Publications by authors named "Shigeki Aoki"

Article Synopsis
  • - The study explores how the brain processes stopping behaviors when faced with external signals, focusing on the pathways involved in this response inhibition.
  • - Researchers utilized neuroimaging techniques and brain stimulation to map out a four-step processing pathway that starts from the visual cortex and moves through various brain regions before reaching motor control areas.
  • - Findings highlight the crucial roles of specific areas within the insular and prefrontal cortices, revealing how these regions communicate to efficiently inhibit responses, establishing a linked circuit: V1→daINS→vpIFC/aIFC→BG/M1.
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This study included 52 Japanese older adults with Pittsburgh Sleep Quality Index (PSQI) scores > 5 and 52 healthy controls (HCs) with PSQI score ≤ 5. Diffusion-weighted imaging (DWI) and 3D T1-weighted imaging were acquired using 3T magnetic resonance imaging. The diffusion tensor image analysis along the perivascular space (DTI-ALPS) index was calculated using preprocessed DWI.

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Purpose:  The purpose of this study is to investigate the potential of deep learning (DL) techniques to enhance the image quality of low-field knee MR images, with the ultimate goal of approximating the standards of high-field knee MR imaging.

Methods: We analyzed knee MR images collected from 45 patients with knee disorders and six normal subjects using a 3T MR scanner and those collected from 25 patients with knee disorders using a 0.4T MR scanner.

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  • * A study compared 50 poor sleepers and 50 good sleepers, revealing that poor sleepers had significantly lower myelin volume in key brain regions, which correlated with decreased cognitive function and increased depression.
  • * The findings suggest that circadian clock gene expression plays a role in these differences, with certain genes linked to regional variations in myelin content and overall brain health in relation to sleep quality.
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Objective: Flow diverters (FD) are innovative treatments for wide-neck intracranial aneurysms. After-treatment verification of embolization and parent vessel patency is crucial. While evaluation using time-of-flight magnetic resonance angiography (TOF-MRA) is useful, it suffers from signal loss within the FD due to susceptibility effects.

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  • Accurate diagnosis of schizophrenia spectrum disorder is crucial for improving patient outcomes, and this paper presents a novel method using evolutionary algorithms to create effective graph neural networks for prediction.
  • The study introduces the EA-GNAS method, which not only identifies high-performance networks but also ensures the interpretability of predictions through GNNExplainer.
  • Results indicate that this new approach significantly outperforms traditional and deep learning methods in accuracy and other metrics, enhancing our understanding of brain function and aiding in the diagnosis of schizophrenia spectrum disorder.
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Background: Self-disturbance has been considered as a core symptomatology of schizophrenia and its emergence from the prodromal phase makes it a crucial target for early detection and intervention in schizophrenia. Currently, the clinical assessment of self-disturbance relies on the self-report of patients, and clinicians have no diagnostic tools in clinical practice. Identifying the neural substrate of self-disturbance would be of great clinical value by shedding light on the core dimension of schizophrenia.

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  • Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are severe, rare skin reactions primarily triggered by drugs, leading to significant health risks and complications.
  • The review suggests new diagnostic criteria to better identify these conditions and highlights recent research on how specific immune responses and genetic factors contribute to their development.
  • It also discusses current and emerging treatment options, including debates on immunosuppressive therapies and new drug developments targeting specific mechanisms involved in SJS/TEN, advocating for a more collaborative approach in medical research to improve patient care.
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Background And Objectives: Integrating large language models (LLMs) such as GPT-4 Turbo into diagnostic imaging faces a significant challenge, with current misdiagnosis rates ranging from 30-50%. This study evaluates how prompt engineering and confidence thresholds can improve diagnostic accuracy in neuroradiology.

Methods: We analyze 751 neuroradiology cases from the American Journal of Neuroradiology using GPT-4 Turbo with customized prompts to improve diagnostic precision.

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  • The study assessed the repeatability of T1 and T2* relaxation times and quantitative susceptibility (χ) values using quantitative parameter mapping (QPM) across three different 3T MRI scanners at three sites.
  • Twelve healthy volunteers underwent three separate scans at each site, and various statistical analyses were used to measure consistency and variation.
  • Results showed high intra-site repeatability for all measured values (T1, T2*, and χ) and acceptable cross-site reproducibility, suggesting QPM can reliably support multisite studies in MRI research.
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  • A new deep learning-based method for brain segmentation (DLHBS) has been developed to accurately segment T1-weighted MRI scans into 107 brain subregions and calculate their volumes.
  • The method was trained on data from 486 subjects and tested for consistency in volume measurements using scans from 11 healthy subjects across three MRI scanners.
  • Results indicated that DLHBS outperformed traditional segmentation tools like SPM and FreeSurfer in terms of both repeatability and reproducibility for multiple brain regions.
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  • Parkinson's disease (PD) is a progressive neurodegenerative disorder, and early biomarkers are needed for better diagnosis and understanding. This study focuses on analyzing the substantia nigra, an area affected in PD, using a new feature extraction method.
  • The researchers used images from 263 patients (124 PD and 139 non-PD) to test their method, which included training a model to classify differences in the substantia nigra between the two groups, achieving a sensitivity of 0.72 and specificity of 0.64.
  • Although the accuracy of the method is not yet on par with expert physicians, the study highlights the potential of using advanced tensorial feature extraction for diagnosing PD
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Objective and background This study aimed to develop a deep convolutional neural network (DCNN) model capable of generating synthetic 4D magnetic resonance angiography (MRA) from 3D time-of-flight (TOF) images, allowing estimation of temporal changes in arterial flow. TOF MRA provides static information about arterial structures through maximum intensity projection (MIP) processing, but it does not capture the dynamic information of contrast agent circulation, which is lost during MIP processing. Considering the principles of TOF, it is hypothesized that dynamic information about arterial blood flow is latent within TOF signals.

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Background: On-site computed tomography-derived fractional flow reserve (CT-FFR) is a feasible method for examining lesion-specific ischemia, and plaque analysis of coronary CT angiography (CCTA) is useful for predicting future cardiac events. However, their utility and association on a per-vessel level remain unclear.

Methods: We analyzed vessels showing 50-90 % stenosis on CCTA where planned revascularization was not performed after CCTA within 90 days.

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Brain-computer interfaces (BCI) enable direct communication between the brain and a computer or other external devices. They can extend a person's degree of freedom by either strengthening or substituting the human peripheral working capacity. Moreover, their potential clinical applications in medical fields include rehabilitation, affective computing, communication, and control.

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  • Idiosyncratic drug toxicities (IDTs) are rare but serious reactions that can arise after a drug is released, influenced by genetic factors, particularly specific HLA gene variations.
  • Recent studies using HLA-transgenic mice have helped reveal how immune responses to drugs can mimic those seen in humans, though more research is needed to understand how these reactions differ between organs like the skin and liver.
  • The review emphasizes the importance of combining insights from both animal models and molecular studies to improve understanding of HLA-mediated IDTs, aiming to develop better strategies to prevent harmful effects and guide future research.
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Specific human leukocyte antigen (HLA) polymorphisms combined with certain drug administration strongly correlate with skin eruption. Abacavir hypersensitivity (AHS), which is strongly associated with HLA-B*57:01, is one of the most representative examples. Conventionally, HLA transmits immunological signals via interactions with T cell receptors on the cell surface.

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Although increased aerobic glycolysis is common in various cancers, pancreatic ductal adenocarcinoma (PDAC) cells can survive a state of glycolysis suppression. We aimed to identify potential therapeutic targets in glycolysis-suppressed PDAC cells. By screening anticancer metabolic compounds, we identified SP-2509, an inhibitor of lysine-specific histone demethylase 1A (LSD1), which dramatically decreased the growth of PDAC PANC-1 cells and showed an anti-tumoral effect in tumor-bearing mice.

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Moyamoya disease (MMD) causes cerebral arterial stenosis and hemodynamic disturbance, the latter of which may disrupt glymphatic system activity, the waste clearance system. We evaluated 46 adult patients with MMD and 33 age- and sex-matched controls using diffusivity along the perivascular space (ALPS) measured with diffusion tensor imaging (ALPS index), which may partly reflect glymphatic system activity, and multishell diffusion MRI to generate freewater maps. Twenty-three patients were also evaluated via O-gas positron emission tomography (PET), and all patients underwent cognitive tests.

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Cognitive dysfunction, especially memory impairment, is a typical clinical feature of long-term symptoms caused by repetitive mild traumatic brain injury (rmTBI). The current study aims to investigate the relationship between regional brain atrophy and cognitive impairments in retired athletes with a long history of rmTBI. Overall, 27 retired athletes with a history of rmTBI (18 boxers, 3 kickboxers, 2 wrestlers, and 4 others; rmTBI group) and 23 age/sex-matched healthy participants (control group) were enrolled.

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Unlabelled: Several patients with cutaneous adverse drug reactions exhibit extracutaneous organ damages, and it becomes severe in a few patients resulting in death due to multiorgan failure. Understanding the sequential changes in various organs in patients with cutaneous eruption following drug administration will help understand disease onset and progression, aiding the development of prevention strategies and interventions. Therefore, we aimed to understand the effects of abacavir (ABC) on various organs in patients with ABC-induced eruptions by evaluating its effects in a mouse model.

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Background And Purpose: Glymphatic system in type 2 diabetes mellitus (T2DM) but not in the prodrome, prediabetes (Pre-DM) was investigated using diffusion tensor image analysis along the perivascular space (DTI-ALPS). Association between glymphatic system and insulin resistance of prominent characteristic in T2DM and Pre-DM between is yet elucidated. Therefore, this study delves into the interstitial fluid dynamics using the DTI-ALPS in both Pre-DM and T2DM and association with insulin resistance.

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Background: We aimed to investigate the diagnostic value of energy loss (EL) and baseline CT fractional flow reserve (CT-FFR) computed using computational fluid dynamics to predict functional progression of coronary stenosis in patients with type 2 diabetes mellitus.

Methods: This single-center prospective study included 61 patients with type 2 diabetes mellitus (mean age, 61 years ±9 [SD]; 43 men) showing 20-70 % stenosis who underwent serial coronary CT performed at 2-year interval between October 2015 and March 2020. A mesh-free simulation was performed to calculate the CT-FFR and EL.

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Pituitary tumors (PTs) represent about 10% of all intracranial tumors, and most are benign. However, some PTs exhibit continued growth despite multimodal therapies. Although temozolomide (TMZ), an alkylating chemotherapeutic agent, is a first-line medical treatment for aggressive PTs, some PTs are resistant to TMZ.

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Neuroinflammation contributes to the pathology and progression of Alzheimer's disease (AD), and it can be observed even with mild cognitive impairment (MCI), a prodromal phase of AD. Free water (FW) imaging estimates the extracellular water content and has been used to study neuroinflammation across several neurological diseases including AD. Recently, the role of gut microbiota has been implicated in the pathogenesis of AD.

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