan Hospital, patients with NDPH and healthy controls were enrolled. All participants underwent brain magnetic resonance imaging examinations. Clinical characteristics and neuropsychological evaluation were examined in patients with NDPH. ALPS indexes for both hemispheres were measured to determine the glymphatic system function in patients with NDPH and healthy controls. RESULTS: In total, 27 patients with NDPH (14 males, 13 females; age [mean ± standard deviation (SD)]: 36.6 ± 20.6) and 33 healthy controls (15 males, 18 females; age [mean ± SD]: 36.0 ± 10.8) were included in the analysis. No significant differences between groups were observed in the left ALPS index (1.583 ± 0.182 vs. 1.586 ± 0.175, mean difference = 0.003, 95% confidence interval [CI] of difference = -0.089 to 0.096, p = 0.942), or right ALPS index (1.578 ± 0.230 vs. 1.559 ± 0.206, mean difference = -0.027, 95% CI of difference = -0.132 to 0.094, p = 0.738). Additionally, ALPS indexes were not correlated with clinical characteristics or neuropsychiatric scores. CONCLUSION: No glymphatic dysfunction was detected in patients with NDPH by means of the ALPS method. Additional studies with larger samples are needed to confirm these preliminary findings and improve the understanding of glymphatic function in NDPH.
Asunto(s)
Sistema Glinfático , Trastornos de Cefalalgia , Masculino , Femenino , Humanos , Sistema Glinfático/diagnóstico por imagen , Estudios Transversales , Cefalea , Examen NeurológicoRESUMEN
BACKGROUND AND PURPOSE: The pathogenesis of new daily persistent headache (NDPH) is not fully understood. We aim to map aberrant functional connectivity (FC) in patients with NDPH using resting-state functional magnetic resonance imaging (MRI). METHODS: Brain structural and functional MRI data were acquired from 29 patients with NDPH and 37 well-matched healthy controls (HCs) in this cross-sectional study. Region of interest (ROI) based analysis was used to compare FC between patients and HCs, with 116 brain regions in the automated anatomical labeling (AAL) atlas were defined as seeds. The correlations between aberrant FC and patients' clinical characteristics, and neuropsychological evaluation were also investigated. RESULTS: Compared with HCs, patients with NDPH showed increased FC in the left inferior occipital gyrus, right thalamus and decreased FC in right lingual gyrus, left superior occipital gyrus, right middle occipital gyrus, left inferior occipital gyrus, right inferior occipital gyrus, right fusiform gyrus, left postcentral gyrus, right postcentral gyrus, right thalamus and right superior temporal gyrus. There were no correlation between FC of these brain regions and clinical characteristics, neuropsychological evaluation after Bonferroni correction (p > 0.05/266). CONCLUSIONS: Patients with NDPH showed aberrant FC in multiple brain regions involved in perception and regulation of emotion and pain. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT05334927.
Asunto(s)
Encéfalo , Trastornos de Cefalalgia , Humanos , Estudios Transversales , Encéfalo/diagnóstico por imagen , Mapeo Encefálico/métodos , Imagen por Resonancia Magnética/métodos , CefaleaRESUMEN
OBJECTIVES: To evaluate the feasibility of 0.2-mm isotropic lenticulostriate arteries (LSAs) imaging using compressed sensing time-of-flight (CS TOF) at around 10 min on 7T, and compare the delineation and characterization of LSAs using conventional TOF and CS TOF. METHODS: Thirty healthy volunteers were examined with CS TOF and conventional TOF at 7T for around 10 min each. CS TOF was optimized to achieve 0.2-mm isotropic LSA imaging. The numbers of LSA stems and branches were counted and compared on a vascular skeleton. The length and distance were measured and compared on the most prominent branch in each hemisphere. Another patient with intracranial artery stenosis was studied to compare LSA delineation in CS TOF and digital subtraction angiography (DSA). RESULTS: The number of stems visualized with CS TOF was significantly higher than with conventional TOF in both left (p = 0.002, ICC = 0.884) and right (p < 0.001, ICC = 0.938) hemispheres. The number of branches visualized by conventional TOF was significantly lower than that by CS TOF in both left (p < 0.001, ICC = 0.893) and right (p < 0.001, ICC = 0.896) hemispheres. The lengths were statistically higher in CS TOF than in conventional TOF (left: p < 0.001, ICC = 0.868; right: p < 0.001, ICC = 0.876). CONCLUSIONS: The high-resolution CS TOF improves the delineation and characterization of LSAs over conventional TOF. High-resolution LSA imaging using CS TOF can be a promising tool for clinical research and applications in patients with neurologic diseases. KEY POINTS: ⢠0.2-mm isotropic LSA imaging for around 10 min using CS TOF at 7T is feasible. ⢠More stems and branches of LSAs with longer lengths can be delineated with CS TOF than with conventional TOF at the same scan time. ⢠High-resolution CS TOF can be a promising tool for research and applications on LSA.
Asunto(s)
Angiografía por Resonancia Magnética , Enfermedades Vasculares , Humanos , Angiografía por Resonancia Magnética/métodos , Arteria Cerebral Media , Arterias Cerebrales , Imagenología TridimensionalRESUMEN
OBJECTIVE: To explore gamma-aminobutyric acid (GABA) and glutamate/glutamine (Glx) levels in the right thalamus of patients with episodic migraine (EM) and chronic migraine (CM) and their effects on the chronification of migraine. BACKGROUND: Migraine affects approximately 1 billion people worldwide, with 2.5%-3% of people with EM progressing to CM each year. Magnetic resonance spectroscopy studies have revealed altered GABA and Glx levels in the thalamus of patients with migraine without aura, but these neurometabolic concentrations are underexplored in the thalamus of patients with CM. METHODS: In this cross-sectional study, patients with EM and CM were recruited. Mescher-Garwood point resolved spectroscopy sequence was used to acquire neurotransmitter concentrations in the right thalamus of patients with EM and CM and matched healthy controls (HCs). RESULTS: A total of 26 patients (EM, n = 11; CM, n = 15) and 16 age- and sex-matched HCs were included in the analysis. There were significantly lower GABA+/Water levels in the right thalamus of the CM group (mean ± standard deviation: 2.27 ± 0.4 [institutional units]) than that of the HC group (2.74 ± 0.4) (p = 0.026; mean difference [MD] = -0.5 [i.u.]), and lower Glx/Cr levels in the EM group (mean ± SD: 0.11 ± < 0.1) than in the HCs (0.13 ± < 0.1) and CM group (0.13 ± < 0.1) (p = 0.023, MD < -0.1, and p = 0.034, MD < -0.1, respectively). The GABA+/Glx ratio was lower in the CM group (mean ± SD: 0.38 ± 0.1) compared to the EM group (0.47 ± 0.1) (p = 0.024; MD = -0.1). The area under the curve for GABA+/Water levels in differentiating patients with CM from HCs was 0.83 (95% confidence interval 0.68, 0.98; p = 0.004). Correlation analyses within the migraine group revealed no significant correlation between metabolite concentration levels and headache characteristics after Bonferroni correction. CONCLUSION: Reduced GABA+/Water levels and imbalance of excitation/inhibition in the right thalamus may contribute to migraine chronification.
Asunto(s)
Glutamina , Trastornos Migrañosos , Humanos , Glutamina/análisis , Glutamina/metabolismo , Espectroscopía de Protones por Resonancia Magnética/métodos , Ácido Glutámico , Estudios Transversales , Trastornos Migrañosos/diagnóstico por imagen , Trastornos Migrañosos/metabolismo , Ácido gamma-Aminobutírico/análisis , Ácido gamma-Aminobutírico/metabolismo , Tálamo/diagnóstico por imagen , Tálamo/metabolismoRESUMEN
Point normal, as an intrinsic geometric property of 3D objects, not only serves conventional geometric tasks such as surface consolidation and reconstruction, but also facilitates cutting-edge learning-based techniques for shape analysis and generation. In this paper, we propose a normal refinement network, called Refine-Net, to predict accurate normals for noisy point clouds. Traditional normal estimation wisdom heavily depends on priors such as surface shapes or noise distributions, while learning-based solutions settle for single types of hand-crafted features. Differently, our network is designed to refine the initial normal of each point by extracting additional information from multiple feature representations. To this end, several feature modules are developed and incorporated into Refine-Net by a novel connection module. Besides the overall network architecture of Refine-Net, we propose a new multi-scale fitting patch selection scheme for the initial normal estimation, by absorbing geometry domain knowledge. Also, Refine-Net is a generic normal estimation framework: 1) point normals obtained from other methods can be further refined, and 2) any feature module related to the surface geometric structures can be potentially integrated into the framework. Qualitative and quantitative evaluations demonstrate the clear superiority of Refine-Net over the state-of-the-arts on both synthetic and real-scanned datasets.
RESUMEN
We propose a geometry-supporting dual convolutional neural network (GeoDualCNN) for both point cloud normal estimation and denoising. GeoDualCNN fuses the geometry domain knowledge that the underlying surface of a noisy point cloud is piecewisely smooth with the fact that a point normal is properly defined only when local surface smoothness is guaranteed. Centered around this insight, we define the homogeneous neighborhood (HoNe) which stays clear of surface discontinuities, and associate each HoNe with a point whose geometry and normal orientation is mostly consistent with that of HoNe. Thus, we not only obtain initial estimates of the point normals by performing PCA on HoNes, but also for the first time optimize these initial point normals by learning the mapping from two proposed geometric descriptors to the ground-truth point normals. GeoDualCNN consists of two parallel branches that remove noise using the first geometric descriptor (a homogeneous height map, which encodes the point-position information), while preserving surface features using the second geometric descriptor (a homogeneous normal map, which encodes the point-normal information). Such geometry-supporting network architectures enable our model to leverage previous geometry expertise and to benefit from training data. Experiments with noisy point clouds show that GeoDualCNN outperforms the state-of-the-art methods in terms of both noise-robustness and feature preservation.
RESUMEN
BACKGROUND AND PURPOSE: New daily persistent headache (NDPH) and chronic migraine (CM) are two different types of headaches that might involve vascular dysregulation. There is still a lack of clarity about altered brain perfusion in NDPH and CM. This study aimed to investigate the cerebral perfusion variances of NDPH and CM using multi-delay pseudo-continuous arterial spin-labeled magnetic resonance imaging (pCASL-MRI). METHODS: Fifteen patients with NDPH, 18 patients with CM, and 15 age- and sex-matched healthy controls (HCs) were included. All participants underwent 3D multi-delay pCASL-MRI to obtain cerebral perfusion data, including arrival-time-corrected cerebral blood flow (CBF) and arterial cerebral blood volume (aCBV). The automated anatomical labeling atlas 3 (AAL3) was used to parcellate 170 brain regions. The CBF and aCBV values in each brain region were compared among the three groups. Correlation analyses between cerebral perfusion parameters and clinical variables were performed. RESULTS: Compared with HC participants, patients with NDPH were found to have decreased CBF and aCBV values in multiple regions in the right hemisphere, including the right posterior orbital gyrus (OFCpost.R), right middle occipital gyrus (MOG.R), and ventral anterior nucleus of right thalamus (tVA.R), while patients with CM showed increased CBF and aCBV values presenting in the ventral lateral nucleus of left thalamus (tVL.L) and right thalamus (tVL.R) compared with HCs (all p < 0.05). In patients with NDPH, after age and sex adjustment, the increased aCBV values of IFGorb. R were positively correlated with GAD-7 scores; and the increased CBF and aCBV values of tVA.R were positively correlated with disease duration. CONCLUSION: The multi-delay pCASL technique can detect cerebral perfusion variation in patients with NDPH and CM. The cerebral perfusion changes may suggest different variations between NDPH and CM, which might provide hemodynamic evidence of these two types of primary headaches.
Asunto(s)
Trastornos Migrañosos , Humanos , Marcadores de Spin , Trastornos Migrañosos/diagnóstico por imagen , Imagen por Resonancia Magnética , Cefalea , Circulación CerebrovascularRESUMEN
Objective: We aimed to investigate the secular prevalence of gestational diabetes mellitus (GDM) and evaluate its adverse pregnancy outcomes among pregnant women in Hebei province, China. Methods: We analyzed the data from the monitoring information management system for pregnant women in 22 hospitals of Hebei province, China. In this study, 366,212 individuals with singleton live births from 2014 to 2021 were included, of whom 25,995 were diagnosed with gestational diabetes. We described the incidence of common complications and further analyzed the clinical characteristics in GDM patients and the relationship between GDM and adverse pregnancy outcomes. Results: The top 3 pregnancy complications in Hebei province are anemia, gestational hypertension, and GDM. The average incidence of GDM was 7.10% (25,995/366,212). The incidence rate of GDM significantly increased from 2014 to 2021 (χ2 trend = 7,140.663, P < 0.001). The top 3 regions with GDM incidence were Baoding (16.60%), Shijiazhuang (8.00%), and Tangshan (3.80%). The incidence of GDM in urban pregnant women (10.6%) is higher than that in rural areas (3.7%).The difference between the GDM and Non-GDM groups was statistically significant in terms of maternal age, gravidity, parity, education level, and incidence of pregnancy complications (gestational hypertension, heart diseases, and anemia) (P < 0.05). GDM individuals were at significantly increased risk of most assessed adverse pregnancy outcomes, including premature delivery, Cesarean delivery, uterine inertia, neonatal intensive care unit (NICU) admission, Apgar (activity-pulse-grimace-appearance-respiration) score at 1 min, and macrosomia (P < 0.05). The multivariate logistic regression analysis showed that GDM was an independent risk factor in terms of premature birth, Cesarean delivery, uterine inertia, placental abruption, NICU admission, and macrosomia. Conclusion: The risk of adverse pregnancy outcome in pregnant women with GDM is significantly increased. In order to reduce the occurrence of adverse pregnancy outcomes, effective interventions are needed.
Asunto(s)
Diabetes Gestacional , Hipertensión Inducida en el Embarazo , Enfermedades del Recién Nacido , Complicaciones del Embarazo , Nacimiento Prematuro , Inercia Uterina , Humanos , Recién Nacido , Femenino , Embarazo , Diabetes Gestacional/diagnóstico , Resultado del Embarazo/epidemiología , Macrosomía Fetal/epidemiología , Prevalencia , Placenta , Complicaciones del Embarazo/epidemiología , Aumento de Peso , Nacimiento Prematuro/epidemiología , Nacimiento Prematuro/etiología , China/epidemiologíaRESUMEN
Interacting with virtual objects via haptic feedback using the user's hand directly (virtual hand haptic interaction) provides a natural and immersive way to explore the virtual world. It remains a challenging topic to achieve 1 kHz stable virtual hand haptic simulation with no penetration amid hundreds of hand-object contacts. In this paper, we advocate decoupling the high-dimensional optimization problem of computing the graphic-hand configuration, and progressively optimizing the configuration of the graphic palm and fingers, yielding a decoupled-and-progressive optimization framework. We also introduce a method for accurate and efficient hand-object contact simulation, which constructs a virtual hand consisting of a sphere-tree model and five articulated cone frustums, and adopts a configuration-based optimization algorithm to compute the graphic-hand configuration under non-penetration contact constraints. Experimental results show both high update rate and stability for a variety of manipulation behaviors. Non-penetration between the graphic hand and complex-shaped objects can be maintained under diverse contact distributions, and even for frequent contact switches. The update rate of the haptic simulation loop exceeds 1 kHz for the whole-hand interaction with about 250 contacts.
RESUMEN
BACKGROUND: The pathogenesis of migraine chronification remains unclear. Functional and structural magnetic resonance imaging studies have shown impaired functional and structural alterations in the brains of patients with chronic migraine. The cerebellum and periaqueductal gray (PAG) play pivotal roles in the neural circuits of pain conduction and analgesia in migraine. However, few neurotransmitter metabolism studies of these migraine-associated regions have been performed. To explore the pathogenesis of migraine chronification, we measured gamma-aminobutyric acid (GABA) and glutamate/glutamine (Glx) levels in the dentate nucleus (DN) and PAG of patients with episodic and chronic migraine and healthy subjects. METHODS: Using the MEGA-PRESS sequence and a 3-Tesla magnetic resonance scanner (Signa Premier; GE Healthcare, Chicago, IL, USA), we obtained DN and PAG metabolite concentrations from patients with episodic migraine (n = 25), those with chronic migraine (n = 24), and age-matched and sex-matched healthy subjects (n = 16). Patients with chronic migraine were further divided into those with (n = 12) and without (n = 12) medication overuse headache. All scans were performed at the Beijing Tiantan Hospital, Capital Medical University. RESULTS: We found that patients with chronic migraine had significantly lower levels of GABA/water (p = 0.011) and GABA/creatine (Cr) (p = 0.026) in the DN and higher levels of Glx/water (p = 0.049) in the PAG than healthy controls. In all patients with migraine, higher GABA levels in the PAG were significantly associated with poorer sleep quality (GABA/water: r = 0.515, p = 0.017, n = 21; GABA/Cr: r = 0.522, p = 0.015, n = 21). Additionally, a lower Glx/Cr ratio in the DN may be associated with more severe migraine disability (r = -0.425, p = 0.055, n = 20), and lower GABA/water (r = -0.424, p = 0.062, n = 20) and Glx/Water (r = -0.452, p = 0.045, n = 20) may be associated with poorer sleep quality. CONCLUSIONS: Neurochemical levels in the DN and PAG may provide evidence of the pathological mechanisms of migraine chronification. Correlations between migraine characteristics and neurochemical levels revealed the pathological mechanisms of the relevant characteristics.