Publications by authors named "Seung-Hong Choi"

Background: Olfactory dysfunction is a frequently encountered sensory disorder that increases with aging, assessed magnetic resonance imaging (MRI); however, reference quantitative values for associated anatomical structures have rarely been suggested. The aim of this study was to assess the parameters of the olfactory bulbs (OBs) and olfactory sulcus (OS) in Korean adults according to age, along with their olfactory function.

Methods: We retrospectively evaluated 217 consecutive patients (104 men, 113 women; mean age, 52.

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To develop a nonlinear, model-based parameter estimation method directly from incomplete measurements in - space for robust spectral analysis in highly accelerated chemical exchange saturation transfer (CEST) magnetic resonance imaging (MRI).. A CEST-specific, separable nonlinear model, which describes spectral decomposition using multi-pool Lorentzian functions (conventional magnetization transfer (MT), direct saturation of water signals (DS), amide, amine, and nuclear Overhauser effect) derived from the steady-state Bloch McConnel equation, is incorporated into a measurement model in CEST MRI.

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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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The mononuclear phagocytic system clears the circulating inorganic nanomaterials from the bloodstream, which raises concerns about the chronic toxicity of the accumulated metal species. A better understanding of the behavior of each metal after systemic injection is thus required for clinical translations. This study investigates the significance of the metal-ligand interaction on the accumulation of cerium and demonstrates that only the form in which cerium is coordinated to a multidentate chelator with a strong binding affinity does not accumulate in major organs.

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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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  • 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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Ceria-based nanoparticles are versatile in treating various inflammatory diseases, but their feasibility in clinical translation is undermined by safety concerns and a limited delivery system. Meanwhile, the idiopathic nature of inflammatory bowel disease (IBD) calls for a wider variety of therapeutics via moderation of the intestinal immune system. In this regard, the synthesis and oral formulation of iron-ceria nanoparticles (CF NPs) with enhanced nanozymic activity and lower toxicity risk than conventional ceria-based nanoparticles are reported.

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Velocity-selective (VS) magnetization preparation has shown great promise for non-contrast-enhanced (NCE) magnetic resonance angiography (MRA) with the ability to generate positive angiographic contrast directly using a single 3D acquisition. However, existing VS-MRA methods have an issue of aliased saturation around a certain velocity, known as velocity field-of-view (vFOV), which can cause undesired signal loss in arteries. This study aimed to develop a new version of the VS preparation pulse sequence that overcomes the aliased saturation problem in conventional VS preparation.

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Implantable bioelectronics has attracted significant attention in electroceuticals and clinical medicine for precise diagnosis and efficient treatment of target diseases. However, conventional rigid implantable devices face challenges such as poor tissue-device interface and unavoidable tissue damage during surgical implantation. Despite continuous efforts to utilize various soft materials to address such issues, their practical applications remain limited.

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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 According to 2021 World Health Organization criteria, adult-type diffuse gliomas include glioblastoma, isocitrate dehydrogenase (IDH)-wildtype; oligodendroglioma, IDH-mutant and 1p/19q-codeleted; and astrocytoma, IDH-mutant, even when contrast enhancement is lacking. Purpose To develop and validate simple scoring systems for predicting IDH and subsequent 1p/19q codeletion status in gliomas without contrast enhancement using standard clinical MRI sequences. Materials and Methods This retrospective study included adult-type diffuse gliomas lacking contrast at contrast-enhanced MRI from two tertiary referral hospitals between January 2012 and April 2022 with diagnoses confirmed at pathology.

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Article Synopsis
  • - MRI is great for visualizing soft tissues but has a major downside: long scan times due to how it collects signals.
  • - Reducing scan times is especially important in neuroimaging, where detailed, high-resolution images of brain structures are needed.
  • - Recent studies are exploring deep learning (DL) technology to speed up MRI scans and improve image quality while maintaining accuracy.
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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: 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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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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Little has been reported about the association between cerebral hyperperfusion syndrome (CHS) and blood-brain barrier (BBB) disruption in human. We aimed to investigate the changes in permeability after bypass surgery in cerebrovascular steno-occlusive diseases using dynamic contrast-enhanced MRI (DCE-MRI) and to demonstrate the association between CHS and BBB disruption. This retrospective study included 36 patients (21 hemispheres in 18 CHS patients and 20 hemispheres in 18 controls) who underwent combined bypass surgery for moyamoya and atherosclerotic steno-occlusive diseases.

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Distortion of echo planar imaging (EPI) can be corrected using B field maps, which can be estimated with the topup algorithm that requires two EPI images with opposite distortions. In this study, we propose a new algorithm, termed topup algorithm by single K-space (TASK), to generate two input images from a single k-space for the topup algorithm to correct EPI distortions. The centric EPI contains the opposite phase-encoding polarities in one k-space, which can be divided into two halves with opposite distortions.

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Background: To investigate the prognostic value of spatial features from whole-brain MRI using a three-dimensional (3D) convolutional neural network for adult-type diffuse gliomas.

Methods: In a retrospective, multicenter study, 1925 diffuse glioma patients were enrolled from 5 datasets: SNUH (n = 708), UPenn (n = 425), UCSF (n = 500), TCGA (n = 160), and Severance (n = 132). The SNUH and Severance datasets served as external test sets.

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We present the clinicopathological and molecular genetic characteristics of a neuroepithelial tumor (NET), EWSR1::PATZ1 fusion-positive with a literature review. This fusion has recently been discovered in rare central nervous system tumors and soft tissue sarcomas and was not included in the fifth edition of the WHO classifications. We identified this fusion in 2 NETs.

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Purpose: To develop and validate a dynamic contrast-enhanced (DCE) MRI-based radiomics model to predict epidermal growth factor receptor (EGFR) amplification in patients with glioblastoma, isocitrate dehydrogenase (IDH) wildtype.

Methods: Patients with pathologically confirmed glioblastoma, IDH wildtype, from January 2015 to December 2020, with an EGFR amplification status, were included. Patients who did not undergo DCE or conventional brain MRI were excluded.

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Article Synopsis
  • Adult-type diffuse glioma (grade 4) can spread locally into non-enhancing areas even after surgical removal of visible tumors, making early detection of progression challenging.
  • A study developed two deep learning models to predict early local progression, one using standard MRI and another incorporating a specific imaging technique called dynamic susceptibility contrast perfusion-weighted imaging (DSC-PWI).
  • The model with DSC-PWI showed an increased sensitivity for detecting local progression (80%) compared to the conventional model (40%), suggesting it could help in better planning of radiation therapy, despite the overall diagnostic performance needing improvement.
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Objective: To compare the image quality and diagnostic performance between standard turbo spin-echo MRI and accelerated MRI with deep learning (DL)-based image reconstruction for degenerative lumbar spine diseases.

Materials And Methods: Fifty patients who underwent both the standard and accelerated lumbar MRIs at a 1.5-T scanner for degenerative lumbar spine diseases were prospectively enrolled.

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