Publications by authors named "Kyu Choi"

Objective: To prospectively evaluate the effect of accelerated deep learning-based reconstruction (Accel-DL) on improving brain magnetic resonance imaging (MRI) quality and reducing scan time compared to that in conventional MRI.

Materials And Methods: This study included 150 participants (51 male; mean age 57.3 ± 16.

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This study investigates a method for programming immune cells using a biomaterial-based system, providing an alternative to traditional cell manipulation techniques. It addresses the limitations of engineered adoptive T cell therapies, such as T cell exhaustion, by introducing a gelatin-hyaluronic acid (GH-GMA) hydrogel system. We characterized tonsil mesenchymal stem cells (TMSCs), lymphatic endothelial cells (T-LECs), stimulated T-CD8 T cells (STCs), and GH-GMA biomaterials.

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Purpose: Despite the decades of using radiation therapy (RT) for Graves' ophthalmopathy, the effects and optimal timing remain unclear. We retrospectively analyzed to evaluate the overall efficacy and response, predictive factors, and the effective timing of RT by assessing steroid requirement after RT in patients without prior surgery.

Methods And Materials: Between 2008 and 2022, we analyzed 74 patients with Graves' ophthalmopathy who received RT to both orbits.

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Iatrogenic pseudoaneurysm is a rare but potentially fatal complication of a thyroid biopsy. However, a standard management strategy has not yet been established. We aimed to evaluate the efficacy and safety of ultrasound (US)-guided thrombin injection (TI) for thyroid pseudoaneurysms.

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Article Synopsis
  • Dynamic contrast-enhanced MRI (DCE-MRI) is a promising tool for detecting blood-brain barrier issues but faces challenges like noise and imaging artifacts.
  • In a study with 306 patients, researchers used deep learning techniques to improve DCE-MRI by enhancing the signal-to-noise ratio and resolution.
  • Results showed that the enhanced DCE-MRI outperformed standard methods in image quality and diagnostic accuracy for identifying glioma grades while ensuring more reliable measurements of certain key parameters.
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Introduction: The genetic basis of Alzheimer's disease (AD) in Koreans is poorly understood.

Methods: We performed an AD genome-wide association study using whole-genome sequence data from 3540 Koreans (1583 AD cases, 1957 controls) and single-nucleotide polymorphism array data from 2978 Japanese (1336 AD cases, 1642 controls). Significant findings were evaluated by pathway enrichment and differential gene expression analysis in brain tissue from controls and AD cases with and without dementia prior to death.

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Purpose: The time-intensive nature of acquiring 3D T1-weighted MRI and analyzing brain volumetry limits quantitative evaluation of brain atrophy. We explore the feasibility and reliability of deep learning-based accelerated MRI scans for brain volumetry.

Methods: This retrospective study collected 3D T1-weighted data using 3T from 42 participants for the simulated acceleration dataset and 48 for the validation dataset.

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Background And Purpose: Idiopathic normal pressure hydrocephalus (iNPH) is reversible dementia that is underdiagnosed. The purpose of this study was to develop an automated diagnostic method for iNPH using artificial intelligence techniques with a T1-weighted MRI scan.

Materials And Methods: We quantified iNPH, Parkinson disease, Alzheimer disease, and healthy controls on T1-weighted 3D brain MRI scans using 452 scans for training and 110 scans for testing.

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  • The study focuses on understanding subependymal enhancement (SE) in high-grade glioma patients post-radiotherapy, aiming to differentiate between radiation-induced changes and actual tumor progression through MRI analysis.
  • Researchers analyzed data from 94 patients, utilizing advanced imaging techniques and statistical methods like logistic and Cox regression to evaluate the characteristics and outcomes of SE.
  • Findings indicated that specific SE features, such as IDH mutations and certain morphological traits, could predict regression versus progression of the tumors, with 38.3% of patients experiencing SE that often regressed within a few months after initial appearance.
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The importance of hydrogels in tissue engineering cannot be overemphasized due to their resemblance to the native extracellular matrix. However, natural hydrogels with satisfactory biocompatibility exhibit poor mechanical behavior, which hampers their application in stress-bearing soft tissue engineering. Here, we describe the fabrication of a double methacrylated gelatin bioink covalently linked to graphene oxide (GO) via a zero-length crosslinker, digitally light-processed (DLP) printable into 3D complex structures with high fidelity.

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  • This study introduces a new way to classify patients with a type of brain cancer called IDH-wildtype glioblastomas by looking at how much of the tumor is removed during surgery.
  • It involves 622 patients from one hospital and another 536 patients from three different hospitals, all of whom received standard cancer treatments and had tests to check their tumor characteristics.
  • The new classification model shows that younger patients with certain tumor features have a better chance of living longer after surgery, compared to older patients or those with less successful surgeries.
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Background: Alzheimer's disease (AD) is a neurodegenerative disorder influenced by age, sex, genetic factors, immune alterations, and infections. Multiple lines of evidence suggest that changes in antibody response are linked to AD pathology.

Methods: To elucidate the mechanisms underlying AD development, we investigated antibodies that target autoimmune epitopes using high-resolution epitope microarrays.

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Surface-bound molecular motors can drive the collective motion of cytoskeletal filaments in the form of nematic bands and polar flocks in reconstituted gliding assays. Although these "swarming transitions" are an emergent property of active filament collisions, they can be controlled and guided by tuning the surface chemistry or topography of the substrate. To date, the impact of surface topography on collective motion in active nematics is only partially understood, with most experimental studies focusing on the escape of a single filament from etched channels.

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Background And Purpose: The cerebral metabolic rate of oxygen (CMRO) is considered a robust marker of the infarct core in O-tracer-based PET. We aimed to delineate the infarct core in patients with acute ischemic stroke by using commonly used relative CBF (rCBF) < 30% and oxygen metabolism parameter of CMRO on CT perfusion in comparison with pretreatment DWI-derived infarct core volume.

Materials And Methods: Patients with acute ischemic stroke who met the inclusion criteria were recruited.

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Objectives: This study aimed to assess the impact of national health insurance coverage on newborn hearing screening (NHS) outcomes by analyzing hearing questionnaires from the National Infant Health Check-up Program (NIHCP) in South Korea.

Methods: This study evaluated the performance and referral rates of NHS using nationwide data from 814,875 infants enrolled in the 4-month NIHCP from January 2017 to December 2019. This period encompasses the periods before and after the National Health Insurance in South Korea began covering NHS expenses in October 2018.

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Article Synopsis
  • The study validated a regression model that predicts normative brain volumes in older adults, emphasizing the role of ethnicity as a key factor, built upon previous findings using a standard measurement tool called FreeSurfer.
  • The researchers applied this model to new brain volume estimates from a system designed for Korean populations, analyzing MRI data from 1,629 Koreans and 786 Caucasians aged 59-89.
  • Results showed that ethnicity was a significant predictor in most brain regions, and incorporating ethnicity-adjusted z-scores improved the diagnostic accuracy for Alzheimer’s disease, highlighting the model's effectiveness across different populations and tools.
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Objective: The glymphatic system is a glial-based perivascular network that promotes brain metabolic waste clearance. Glymphatic system dysfunction has been observed in both multiple sclerosis (MS) and neuromyelitis optica spectrum disorder (NMOSD), indicating the role of neuroinflammation in the glymphatic system. However, little is known about how the two diseases differently affect the human glymphatic system.

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The gut-brain axis (GBA) plays a significant role in various neurodegenerative disorders, such as Alzheimer's disease (AD), and the gut microbiome (GM) can bidirectionally communicate with the brain through the GBA. Thus, recent evidence indicates that the GM may affect the pathological features and the progression of AD in humans. The aim of our study was to elucidate the impact of probiotics on the pathological features of AD in a 5xFAD model.

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Background Blood-brain barrier (BBB) permeability change is a possible pathologic mechanism of autoimmune encephalitis. Purpose To evaluate the change in BBB permeability in patients with autoimmune encephalitis as compared with healthy controls by using dynamic contrast-enhanced (DCE) MRI and to explore its predictive value for treatment response in patients. Materials and Methods This single-center retrospective study included consecutive patients with probable or possible autoimmune encephalitis and healthy controls who underwent DCE MRI between April 2020 and May 2021.

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Purpose: People are exposed to low-dose radiation in medical diagnosis, occupational, or life circumstances, but the effect of low-dose radiation on human health is still controversial. The biological effects of radiation below 100 mGy are still unproven. In this study, we observed the effects of low-dose radiation (100 mGy) on gene expression in human coronary artery endothelial cells (HCAECs) and its effect on molecular signaling.

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Purpose: To predict hematoma growth in intracerebral hemorrhage patients by combining clinical findings with non-contrast CT imaging features analyzed through deep learning.

Methods: Three models were developed to predict hematoma expansion (HE) in 572 patients. We utilized multi-task learning for both hematoma segmentation and prediction of expansion: the Image-to-HE model processed hematoma slices, extracting features and computing a normalized DL score for HE prediction.

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Amyloid-β (Aβ) oligomers are implicated in the onset of Alzheimer's disease (AD). Herein, quinoline-derived half-curcumin-dioxaborine (Q-OB) fluorescent probe was designed for detecting Aβ oligomers by finely tailoring the hydrophobicity of the biannulate donor motifs in donor-π-acceptor structure. Q-OB shows a great sensing potency in dynamically monitoring oligomerization of Aβ during amyloid fibrillogenesis in vitro.

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Local recurrences in patients with grade 4 adult-type diffuse gliomas mostly occur within residual non-enhancing T2 hyperintensity areas after surgical resection. Unfortunately, it is challenging to distinguish non-enhancing tumors from edema in the non-enhancing T2 hyperintensity areas using conventional MRI alone. Quantitative DCE MRI parameters such as K and V convey permeability information of glioblastomas that cannot be provided by conventional MRI.

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Objective: Among cervical adenocarcinomas, well-differentiated gastric adenocarcinoma of the uterine cervix (WD-GAS), previously termed adenoma malignum (minimal deviation adenocarcinoma) is not well understood. Because of its rarity and difficulty in diagnosis, there is no standard care for WD-GAS. Thus, we conducted the first multicenter retrospective study on WD-GAS to clarify prognostic factors for long-term survival and recurrence.

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