24 results on '"Seung Koo Lee"'
Search Results
2. Development and Testing of a Machine Learning Model Using 18F-Fluorodeoxyglucose PET/CT-Derived Metabolic Parameters to Classify Human Papillomavirus Status in Oropharyngeal Squamous Carcinoma
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Changsoo Woo, Kwan Hyeong Jo, Beomseok Sohn, Kisung Park, Hojin Cho, Won Jun Kang, Jinna Kim, and Seung-Koo Lee
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Radiology, Nuclear Medicine and imaging - Published
- 2023
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3. Qualitative and Quantitative Magnetic Resonance Imaging Phenotypes May Predict CDKN2A/B Homozygous Deletion Status in Isocitrate Dehydrogenase-Mutant Astrocytomas: A Multicenter Study
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Yae Won Park, Ki Sung Park, Ji Eun Park, Sung Soo Ahn, Inho Park, Ho Sung Kim, Jong Hee Chang, Seung-Koo Lee, and Se Hoon Kim
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Radiology, Nuclear Medicine and imaging - Published
- 2023
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4. Quality of Radiomics Research on Brain Metastasis: A Roadmap to Promote Clinical Translation
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Se Hoon Kim, Dain Kim, Eui Hyun Kim, Seok-Gu Kang, Sung Soo Ahn, Jong Hee Chang, Seung-Koo Lee, Yae Won Park, and Chae Jung Park
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Neuroimaging and Head & Neck ,Radiomics ,Brain Neoplasms ,Brain metastasis ,Machine learning ,Humans ,Original Article ,Radiology, Nuclear Medicine and imaging ,Prospective Studies ,Radiomics quality score ,Quality improvement ,Prognosis ,Biomarkers - Abstract
Objective Our study aimed to evaluate the quality of radiomics studies on brain metastases based on the radiomics quality score (RQS), Transparent Reporting of a multivariable prediction model for Individual Prognosis Or Diagnosis (TRIPOD) checklist, and the Image Biomarker Standardization Initiative (IBSI) guidelines. Materials and Methods PubMed MEDLINE, and EMBASE were searched for articles on radiomics for evaluating brain metastases, published until February 2021. Of the 572 articles, 29 relevant original research articles were included and evaluated according to the RQS, TRIPOD checklist, and IBSI guidelines. Results External validation was performed in only three studies (10.3%). The median RQS was 3.0 (range, -6 to 12), with a low basic adherence rate of 50.0%. The adherence rate was low in comparison to the “gold standard” (10.3%), stating the potential clinical utility (10.3%), performing the cut-off analysis (3.4%), reporting calibration statistics (6.9%), and providing open science and data (3.4%). None of the studies involved test-retest or phantom studies, prospective studies, or cost-effectiveness analyses. The overall rate of adherence to the TRIPOD checklist was 60.3% and low for reporting title (3.4%), blind assessment of outcome (0%), description of the handling of missing data (0%), and presentation of the full prediction model (0%). The majority of studies lacked pre-processing steps, with bias-field correction, isovoxel resampling, skull stripping, and gray-level discretization performed in only six (20.7%), nine (31.0%), four (3.8%), and four (13.8%) studies, respectively. Conclusion The overall scientific and reporting quality of radiomics studies on brain metastases published during the study period was insufficient. Radiomics studies should adhere to the RQS, TRIPOD, and IBSI guidelines to facilitate the translation of radiomics into the clinical field.
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- 2022
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5. Imaging Features of Infratentorial Desmoplastic Infantile and Non-Infantile Tumors
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Mi Jung Lee, Hyun Joo Shin, Seung Koo Lee, Myung Joon Kim, Hyun Gi Kim, and Se Hoon Kim
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lcsh:Medical physics. Medical radiology. Nuclear medicine ,Pathology ,medicine.medical_specialty ,medicine.diagnostic_test ,pediatrics ,business.industry ,lcsh:R895-920 ,Brain tumor ,Magnetic resonance imaging ,medicine.disease ,03 medical and health sciences ,0302 clinical medicine ,desmoplastic cerebral astrocytoma of infancy ,030220 oncology & carcinogenesis ,medicine ,magnetic resonance imaging ,Radiology, Nuclear Medicine and imaging ,business ,030217 neurology & neurosurgery ,brain tumor - Abstract
Purpose To describe imaging features of infratentorial desmoplastic infantile or non-infantile tumors (DIT/DNIT). Materials and Methods Four cases with infratentorial DIT/DNIT from our hospital and 5 cases from literature review were analyzed. Clinical data and MR imaging features were evaluated including location, size, shape, margin, composition, dural attachment, perilesional edema, and metastasis or multiplicity. Results The mean age was 9.2 years (range, 1–18 years). Most of the patients presented with headache or vomiting (4/9, 44.4%) and had no underlying disease (8/9, 88.9%). The major pathologic subtype was astrocytoma (6/9, 66.7%). On MR, majority of the tumors involved cerebellum and/or spinal cord (8/9, 88.9%) and the mean size of the tumors was 4.2 cm (range, 3.2–5 cm). The tumors were mainly solid (4/9, 44.4%) or mixed (4/9, 44.4%) in composition with lobulated shape (7/9, 77.8%) and well-defined margin (7/9, 77.8%). Two cases (2/7, 28.6%) showed dural attachment and all the cases had no or minimal perilesional edema (100%). Metastasis or multiplicity was frequently seen in 44.4% (4/9). Conclusion Infratentorial DIT/DNIT occurred in relatively older children and the major tumor type was astrocytoma. They also had atypical imaging features showing mainly solid or mixed in composition with frequent metastasis or multiplicity.
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- 2016
6. Structural and Resting-State Brain Alterations in Trauma-Exposed Firefighters: Preliminary Results
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Seok Jong Chung, Suhnyoung Jun, Seung Koo Lee, Sang Hoon Han, Phil Hyu Lee, Changsoo Kim, Juwhan Noh, and Yae Won Park
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firefighters ,lcsh:Medical physics. Medical radiology. Nuclear medicine ,medicine.medical_specialty ,medicine.diagnostic_test ,Resting state fMRI ,business.industry ,brain ,lcsh:R895-920 ,stress disorder ,Magnetic resonance imaging ,behavioral disciplines and activities ,Internal medicine ,medicine ,Cardiology ,magnetic resonance imaging ,Radiology, Nuclear Medicine and imaging ,business ,post-traumatic - Abstract
To analyze the altered brain regions and intrinsic brain activity patterns in trauma-exposed firefighters without posttraumatic stress disorder (PTSD).Resting-state functional MRI (rsfMRI) was performed for all subjects. Thirty-one firefighters over 40 years of age without PTSD (31 men; mean age, 49.8 ± 4.7 years) were included. Twenty-six non-traumatized healthy controls (HCs) (26 men; mean age, 65.3 ± 7.84 years) were also included. Voxel-based morphometry was performed to investigate focal differences in the brain anatomy. Seed-based functional connectivity analysis was performed to investigate differences in spontaneous brain characteristics.The mean z-scores of the Seoul Verbal Learning Test for immediate and delayed recall, Controlled Oral Word Association Test (COWAT) score for animals, and COWAT phonemic fluency were significantly lower in the firefighter group than in the HCs, indicating decreased neurocognitive function. Compared to HCs, firefighters showed reduced gray matter volume in the left superior parietal gyrus and left inferior temporal gyrus. Further, in contrast to HCs, firefighters showed alterations in rsfMRI values in multiple regions, including the fusiform gyrus and cerebellum.Structural and resting-state functional abnormalities in the brain may be useful imaging biomarkers for identifying alterations in trauma-exposed firefighters without PTSD.외상 후 스트레스 장애(posttraumatic stress disorder; 이하 PTSD)가 없는 외상에 노출된 소방관들에서 뇌 구조의 변화와 휴식기 뇌기능 변화를 연구하고자 한다.모든 피험자는 휴식기 기능 뇌자기공명영상(resting-state functional MRI; 이하 rsfMRI) 검사를 시행하였다. PTSD가 없는 40세 이상의 31명의 소방관(31명, 평균 연령, 49.8 ± 4.7세)이 포함되었다. 26명의 외상을 받지 않은 건강한 대조군(26명, 평균 연령, 65.3 ± 7.84세)도 포함되었다. Voxel-based morphometry 분석을 시행하여 뇌 해부학상의 국소적 차이를 조사하였으며, 휴식기 뇌기능의 차이를 조사하기 위해 seed-based functional connectivity analysis 분석을 시행하였다.서울언어학습결과(Seoul Verbal Learning Test)의 평균 z 값을 비교했을때 소방관은 건강한 대조군에 비해 즉각회상(immediate recall), 지연 회상(delayed recall), 통제단어연상검사(Controlled Oral Word Association Test; 이하 COWAT)의 동물(animal)과 음소(phonemic) 항목에서 점수가 유의하게 낮았으며, 신경인지 기능이 감소한 것으로 나타났다. 소방관은 좌위마루이랑(left superior parietal gyrus)과 좌하관자이랑(left inferior temporal gyrus)의 회색질 부피가 건강한 대조군에 비해 감소되어 있었다. 소방관은 방추향이랑(fusiform gyrus)과 소뇌(cerebellum) 등을 포함한 여러 부위에서 rsfMRI 값의 변화를 보였다.구조적 뇌 및 휴식 상태 기능 이상은 외상에 노출된 소방관의 변화를 확인하는 데 유용한 이미징 바이오 마커일 수 있다.
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- 2020
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7. Quality Reporting of Radiomics Analysis in Mild Cognitive Impairment and Alzheimer's Disease: A Roadmap for Moving Forward
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Sung Soo Ahn, Jinna Kim, Mina Park, So Yeon Won, Yae Won Park, and Seung Koo Lee
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medicine.medical_specialty ,Open science ,Databases, Factual ,MEDLINE ,Neuroimaging ,Hippocampus ,030218 nuclear medicine & medical imaging ,Neuroimaging and Head & Neck ,03 medical and health sciences ,0302 clinical medicine ,Physical medicine and rehabilitation ,Alzheimer Disease ,medicine ,Humans ,Dementia ,Cognitive Dysfunction ,Radiology, Nuclear Medicine and imaging ,Prospective cohort study ,Aged ,Protocol (science) ,business.industry ,Mild cognitive impairment ,Evidence-based medicine ,Alzheimer's disease ,Radiomics, Radiomics quality score ,medicine.disease ,030220 oncology & carcinogenesis ,Quality Score ,Original Article ,business - Abstract
Objective To evaluate radiomics analysis in studies on mild cognitive impairment (MCI) and Alzheimer's disease (AD) using a radiomics quality score (RQS) system to establish a roadmap for further improvement in clinical use. Materials and Methods PubMed MEDLINE and EMBASE were searched using the terms ‘cognitive impairment’ or ‘Alzheimer’ or ‘dementia’ and ‘radiomic’ or ‘texture’ or ‘radiogenomic’ for articles published until March 2020. From 258 articles, 26 relevant original research articles were selected. Two neuroradiologists assessed the quality of the methodology according to the RQS. Adherence rates for the following six key domains were evaluated: image protocol and reproducibility, feature reduction and validation, biologic/clinical utility, performance index, high level of evidence, and open science. Results The hippocampus was the most frequently analyzed (46.2%) anatomical structure. Of the 26 studies, 16 (61.5%) used an open source database (14 from Alzheimer's Disease Neuroimaging Initiative and 2 from Open Access Series of Imaging Studies). The mean RQS was 3.6 out of 36 (9.9%), and the basic adherence rate was 27.6%. Only one study (3.8%) performed external validation. The adherence rate was relatively high for reporting the imaging protocol (96.2%), multiple segmentation (76.9%), discrimination statistics (69.2%), and open science and data (65.4%) but low for conducting test-retest analysis (7.7%) and biologic correlation (3.8%). None of the studies stated potential clinical utility, conducted a phantom study, performed cut-off analysis or calibration statistics, was a prospective study, or conducted cost-effectiveness analysis, resulting in a low level of evidence. Conclusion The quality of radiomics reporting in MCI and AD studies is suboptimal. Validation is necessary using external dataset, and improvements need to be made to feature reproducibility, feature selection, clinical utility, model performance index, and pursuits of a higher level of evidence.
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- 2020
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8. Contrast-Enhanced High-Resolution Intracranial Vessel Wall MRI with Compressed Sensing: Comparison with Conventional T1 Volumetric Isotropic Turbo Spin Echo Acquisition Sequence
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Ji Hoe Heo, Hyo Suk Nam, Chae Jung Park, Jihoon Cha, Hyun Seok Choi, Seung Koo Lee, Sung Soo Ahn, and Young Dae Kim
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Adult ,Male ,Middle Cerebral Artery ,Intraclass correlation ,Image quality ,Acceleration ,Contrast Media ,Signal-To-Noise Ratio ,Neuroimaging and Head & Neck ,Lesion ,Blood vessels ,Image Processing, Computer-Assisted ,medicine ,Medical imaging ,Humans ,Radiology, Nuclear Medicine and imaging ,Vertebral Artery ,Aged ,Retrospective Studies ,medicine.diagnostic_test ,business.industry ,Isotropy ,Magnetic resonance imaging ,Middle Aged ,Fast spin echo ,Magnetic Resonance Imaging ,Carotid Arteries ,Compressed sensing ,Diagnostic imaging ,Original Article ,Female ,medicine.symptom ,Nuclear medicine ,business - Abstract
Objective Compressed sensing (CS) has gained wide interest since it accelerates MRI acquisition. We aimed to compare the 3D post-contrast T1-weighted volumetric isotropic turbo spin echo acquisition (VISTA) with CS (VISTA-CS) and without CS (VISTA-nonCS) in intracranial vessel wall MRIs (VW-MRI). Materials and methods From April 2017 to July 2018, 72 patients who underwent VW-MRI, including both VISTA-CS and VISTA-nonCS, were retrospectively enrolled. Wall and lumen volumes, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) were measured from normal and lesion sites. Two neuroradiologists independently evaluated overall image quality and degree of normal and lesion wall delineation with a four-point scale (scores ≥ 3 defined as acceptable). Results Scan coverage was increased in VISTA-CS to cover both anterior and posterior circulations with a slightly shorter scan time compared to VISTA-nonCS (approximately 7 minutes vs. 8 minutes). Wall and lumen volumes were not significantly different with VISTA-CS or VISTA-nonCS (interclass correlation coefficient = 0.964-0.997). SNR was or trended towards significantly higher values in VISTA-CS than in VISTA-nonCS. At normal sites, CNR was not significantly different between two sequences (p = 0.907), whereas VISTA-CS provided lower CNR in lesion sites compared with VISTA-nonCS (p = 0.003). Subjective wall delineation was superior with VISTA-nonCS than with VISTA-CS (p = 0.019), although overall image quality did not differ (p = 0.297). The proportions of images with acceptable quality were not significantly different between VISTA-CS (83.3-97.8%) and VISTA-nonCS (75-100%). Conclusion CS may be useful for intracranial VW-MRI as it allows for larger scan coverage with slightly shorter scan time without compromising image quality.
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- 2020
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9. Radiomics MRI Phenotyping with Machine Learning to Predict the Grade of Lower-Grade Gliomas: A Study Focused on Nonenhancing Tumors
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Se Hoon Kim, Yoon Seong Choi, Yae Won Park, Jong Hee Chang, Sung Soo Ahn, and Seung Koo Lee
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Adult ,Male ,Grade ,The Cancer Genome Atlas ,Machine learning ,computer.software_genre ,World health ,Neuroimaging and Head & Neck ,Machine Learning ,Radiomics ,Glioma ,Image Processing, Computer-Assisted ,medicine ,Humans ,Radiology, Nuclear Medicine and imaging ,Internal validation ,Retrospective Studies ,Lower grade ,Receiver operating characteristic ,Brain Neoplasms ,business.industry ,Middle Aged ,medicine.disease ,Magnetic Resonance Imaging ,ROC Curve ,Area Under Curve ,Test set ,Cohort ,Original Article ,Female ,Artificial intelligence ,Neoplasm Grading ,Lower-grade glioma ,business ,computer - Abstract
Objective To assess whether radiomics features derived from multiparametric MRI can predict the tumor grade of lower-grade gliomas (LGGs; World Health Organization grade II and grade III) and the nonenhancing LGG subgroup. Materials and methods Two-hundred four patients with LGGs from our institutional cohort were allocated to training (n = 136) and test (n = 68) sets. Postcontrast T1-weighted images, T2-weighted images, and fluid-attenuated inversion recovery images were analyzed to extract 250 radiomics features. Various machine learning classifiers were trained using the radiomics features to predict the glioma grade. The trained classifiers were internally validated on the institutional test set and externally validated on a separate cohort (n = 99) from The Cancer Genome Atlas (TCGA). Classifier performance was assessed by determining the area under the curve (AUC) from receiver operating characteristic curve analysis. An identical process was performed in the nonenhancing LGG subgroup (institutional training set, n = 73; institutional test set, n = 37; and TCGA cohort, n = 37) to predict the glioma grade. Results The performance of the best classifier was good in the internal validation set (AUC, 0.85) and fair in the external validation set (AUC, 0.72) to predict the LGG grade. For the nonenhancing LGG subgroup, the performance of the best classifier was good in the internal validation set (AUC, 0.82), but poor in the external validation set (AUC, 0.68). Conclusion Radiomics feature-based classifiers may be useful to predict LGG grades. However, radiomics classifiers may have a limited value when applied to the nonenhancing LGG subgroup in a TCGA cohort.
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- 2019
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10. Atypical Unilateral Posterior Reversible Encephalopathy Syndrome Mimicking a Middle Cerebral Artery Infarction
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Mina Park, İlkay Çamlıdağ, Yang-Je Cho, Seung Koo Lee, and OMÜ
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medicine.medical_specialty ,medicine.medical_treatment ,Infarction ,Case Report ,Neuroimaging and Head & Neck ,Diagnosis, Differential ,Occlusion ,medicine ,Humans ,Lung transplantation ,Radiology, Nuclear Medicine and imaging ,medicine.diagnostic_test ,business.industry ,Acute kidney injury ,Brain ,Infarction, Middle Cerebral Artery ,Posterior reversible encephalopathy syndrome ,Magnetic resonance imaging ,Unilateral ,Acute Kidney Injury ,Middle Aged ,medicine.disease ,Magnetic Resonance Imaging ,Posterior Leukoencephalopathy Syndrome ,Female ,Radiology ,Differential diagnosis ,Tomography, X-Ray Computed ,business ,Atypical ,Lung Transplantation - Abstract
Camlidag, Ilkay/0000-0001-6151-1312; PARK, MINA/0000-0002-2005-7560 WOS: 000361504000017 PubMed: 26356795 Posterior reversible encephalopathy syndrome (PRES) is usually a reversible clinical and radiological entity associated with typical features on brain MR or CT imaging. However, the not-so-uncommon atypical radiological presentations of the condition are also present and they may go unrecognised as they are confused with other conditions. Here, we report a very rare case of atypical, unilateral PRES in a 49-year-old uremic, post-transplant female patient who presented with seizures. Initial MRI showed high-grade occlusion of the left middle cerebral artery (MCA) and Lesions suggestive of subacute infarction in the ipsilateral frontotemporoparietal Lobe. Patient symptoms had resolved a day after the onset without any specific treatment but early follow-up CT findings suggested hemorrhagic transformation. Follow-up MRI performed 2 years Later showed complete disappearence of the lesions and persisting MCA occlusion.
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- 2015
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11. Angiographic Features of Unilateral Nonbifurcating Cervical Carotid Artery: A Case Report
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Seung Koo Lee and Na Lae Eun
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medicine.medical_specialty ,business.industry ,Carotid arteries ,External carotid artery ,Conventional angiography ,Mr angiography ,Trunk ,medicine.artery ,cardiovascular system ,medicine ,Radiology, Nuclear Medicine and imaging ,cardiovascular diseases ,Common carotid artery ,Radiology ,Internal carotid artery ,business - Abstract
Nonbifurcating cervical carotid artery is defined as a common carotid artery (CCA), in which branches of the external carotid artery (ECA) arise directly from the CCA or proximal internal carotid artery (ICA) without bifurcation, and therefore there is no proximal main trunk of the ECA (1, 2). Herein, we report a case of a nonbifurcating cervical carotid artery incidentally found during cerebral aneurismal treatment, which was evident on contrast-enhanced MR angiography (MRA) and conventional angiography.
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- 2015
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12. Diffusion Tensor Imaging: Exploring the Motor Networks and Clinical Applications
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Sung Soo Ahn and Seung Koo Lee
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Pyramidal Tracts ,Review Article ,behavioral disciplines and activities ,White matter ,Neural Pathways ,mental disorders ,medicine ,Humans ,Radiology, Nuclear Medicine and imaging ,Fiber architecture ,Brain Diseases ,medicine.diagnostic_test ,business.industry ,Motor Cortex ,Brain ,Diffusion weighted imaging ,Magnetic resonance imaging ,Human brain ,Mr imaging ,Diffusion Magnetic Resonance Imaging ,Diffusion tensor imaging ,medicine.anatomical_structure ,nervous system ,Cytoarchitecture ,Anisotropy ,Nuclear medicine ,business ,Tractography ,psychological phenomena and processes ,Biomedical engineering ,Diffusion MRI - Abstract
With the advances in diffusion magnetic resonance (MR) imaging techniques, diffusion tensor imaging (DTI) has been applied to a number of neurological conditions because DTI can demonstrate microstructures of the brain that are not assessable with conventional MR imaging. Tractography based on DTI offers gross visualization of the white matter fiber architecture in the human brain in vivo. Degradation of restrictive barriers and disruption of the cytoarchitecture result in changes in the diffusion of water molecules in various pathological conditions, and these conditions can also be assessed with DTI. Yet many factors may influence the ability to apply DTI clinically, so these techniques have to be used with a cautious hand.
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- 2011
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13. Intracranial Dural Metastasis of Ewing's Sarcoma: a Case Report
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Seung Koo Lee, Kyu Sung Lee, Jinna Kim, Woohee Jung, Dong Joon Kim, Eung Yeop Kim, and Dong Ik Kim
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Adult ,musculoskeletal diseases ,congenital, hereditary, and neonatal diseases and abnormalities ,Pathology ,medicine.medical_specialty ,Neoplasm metastasis ,Skull Neoplasms ,Central nervous system ,Case Report ,Sarcoma, Ewing ,Meninges ,otorhinolaryngologic diseases ,medicine ,Humans ,Radiology, Nuclear Medicine and imaging ,Spinal Neoplasms ,business.industry ,Ewing's sarcoma ,medicine.disease ,Magnetic Resonance Imaging ,nervous system diseases ,body regions ,medicine.anatomical_structure ,Female ,Dura Mater ,Sarcoma ,Differential diagnosis ,Tomography, X-Ray Computed ,business ,Dural metastasis ,Sarcoma, Ewing's - Abstract
Although intracranial dural metastasis of Ewing's sarcoma is a very rare finding, its imaging characteristics are similar to those of its primary form in the central nervous system. Thus, this tumor must be considered in the differential diagnosis of extra-axial dural masses.
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- 2008
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14. Measuring Fractional Anisotropy of the Corpus Callosum Using Diffusion Tensor Imaging: Mid-Sagittal versus Axial Imaging Planes
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Eung Yeop Kim, Seung Koo Lee, Hae-Jeong Park, Jinna Kim, and Donghyun Kim
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Adult ,Male ,Diffusion magnetic resonance imaging ,Corpus callosum ,Slice thickness ,Partial volume ,Statistics, Nonparametric ,Fractional anisotropy ,Healthy volunteers ,Image Processing, Computer-Assisted ,medicine ,Humans ,Radiology, Nuclear Medicine and imaging ,Analysis of Variance ,Brain Mapping ,business.industry ,Sagittal plane ,Transverse plane ,medicine.anatomical_structure ,nervous system ,Anisotropy ,Original Article ,Female ,Nuclear medicine ,business ,Diffusion MRI - Abstract
Objective: Many diffusion tensor imaging (DTI) studies of the corpus callosum (CC) have been performed with a relatively thick slice thickness in the axial plane, which may result in underestimating the fractional anisotropy (FA) of the CC due to a partial volume effect. We hypothesized that the FA of the CC can be more accurately measured by using mid-sagittal DTI. We compared the FA values of the CC between the axial and mid-sagittal DTI. Materials and Methods: Fourteen healthy volunteers underwent MRI at 3.0 T. DTI was performed in both the mid-sagittal and axial planes. One 5-mm mid-sagittal image and twenty-five 2-mm axial images were obtained for the CC. The five regions of interest (ROIs) that included the prefrontal (I), premotor and supplementary motor (II), motor (III), sensory (IV) and parietal, temporal and occipital regions (V) were drawn along the border of the CC on each sagittal FA map. The FA values obtained from each region were compared between the two sagittal maps. Results: The FA values of all the regions, except for region V, were significantly increased on the mid-sagittal imaging. The FA values in region IV were significantly underestimated on the mid-sagittal image from the axial imaging, compared with those in the regions I and V (p = 0.037 and p = 0.001, respectively). Conclusion: The FA values of the CC were significantly higher on the midsagittal DTI than those on the axial DTI in regions I-IV, and particularly in the region IV. Mid-sagittal DTI may provide more accurate FA values of the CC than can the axial DTI, and mid-sagittal DTI may be more desirable for studies that compare between patients and healthy subjects.
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- 2008
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15. Cinical Application of Iopamidol (Pamiray® 300) for Cerebral Angiography
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Jinna Kim, Sung Ho Park, Seung Koo Lee, Sang Hyun Suh, Dong Joon Kim, Eung Yeop Kim, and Dong Ik Kim
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medicine.medical_specialty ,medicine.diagnostic_test ,business.industry ,Neurological examination ,Laryngeal Edema ,Iopamidol ,Contrast medium ,Blood pressure ,Angiography ,medicine ,Radiology ,business ,Adverse effect ,Cerebral angiography ,medicine.drug - Abstract
Purpose: The aim of this study was to assess the clinical safety and efficacy of Pamiray® 300 (Iopamidol; Dongkook Pharm., Seoul, Korea) as a nonionic contrast medium for cerebral angiography. Materials and Methods: One hundred patients undergoing cerebral angiography were randomly assigned to receive Pamiray® 300 after written consent had been obtained. Patients with adverse reactions were divided into two groups. One group consisted of patients with minor adverse events such as heat sensation and pain, and the other group consisted of patients with major adverse events such as dyspnea, laryngeal edema and shock. The qualities of the radiographic images were stratified into five grades by three independent radiologists. Results: No abnormality induced by Pamiray® 300 was seen by a physical and neurological examination, blood pressure measurement, electrocardiogram, respiration rate measurement and partial fraction of arterial oxygen recording. No major and severe adverse events occurred throughout the study. Patient sex, age, disease category, underlying disease and administered contrast dosage showed no statistical significance with regards to the occurrence of adverse events. The opacification of blood vessels in all patients was 'good' or 'excellent'. Conclusion: Based on the results of this study, Pamiray® 300 is a safe, efficacious and well-tolerated contrast medium for use in cerebral angiography. Thus, Pamiray® 300 can be used as a competitive medium in cerebral angiography.
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- 2007
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16. Usefulness of ACR MRI Phantom for Quality Assurance of MRI Instruments
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Dong Gyu Na, Jung Whee Lee, Tae Hwan Lim, Kook Jin Ahn, Yong Min Chang, Chang Hyun Oh, and Seung Koo Lee
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business.industry ,Medicine ,business ,Nuclear medicine ,Quality assurance ,Imaging phantom - Published
- 2006
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17. Measurement of Fractional Anisotropy in Normal Cerebral White Matter and Brain Tumors with Diffusion Tensor Imaging
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Seung Koo Lee, Si Yeon Kim, Sang Heum Kim, Yon Kwon Ihn, and Dong Ik Kim
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White matter ,Internal capsule ,medicine.anatomical_structure ,business.industry ,Fractional anisotropy ,Caudate nucleus ,Medicine ,Effective diffusion coefficient ,business ,Anisotropy ,Nuclear medicine ,Corpus callosum ,Diffusion MRI - Abstract
Purpose: The purpose of this study was to measure the apparent diffusion coefficient (ADC) and fractional anisotropy (FA) of normal adult brain tissue and tumors, and to compare the differences. Materials and Methods: Eight normal adults and ten patients in whom intracranial tumors had been diagnosed were included. Imaging was performed using a 1.5 T MR unit and a single-shot spin-echo EPI pulse sequence (TR/TE=4024/94 msec, 128 acquisition/256 reconstruction, 23 cm FOV, 5 mm thickness, 2 mm interslice gap, 4 NSA), six different direction gradients (x, y, z, xy, yz, xz), and 2 b-values (0, 1000). Isotropic ADC (D) was obtained from seven images per slice, and fractional anisotropy (FA) was calculated from the isotropic ADC and eigenvalues of three directions. A region of interest was drawn at frontal gray and white matter, periventricular white matter, the corpus callosum, internal capsule, caudate nucleus and center of the tumor mass, and for each region, fractional anisotropy readings were obtained. Results: In normal adults, the findings were as follows: frontal gray matter: D=0.810.06, FA=0.320.03; frontal white matter: D=0.790.04, FA=0.560.09, periventricular white matter: D=0.770.02, FA=0.51 0.04; corpus callosum: D=0.790.07, FA=0.820.07; internal capsule: D=0.730.04, FA=0.770.05; caudate nucleus: D=0.760.05, FA=0.350.05. High anisotropy was demonstrated in white matter, especially in the corpus callosum and internal capsule, and the degree of anisotropy was similar in gray and deep gray matter. For most brain tumors, isotropic ADC was similar to that of white matter, but fractional anisotropy was lower. A low-grade astrocytoma showed higher isotropic ADC and lower fractional anisotropy than normal white matter, and at the center of a meningioma, fractional anisotropy was high. Conclusion: For the classification of brain tumors and determination of the extent of disease, comparison between the apparent diffusion coefficient and fractional anisotropy is useful.
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- 2002
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18. Reversal of Apparent Diffusion Coefficient (ADC) Following Transient Focal Cerebral Ischemia in Cats
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Eun-Ju Kim, Seung Koo Lee, Jae-Hwan Lee, Byung In Lee, Seung-Ik Lee, Hyun Kim, Pyeong Ho Yoon, Dong Ik Kim, Eun Kee Jeong, Jong Doo Lee, and Yong Kyu Yoon
- Subjects
medicine.medical_specialty ,CATS ,business.industry ,Tetrazolium chloride ,Ischemia ,Infarction ,medicine.disease ,body regions ,chemistry.chemical_compound ,Cerebral blood volume ,chemistry ,medicine ,Effective diffusion coefficient ,Infarct core ,cardiovascular diseases ,Tissue survival ,Radiology ,business ,Nuclear medicine - Abstract
Purpose: To determine the minimal threshold ADC ratio suggesting reversible ischemia in a temporary model of MCAO. Materials and Methods: Seven Korean cats weighing 3-3.5 kg were used as a temporary model of MCAO. The MCA was occluded for 1 hour, and diffusion-weighted images (DWI), and ADC and regional cerebral blood volume (rCBV) maps, were obtained at 1, 3, 6 and 24 hours after reperfusion using a 1.5T MR unit. The Cats were sacrificed 24 hours after imaging. Triphenyl tetrazolium chloride (TTC) staining of brain slices was performed, and DWI images and TTC-stained brain slices were compared with the naked eye. Reversible ischemia was defined as the area of high signal intensity at 1-hour DWI that normalized at follow-up DWI and in which TTC staining was normal. Using the ADC image obtained at 1 hour after reperfusion, 60 ADC ratios were obtained in the periphery of the infarct and reversible ischemia. Tissue survival showing normal TTC staining was used for final determination. The sensitivity and specificity of each ADC ratio was obtained and an ROC curve was plotted. Results: Five of seven cats showed the reversible ischemia. An area of high signal intensity was seen on DWI images obtained 1 hour after reperfusion, and this improved at follow-up imaging. The distribution of the ADC ratio in the periphery of the infarct core was 0.71-0.81, and in the periphery of reversible ischemia it was 0.79-0.93. The ADC ratio of 0.80 obtained 1 hr after reperfusion predicted the survival of the ischemic tissue with 93% sensitivity and 90% specificity. The ADC ratio of the reversible ischemia was 0.820.03 at 1 hour after reperfusion, and this was higher than that of the infarct, which was 0.740.03. Conclusion: The minimal threshold ADC ratio suggesting reversible ischemia in this temporary model of MCAO was 0.80.
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- 2002
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19. Measurement of Myocardial Perfusion with Electron Beam Tomography: Comparison with 99m Tc-MIBI Scan
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Seok Jong Yoo, Hee Cheol Kang, Kyu Ok Choe, Byung Wook Choi, Jong Doo Lee, Jin-Young Choi, Tae Joo Jeon, Bang Bu Youn, Seung Koo Lee, and Kap Bum Huh
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Moderate to severe ,medicine.diagnostic_test ,business.industry ,Perfusion scanning ,Single-photon emission computed tomography ,medicine.disease ,Electron beam tomography ,Normal volunteers ,medicine ,Myocardial infarction ,Ischemic heart ,business ,Nuclear medicine ,Perfusion - Abstract
Purpose: To compare the accuracy with which electron beam tomography (EBT) and -MIBI scanning measure myocardial perfusion valve. Materials and Methods: Twenty-two subjects [normal volunteers (n = 6), patients in whom ischemic heart disease was diagnosed (n = 5), and those in whom ischemic heart disease was suspected but who were found to be normal (n = 11)] were involved in this study. EBT was performed after bolus injection of contrast media (50 ml of Iopamiro 370 or Optiray 350, 3 ml/sec). The myocardium was divided into 16 segments according to the classification devised by the American Society of Echocardiography, and each myocardial perfusion value was calculated by post-image processing. A pharmacologic stress test was performed in all subjects except four patients with acute myocardial infarction, and myocardial perfusion reserve ratios were assessed. Single photon emission computed tomography (SPECT) was performed after the injection of 20 mCi of -MIBI. Any segments with moderate to severe photon defect on visual analysis of SPECT were identified and perfusion values determined by EBT in normal and ischemic segments were compared. Results: No difference in myocardial perfusion was found between volunteers and the suspected group. Their perfusion values were 0.710.14 ml/g/min in the resting state and 1.160.24 ml/g/min on the stress test and the myocardial perfusion reserve ratio was, therefore, 1:1.680.38. In ischemic patients, -MIBI scanning revealed a perfusion defect in 28 segments, and on EBT the measurement obtained was 0.540.19 ml/g/min. The remaining 324 perfusion segments shown by SPECT to be normal showed a perfusion value of 0.790.22 ml/g/min on EBT. Conclusion: Compared with -MIBI scanning, the measurement of myocardial perfusion by EBT provides absolute quantification of perfusion value and more detailed anatomic information.
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- 2000
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20. Enhancement Pattern of Small Hepatic Hemangioma: Findings on Multiphase Spiral CT and Dynamic MRI
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Jongmin Lee, Seung Koo Lee, Byung In Choi, Myeong-Jin Kim, Hyung Sik Yoo, and Jae-Joon Chung
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Hepatic Hemangioma ,medicine.medical_specialty ,business.industry ,Dynamic contrast-enhanced MRI ,medicine ,Enhancement pattern ,Radiology ,Spiral ct ,business - Published
- 1999
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21. Cerebral Blood Volume and Relative Perfusion Rate Mapping with Contrast Enhanced Gradient Echo Echo PlanarImaging
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Dong Ik Kim, Pyeong Jeon, Hyun Kim, Eun Kee Jeong, Yong Min Huh, Geum Joo Hwang, Seung Koo Lee, and Pyeong Ho Yoon
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medicine.medical_specialty ,business.industry ,media_common.quotation_subject ,Echo (computing) ,Nuclear magnetic resonance ,Cerebral blood volume ,Cerebral blood flow ,Perfusion rate ,medicine ,Contrast (vision) ,Radiology ,business ,Gradient echo ,media_common - Published
- 1998
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22. Mammographic and Sonographic Findings of Unilateral Breast Edema in Congestive Heart Failure: A Case Report
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Eun Kyung Kim, Seung Koo Lee, and Ki Keun Oh
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medicine.medical_specialty ,medicine.diagnostic_test ,business.industry ,medicine.disease ,Subcutaneous fat ,Increased echogenicity ,Lymphatic system ,Heart failure ,Reticular connective tissue ,medicine ,Mammography ,Radiology ,business ,Calcification ,Breast edema - Abstract
Unilateral breast edema has many causes, though among these, congestive heart failure is rare. We report mamographic and sonographic findings of unilateral breast edema due to congestive heart failure. Mammography showed diffuse increase density and skin thickening but no evidence of mass or calcification. Ultrasonography showed skin thickening and increased echogenicity in the subcutaneous fat layer, while in the dermal layer, with tubular and reticular anechoic structures sugestive of dilated lymphatics were seen . After treatment of the heart failure, resolution of the abnormalities seen on mammogram established that these were secondary findings.
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- 1997
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23. Structural and Resting-State Brain Alterations in Trauma-Exposed Firefighters: Preliminary Results
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Yae Won Park, Suhnyoung Jun, Juwhan Noh, Seok Jong Chung, Sanghoon Han, Phil Hyu Lee, Changsoo Kim, and Seung-Koo Lee
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brain ,firefighters ,magnetic resonance imaging ,stress disorder ,post-traumatic ,Medical physics. Medical radiology. Nuclear medicine ,R895-920 - Abstract
Purpose To analyze the altered brain regions and intrinsic brain activity patterns in trauma-exposed firefighters without posttraumatic stress disorder (PTSD). Materials and Methods Resting-state functional MRI (rsfMRI) was performed for all subjects. Thirty-one firefighters over 40 years of age without PTSD (31 men; mean age, 49.8 ± 4.7 years) were included. Twenty-six non-traumatized healthy controls (HCs) (26 men; mean age, 65.3 ± 7.84 years) were also included. Voxel-based morphometry was performed to investigate focal differences in the brain anatomy. Seed-based functional connectivity analysis was performed to investigate differences in spontaneous brain characteristics. Results The mean z-scores of the Seoul Verbal Learning Test for immediate and delayed recall, Controlled Oral Word Association Test (COWAT) score for animals, and COWAT phonemic fluency were significantly lower in the firefighter group than in the HCs, indicating decreased neurocognitive function. Compared to HCs, firefighters showed reduced gray matter volume in the left superior parietal gyrus and left inferior temporal gyrus. Further, in contrast to HCs, firefighters showed alterations in rsfMRI values in multiple regions, including the fusiform gyrus and cerebellum. Conclusion Structural and resting-state functional abnormalities in the brain may be useful imaging biomarkers for identifying alterations in trauma-exposed firefighters without PTSD.
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- 2020
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24. Imaging Features of Infratentorial Desmoplastic Infantile and Non-Infantile Tumors
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Hyun Gi Kim, Seung-Koo Lee, Hyun Joo Shin, Se Hoon Kim, Myung-Joon Kim, and Mi-Jung Lee
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desmoplastic cerebral astrocytoma of infancy ,magnetic resonance imaging ,pediatrics ,brain tumor ,Medical physics. Medical radiology. Nuclear medicine ,R895-920 - Abstract
Purpose To describe imaging features of infratentorial desmoplastic infantile or non-infantile tumors (DIT/DNIT). Materials and Methods Four cases with infratentorial DIT/DNIT from our hospital and 5 cases from literature review were analyzed. Clinical data and MR imaging features were evaluated including location, size, shape, margin, composition, dural attachment, perilesional edema, and metastasis or multiplicity. Results The mean age was 9.2 years (range, 1–18 years). Most of the patients presented with headache or vomiting (4/9, 44.4%) and had no underlying disease (8/9, 88.9%). The major pathologic subtype was astrocytoma (6/9, 66.7%). On MR, majority of the tumors involved cerebellum and/or spinal cord (8/9, 88.9%) and the mean size of the tumors was 4.2 cm (range, 3.2–5 cm). The tumors were mainly solid (4/9, 44.4%) or mixed (4/9, 44.4%) in composition with lobulated shape (7/9, 77.8%) and well-defined margin (7/9, 77.8%). Two cases (2/7, 28.6%) showed dural attachment and all the cases had no or minimal perilesional edema (100%). Metastasis or multiplicity was frequently seen in 44.4% (4/9). Conclusion Infratentorial DIT/DNIT occurred in relatively older children and the major tumor type was astrocytoma. They also had atypical imaging features showing mainly solid or mixed in composition with frequent metastasis or multiplicity.
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- 2016
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