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1.
Nat Methods ; 20(1): 55-64, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36585454

RESUMO

Brain atlases are spatial references for integrating, processing, and analyzing brain features gathered from different individuals, sources, and scales. Here we introduce a collection of joint surface-volume atlases that chart postnatal development of the human brain in a spatiotemporally dense manner from two weeks to two years of age. Our month-specific atlases chart normative patterns and capture key traits of early brain development and are therefore conducive to identifying aberrations from normal developmental trajectories. These atlases will enhance our understanding of early structural and functional development by facilitating the mapping of diverse features of the infant brain to a common reference frame for precise multifaceted quantification of cortical and subcortical changes.


Assuntos
Encéfalo , Processamento de Imagem Assistida por Computador , Humanos , Lactente , Mapeamento Encefálico , Imageamento por Ressonância Magnética
2.
J Intensive Care Med ; : 8850666241246969, 2024 Apr 18.
Artigo em Inglês | MEDLINE | ID: mdl-38634177

RESUMO

Background: Endotracheal tube (ETT) occlusion is reported at a higher frequency among coronavirus disease-2019 (COVID-19) patients. Prior to the COVID-19 pandemic, literature examining patient and ventilator characteristics, including humidification, as etiologies of ETT occlusion yielded mixed results. Our study examines the relationship of humidification modality with ETT occlusion in COVID-19 patients undergoing invasive mechanical ventilation (IMV). Methods: We conducted a retrospective chart review of COVID-19 patients requiring IMV at a tertiary care center in New York from April 2020 to April 2021. Teleflex Neptune heated wire heated humidification (HH) and hygroscopic Intersurgical FiltaTherm and Sunmed Ballard 1500 heat and moisture exchangers (HME) were used. Episodes of ETT occlusion were recorded. Univariate and multivariable logistic regression models were used to investigate the relationship between humidification modality and the occurrence of ETT occlusion. Findings: A total of 201 eligible patients were identified. Teleflex HH was utilized in 50.2% of the population and the others Intersurgical and Sunmed HME devices. Median age was 62 years and 78.6% of patients had at least one medical comorbidity. Precisely, 24% of patients experienced an ETT occlusion after a median of 12 days. The HME group was younger (58.5 vs 64 years), predominantly male (75% vs 59.4%), and experienced more total ventilator days than the HH group (24 vs 12). Those using the studied HME devices had significantly higher odds of ETT occlusion (OR 4.4, 95% CI 1.8-10.6, P = .0011). Three patients (6.1%) experienced cardiac arrest as a consequence of their occlusion. There were no deaths directly attributed to ETT occlusion. Conclusions: The studied HME devices were significantly associated with higher odds of ETT occlusion in COVID-19 patients requiring invasive mechanical ventilation. These events are not without significant clinical consequences. Prolonged use of under-performing HME devices remains suspect in the occurrence of ETT occlusions.

3.
Blood Purif ; 53(1): 30-39, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-37918364

RESUMO

INTRODUCTION: Endotoxin is a key driver of sepsis, which frequently causes acute kidney injury (AKI). However, endotoxins may also be found in non-bacteremic critically ill patients, likely from intestinal translocation. Preclinical models show that endotoxins can directly injure the kidneys, and in COVID-19 patients, endotoxemia correlated with AKI. We sought to determine correlations between endotoxemia and kidney and hospital outcomes in a broad group of critically ill patients. METHODS: In this single-center, serial prospective study, 124 predominantly Caucasian adult patients were recruited within 48 h of admission to Stony Brook University Hospital Intensive Care Unit (ICU). Demographics, vital signs, laboratory data, and outcomes were collected. Circulating endotoxin was measured on days 1, 4, and 8 using the endotoxin activity assay (EAA). The association of EAA with outcomes was examined with EAA: (1) categorized as <0.6, ≥0.6, and nonresponders (NRs); and (2) used as a continuous variable. RESULTS: Patients with EAA ≥0.6 had a higher prevalence of proteinuria, and lower arterial oxygen saturation (SaO2) to fraction of inspired oxygen (FiO2) (SaO2/FiO2) ratio versus patients with EAA <0.6. EAA levels positively correlated with serum creatinine (sCr) levels on day 1. Patients whose EAA level stayed ≥0.6 had a slower decline in sCr compared to those whose EAA started at ≥0.6 and subsequently declined. Patients with AKI stage 1 and EAA ≥0.6 on day 1 showed slower decline in sCr compared to patients with stage 1 AKI and EAA <0.6. EAA ≥0.6 and NR patients had longer hospital stay and delayed ICU discharge versus EAA <0.6. CONCLUSIONS: High EAA levels correlated with worse kidney function and outcomes. Patients whose EAA levels fell, and those with AKI stage I and day 1 EAA <0.6 recovered more quickly compared to those with EAA ≥0.6, suggesting that removal of circulating endotoxins may be beneficial in critically ill patients.


Assuntos
Injúria Renal Aguda , Endotoxemia , Adulto , Humanos , Endotoxemia/complicações , Endotoxemia/terapia , Estudos Prospectivos , Tempo de Internação , Estado Terminal/epidemiologia , Endotoxinas , Unidades de Terapia Intensiva , Injúria Renal Aguda/epidemiologia , Rim , Oxigênio
4.
BMC Musculoskelet Disord ; 24(1): 684, 2023 Aug 29.
Artigo em Inglês | MEDLINE | ID: mdl-37644472

RESUMO

BACKGROUND: This study aimed to compare the effects of cognitive functional therapy (CFT) and movement system impairment (MSI)-based treatment on pain intensity, disability, Kinesiophobia, and gait kinetics in patients with chronic non-specific low back pain (CNSLBP). METHODS: In a single-blind randomized clinical trial, we randomly assigned 91 patients with CNSLBP into CFT (n = 45) and MSI-based treatment (n = 46) groups. An 8-week training intervention was given to both groups. The researchers measured the primary outcome, which was pain intensity (Numeric rating scale), and the secondary outcomes, including disability (Oswestry disability index), Kinesiophobia (Tampa Kinesiophobia Scale), and vertical ground reaction force (VGRF) parameters at self-selected and faster speed (Force distributor treadmill). We evaluated patients at baseline, at the end of the 8-week intervention (post-treatment), and six months after the first treatment. We used mixed-model ANOVA to evaluate the effects of the interaction between time (baseline vs. post-treatment vs. six-month follow-up) and group (CFT vs. MSI-based treatment) on each measure. RESULTS: CFT showed superiority over MSI-based treatment in reducing pain intensity (P < 0.001, Effect size (ES) = 2.41), ODI (P < 0.001, ES = 2.15), and Kinesiophobia (P < 0.001, ES = 2.47) at eight weeks. The CFT also produced greater improvement in VGRF parameters, at both self-selected (FPF[P < 0.001, ES = 3], SPF[P < 0.001, ES = 0.5], MSF[P < 0.001, ES = 0.67], WAR[P < 0.001, ES = 1.53], POR[P < 0.001, ES = 0.8]), and faster speed, FPF(P < 0.001, ES = 1.33, MSF(P < 0.001, ES = 0.57), WAR(P < 0.001, ES = 0.67), POR(P < 0.001, ES = 2.91)] than the MSI, except SPF(P < 0.001, ES = 0.0) at eight weeks. CONCLUSION: This study suggests that the CFT is associated with better results in clinical and cognitive characteristics than the MSI-based treatment for CNSLBP, and the researchers maintained the treatment effects at six-month follow-up. Also, This study achieved better improvements in gait kinetics in CFT. CTF seems to be an appropriate and applicable treatment in clinical setting. TRIAL REGISTRATION: The researchers retrospectively registered the trial 10/11/2022, at https://www.umin.ac.jp/ with identifier number (UMIN000047455).


Assuntos
Terapia Cognitivo-Comportamental , Dor Lombar , Humanos , Dor Lombar/diagnóstico , Dor Lombar/terapia , Método Simples-Cego , Marcha , Cognição
5.
Pattern Recognit ; 1432023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37425426

RESUMO

Missing scans are inevitable in longitudinal studies due to either subject dropouts or failed scans. In this paper, we propose a deep learning framework to predict missing scans from acquired scans, catering to longitudinal infant studies. Prediction of infant brain MRI is challenging owing to the rapid contrast and structural changes particularly during the first year of life. We introduce a trustworthy metamorphic generative adversarial network (MGAN) for translating infant brain MRI from one time-point to another. MGAN has three key features: (i) Image translation leveraging spatial and frequency information for detail-preserving mapping; (ii) Quality-guided learning strategy that focuses attention on challenging regions. (iii) Multi-scale hybrid loss function that improves translation of image contents. Experimental results indicate that MGAN outperforms existing GANs by accurately predicting both tissue contrasts and anatomical details.

6.
Nitric Oxide ; 115: 30-33, 2021 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-34229057

RESUMO

BACKGROUND: While inhaled nitric oxide (iNO) has revealed benefit in cardiac arrest in an animal model, no published data has yet demonstrated the impact of iNO in humans with cardiac arrest. METHODS: In this pilot study, we administered iNO, along with standard post-resuscitative care, in adults with in-hospital cardiac arrest (IHCA) following achievement of return of spontaneous circulation (ROSC) at an academic tertiary medical center. Patients receiving iNO were compared to age-matched controls with IHCA receiving standard care from an institutional registry. The primary outcome was survival to discharge; secondary outcome was favorable neurologic outcome, defined by a Glasgow Outcome Score of 4 or 5. Propensity-score (PS) matching analysis was performed between patients receiving iNO versus controls. RESULTS: Twenty adults with IHCA receiving iNO were compared to 199 controls with IHCA. Similar age, Charlson comorbidity index, and initial rhythm were noted in both groups. Patients receiving iNO had higher rates of survival to discharge compared to controls (35% vs 11%, p < 0.0001) but no difference in favorable neurologic outcome (15% vs 9%, p = 0.39) in the unmatched population. In the PS-matched analysis, patients receiving iNO had higher survival to discharge (35% vs 20%, p = 0.0344) than the control group but no difference in favorable neurologic outcome (15% vs 20%, p = 0.13) were noted between both groups. CONCLUSIONS: In this pilot study, iNO was associated with significantly higher rates of survival to discharge but not favorable neurologic outcome among patients with IHCA compared to controls. This benefit was also observed in the PS-matched analysis. A large scale randomized controlled trial comparing standard of care supplemented with iNO to standard of care alone is warranted in patients with cardiac arrest (Funded by Stony Brook University Renaissance School of Medicine, ClinicalTrials.gov number, NCT04134078).


Assuntos
Parada Cardíaca/tratamento farmacológico , Óxido Nítrico/uso terapêutico , Administração por Inalação , Idoso , Estudos de Viabilidade , Feminino , Hospitais , Humanos , Masculino , Pessoa de Meia-Idade , Óxido Nítrico/administração & dosagem , Projetos Piloto , Estudos Prospectivos
7.
Ann Surg ; 272(2): e63-e65, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32675499

RESUMO

BACKGROUND: A novel coronavirus (COVID-19) erupted in the latter part of 2019. The virus, SARS-CoV-2 can cause a range of symptoms ranging from mild through fulminant respiratory failure. Approximately 25% of hospitalized patients require admission to the intensive care unit, with the majority of those requiring mechanical ventilation. High density consolidations in the bronchial tree and in the pulmonary parenchyma have been described in the advanced phase of the disease. We noted a subset of patients who had a sudden, significant increase in peak airway, plateau and peak inspiratory pressures. Partial or complete ETT occlusion was noted to be the culprit in the majority of these patients. METHODS: With institutional IRB approval, we examined a subset of our mechanically ventilated COVID-19 patients. All of the patients were admitted to one of our COVID-19 ICUs. Each was staffed by a board certified intensivist. During multidisciplinary rounds, all arterial blood gas (ABG) results, ventilator settings and ventilator measurements are discussed and addressed. ARDSNet Protocols are employed. In patients with confirmed acute occlusion of the endotracheal tube (ETT), acute elevation in peak airway and peak inspiratory pressures are noted in conjunction with desaturation. Data was collected retrospectively and demographics, ventilatory settings and ABG results were recorded. RESULTS: Our team has observed impeded ventilation in intubated patients who are several days into the critical course. Pathologic evaluation of the removed endotracheal tube contents from one of our patients demonstrated a specimen consistent with sloughed tracheobronchial tissues and inflammatory cells in a background of dense mucin. Of 110 patients admitted to our adult COVID-19 ICUs, 28 patients required urgent exchange of their ETT. CONCLUSION: Caregivers need to be aware of this pathological finding, recognize, and to treat this aspect of the COVID-19 critical illness course, which is becoming more prevalent.


Assuntos
Brônquios/lesões , Infecções por Coronavirus/terapia , Intubação Intratraqueal/efeitos adversos , Pneumonia Viral/terapia , Respiração Artificial/efeitos adversos , Traqueia/lesões , Adulto , Betacoronavirus , COVID-19 , Feminino , Humanos , Unidades de Terapia Intensiva , Masculino , Pandemias , SARS-CoV-2
8.
Sci Rep ; 14(1): 5622, 2024 03 07.
Artigo em Inglês | MEDLINE | ID: mdl-38453991

RESUMO

The human cerebellum is engaged in a broad array of tasks related to motor coordination, cognition, language, attention, memory, and emotional regulation. A detailed cerebellar atlas can facilitate the investigation of the structural and functional organization of the cerebellum. However, existing cerebellar atlases are typically limited to a single imaging modality with insufficient characterization of tissue properties. Here, we introduce a multifaceted cerebellar atlas based on high-resolution multimodal MRI, facilitating the understanding of the neurodevelopment and neurodegeneration of the cerebellum based on cortical morphology, tissue microstructure, and intra-cerebellar and cerebello-cerebral connectivity.


Assuntos
Cerebelo , Imageamento por Ressonância Magnética , Humanos , Cerebelo/fisiologia , Imageamento por Ressonância Magnética/métodos , Idioma , Cognição/fisiologia , Atenção
9.
bioRxiv ; 2024 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-38915694

RESUMO

Recent evidence indicates that the organization of the human neocortex is underpinned by smooth spatial gradients of functional connectivity (FC). These gradients provide crucial insight into the relationship between the brain's topographic organization and the texture of human cognition. However, no studies to date have charted how intrinsic FC gradient architecture develops across the entire human lifespan. In this work, we model developmental trajectories of the three primary gradients of FC using a large, high-quality, and temporally-dense functional MRI dataset spanning from birth to 100 years of age. The gradient axes, denoted as sensorimotor-association (SA), visual-somatosensory (VS), and modulation-representation (MR), encode crucial hierarchical organizing principles of the brain in development and aging. By tracking their evolution throughout the human lifespan, we provide the first ever comprehensive low-dimensional normative reference of global FC hierarchical architecture. We observe significant age-related changes in global network features, with global markers of hierarchical organization increasing from birth to early adulthood and decreasing thereafter. During infancy and early childhood, FC organization is shaped by primary sensory processing, dense short-range connectivity, and immature association and control hierarchies. Functional differentiation of transmodal systems supported by long-range coupling drives a convergence toward adult-like FC organization during late childhood, while adolescence and early adulthood are marked by the expansion and refinement of SA and MR hierarchies. While gradient topographies remain stable during late adulthood and aging, we observe decreases in global gradient measures of FC differentiation and complexity from 30 to 100 years. Examining cortical microstructure gradients alongside our functional gradients, we observed that structure-function gradient coupling undergoes differential lifespan trajectories across multiple gradient axes.

10.
Inf Process Med Imaging ; 13939: 536-547, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37915753

RESUMO

Surface reconstruction of cortical and subcortical structures is crucial for brain morphological studies. Existing deep learning surface reconstruction methods, such as DeepCSR and Vox2Surf, learn an implicit field function for computing the isosurface, but do not consider mesh topology. In this paper, we propose a novel and efficient deep learning mesh deformation network, called MeshDeform, to reconstruct topologically correct surfaces of subcortical structures using brain MR images. MeshDeform combines features extracted from a U-Net encoder with mesh deformation blocks to predict surfaces of subcortical structures by deforming spherical mesh templates. MeshDeform is able to reconstruct in less than 10 seconds the surfaces of a left-right pair of subcortical structures with subvoxel accuracy. Reconstruction of all 17 subcortical structures takes less than one and a half minutes. By contrast, Vox2Surf takes about 20-30 minutes for all subcortical structures. Visual and quantitative evaluation on the Human Connectome Project (HCP) dataset demonstrate that MeshDeform generates accurate subcortical surfaces in limited time while preserving mesh topology.

11.
Sci Data ; 10(1): 489, 2023 07 27.
Artigo em Inglês | MEDLINE | ID: mdl-37500686

RESUMO

Brain magnetic resonance imaging (MRI) provides detailed soft tissue contrasts that are critical for disease diagnosis and neuroscience research. Higher MRI resolution typically comes at the cost of signal-to-noise ratio (SNR) and tissue contrast, particularly for more common 3 Tesla (3T) MRI scanners. At ultra-high magnetic field strength, 7 Tesla (7T) MRI allows for higher resolution with greater tissue contrast and SNR. However, the prohibitively high costs of 7T MRI scanners deter their widespread adoption in clinical and research centers. To obtain higher-quality images without 7T MRI scanners, algorithms that can synthesize 7T MR images from 3T MR images are under active development. Here, we make available a dataset of paired T1-weighted and T2-weighted MR images at 3T and 7T of 10 healthy subjects to facilitate the development and evaluation of 3T-to-7T MR image synthesis models. The quality of the dataset is assessed using image quality metrics implemented in MRIQC.


Assuntos
Encéfalo , Imageamento por Ressonância Magnética , Humanos , Algoritmos , Benchmarking , Encéfalo/diagnóstico por imagem , Imageamento por Ressonância Magnética/métodos , Razão Sinal-Ruído
12.
Med Phys ; 50(11): 6931-6942, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37751497

RESUMO

BACKGROUND: Cone-beam computed tomography (CBCT) plays a crucial role in the intensity modulated radiotherapy (IMRT) of prostate cancer. However, poor image contrast and fuzzy organ boundaries pose challenges to precise targeting for dose delivery and plan reoptimization for adaptive therapy. PURPOSE: In this work, we aim to enhance pelvic CBCT images by translating them to high-quality CT images with a particular focus on the anatomical structures important for radiotherapy. METHODS: We develop a novel dual-path learning framework, covering both global and local information, for organ-aware enhancement of the prostate, bladder and rectum. The global path learns coarse inter-modality translation at the image level. The local path learns organ-aware translation at the regional level. This dual-path learning architecture can serve as a plug-and-play module adaptable to other medical image-to-image translation frameworks. RESULTS: We evaluated the performance of the proposed method both quantitatively and qualitatively. The training dataset consists of unpaired 40 CBCT and 40 CT scans, the validation dataset consists of 5 paired CBCT-CT scans, and the testing dataset consists of 10 paired CBCT-CT scans. The peak signal-to-noise ratio (PSNR) between enhanced CBCT and reference CT images is 27.22 ± 1.79, and the structural similarity (SSIM) between enhanced CBCT and the reference CT images is 0.71 ± 0.03. We also compared our method with state-of-the-art image-to-image translation methods, where our method achieves the best performance. Moreover, the statistical analysis confirms that the improvements achieved by our method are statistically significant. CONCLUSIONS: The proposed method demonstrates its superiority in enhancing pelvic CBCT images, especially at the organ level, compared to relevant methods.


Assuntos
Neoplasias da Próstata , Tomografia Computadorizada de Feixe Cônico Espiral , Masculino , Humanos , Próstata , Neoplasias da Próstata/diagnóstico por imagem , Neoplasias da Próstata/radioterapia , Pelve , Tomografia Computadorizada por Raios X , Tomografia Computadorizada de Feixe Cônico/métodos , Planejamento da Radioterapia Assistida por Computador/métodos , Processamento de Imagem Assistida por Computador/métodos
13.
Respir Med Case Rep ; 38: 101695, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35799865

RESUMO

Volume assessment is an important, but challenging but crucial aspect of patient care. Fluid balance is affected by volume expansion, sepsis/shock states, cardiac and kidney failure and is present in the majority of patients. Similarly, in critically ill patients on diuretics, both excessive and inadequate diuresis can worsen outcomes. Chest X-ray (CXR) and auscultation are poorly predictive of volume status, while bioimpedance and blood volume monitoring have limitations at the bedside [4]. Inferior vena cava (IVC) diameter as measured by POCUS is a marker of intravascular volume that can provide a real-time assessment to guide diuresis. The Reverse Falls Protocol combines lung and IVC US to enable the clinician to visualize, in real-time, the patient's intravascular and extravascular volume and to set diuresis goals. We present a series of cases where euvolemia was achieved using the principles described by O'Hara, Chabra & Ahmad's Reverse Falls Protocol.

14.
Mach Learn Med Imaging ; 13583: 220-229, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37126478

RESUMO

Neuroimaging data harmonization has become a prerequisite in integrative data analytics for standardizing a wide variety of data collected from multiple studies and enabling interdisciplinary research. The lack of standardized image acquisition and computational procedures introduces non-biological variability and inconsistency in multi-site data, complicating downstream statistical analyses. Here, we propose a novel statistical technique to retrospectively harmonize multi-site cortical data collected longitudinally and cross-sectionally between birth and 100 years. We demonstrate that our method can effectively eliminate non-biological disparities from cortical thickness and myelination measurements, while preserving biological variation across the entire lifespan. Our harmonization method will foster large-scale population studies by providing comparable data required for investigating developmental and aging processes.

15.
Med Image Anal ; 81: 102548, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-35917693

RESUMO

In this paper, we present a robust reconstruction scheme for diffusion MRI (dMRI) data acquired using slice-interleaved diffusion encoding (SIDE). When combined with SIDE undersampling and simultaneous multi-slice (SMS) imaging, our reconstruction strategy is capable of significantly reducing the amount of data that needs to be acquired, enabling high-speed diffusion imaging for pediatric, elderly, and claustrophobic individuals. In contrast to the conventional approach of acquiring a full diffusion-weighted (DW) volume per diffusion wavevector, SIDE acquires in each repetition time (TR) a volume that consists of interleaved slice groups, each group corresponding to a different diffusion wavevector. This strategy allows SIDE to rapidly acquire data covering a large number of wavevectors within a short period of time. The proposed reconstruction method uses a diffusion spectrum model and multi-dimensional total variation to recover full DW images from DW volumes that are slice-undersampled due to unacquired SIDE volumes. We formulate an inverse problem that can be solved efficiently using the alternating direction method of multipliers (ADMM). Experiment results demonstrate that DW images can be reconstructed with high fidelity even when the acquisition is accelerated by 25 folds.


Assuntos
Encéfalo , Imagem de Difusão por Ressonância Magnética , Idoso , Encéfalo/diagnóstico por imagem , Encéfalo/patologia , Criança , Imagem de Difusão por Ressonância Magnética/métodos , Humanos , Processamento de Imagem Assistida por Computador/métodos , Imageamento por Ressonância Magnética
16.
IEEE Trans Med Imaging ; 41(5): 1219-1229, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-34932474

RESUMO

Deformable registration is fundamental to longitudinal and population-based image analyses. However, it is challenging to precisely align longitudinal infant brain MR images of the same subject, as well as cross-sectional infant brain MR images of different subjects, due to fast brain development during infancy. In this paper, we propose a recurrently usable deep neural network for the registration of infant brain MR images. There are three main highlights of our proposed method. (i) We use brain tissue segmentation maps for registration, instead of intensity images, to tackle the issue of rapid contrast changes of brain tissues during the first year of life. (ii) A single registration network is trained in a one-shot manner, and then recurrently applied in inference for multiple times, such that the complex deformation field can be recovered incrementally. (iii) We also propose both the adaptive smoothing layer and the tissue-aware anti-folding constraint into the registration network to ensure the physiological plausibility of estimated deformations without degrading the registration accuracy. Experimental results, in comparison to the state-of-the-art registration methods, indicate that our proposed method achieves the highest registration accuracy while still preserving the smoothness of the deformation field. The implementation of our proposed registration network is available online https://github.com/Barnonewdm/ACTA-Reg-Net.


Assuntos
Encéfalo , Processamento de Imagem Assistida por Computador , Algoritmos , Encéfalo/diagnóstico por imagem , Estudos Transversais , Humanos , Processamento de Imagem Assistida por Computador/métodos , Lactente , Imageamento por Ressonância Magnética , Redes Neurais de Computação
17.
Artigo em Inglês | MEDLINE | ID: mdl-36200667

RESUMO

A central goal in systems neuroscience is to parcellate the brain into discrete units that are neurobiologically coherent. Here, we propose a strategy for consistent whole-brain parcellation of white matter (WM) and gray matter (GM) in individuals. We parcellate the brain into coherent parcels using non-negative matrix factorization based on voxel annotation using fiber clusters. Tractography is performed using an algorithm that mitigates gyral bias, allowing full gyral and sulcal coverage for reliable parcellation of the cortical ribbon. Experimental results indicate that parcellation using our approach is highly reproducible with 100% test-retest parcel identification rate and is highly consistent with significantly lower inter-subject variability than FreeSurfer parcellation. This implies that reproducible parcellation can be obtained for subject-specific investigation of brain structure and function.

18.
Artigo em Inglês | MEDLINE | ID: mdl-35403173

RESUMO

Human brain templates are a basis for comparison of brain features across individuals. They should ideally capture an atomical details at both coarse and fine scales to facilitate comparison at varying granularity. Brain template construction typically involves spatial normalization and image fusion. While significant efforts have been dedicated to improving brain templates with sophisticated spatial normalization algorithms, image fusion is typically carried out using intensity-based averaging, causing blurring of anatomical structures. Here, we present an image fusion method that exploits cortical surfaces as guidance to help preserve details in brain templates. Our method encodes cortical boundary information given by a cortical surface mesh in a signed distance function (SDF) map. We use the SDF map to help determine localized contributions of the individual images, especially at cortical boundaries, in image fusion. Experimental results demonstrate that our method significantly improves the preservation of fine gyral and sulcal details, resulting in detailed brain templates with good surface-volume agreement.

19.
Artigo em Inglês | MEDLINE | ID: mdl-35939282

RESUMO

Most existing diffusion tractography algorithms are affected by gyral bias, causing the termination of streamlines at gyral crowns instead of sulcal banks. In this paper, we propose a tractography technique, called active cortex tractography (ACT), to overcome gyral bias by enabling fiber streamlines to curve naturally into the cortex. We show that the cortex can play an active role in cortical tractography by providing anatomical information to overcome orientation ambiguities as the streamlines enter the superficial white matter in gyral blades and approach the cortex. This is achieved by devising a direction scouting mechanism that takes into account the white matter surface normal vectors. The scouting mechanism allows probing of directions further in space to prepare the streamlines to turn at appropriate angles. The surface normal vectors guide the streamlines to turn into the cortex, perpendicular to the white-gray matter interface. Evaluation using synthetic, macaque and human data with different streamline seeding schemes demonstrates that ACT improves cortical tractography.

20.
Med Image Comput Comput Assist Interv ; 12966: 644-653, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-36222819

RESUMO

Surface reconstruction from volumetric T1-weighted and T2-weighted images is a time-consuming multi-step process that often involves careful parameter fine-tuning, hindering a more wide-spread utilization of surface-based analysis particularly in large-scale studies. In this work, we propose a fast surface reconstruction method that is based on directly learning a continuous-valued signed distance function (SDF) as implicit surface representation. This continuous representation implicitly encodes the boundary of the surface as the zero isosurface. Given the predicted SDF, the target 3D surface is reconstructed by applying the marching cubes algorithm. Our implicit reconstruction method concurrently predicts the surfaces of the brain parenchyma, the white matter and pial surfaces, the subcortical structures, and the ventricles. Evaluation based on data from the Human Connectome Project indicates that surface reconstruction of a total of 22 cortical and subcortical structures can be completed in less than 20 min.

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