1.Assessment of Left Ventricular Function with Single Breath-Hold Magnetic Resonance Cine Imaging in Patients with Arrhythmia.
So Hyeon BAK ; Sung Mok KIM ; Sung Ji PARK ; Min Ji KIM ; Yeon Hyeon CHOE
Investigative Magnetic Resonance Imaging 2017;21(1):20-27
PURPOSE: To evaluate quantification results of single breath-hold (SBH) magnetic resonance (MR) cine imaging compared to results of conventional multiple breath-hold (MBH) technique for left ventricular (LV) function in patients with cardiac arrhythmia. MATERIALS AND METHODS: MR images of patients with arrhythmia who underwent MBH and SBH cine imaging at the same time on a 1.5T MR scanner were retrospectively reviewed. Both SBH and MBH cine imaging were performed with balanced steady state free precession. SBH scans were acquired using temporal parallel acquisition technique (TPAT). Fifty patients (65.4 ± 12.3 years, 72% men) were included. End-diastolic volume (EDV), end-systolic volume (ESV), stroke volume (SV), ejection fraction (EF), myocardial mass, and LV regional wall motion were evaluated. RESULTS: EF, myocardial mass, and regional wall motion were not significantly different between SBH and MBH acquisition techniques (all P-values > 0.05). EDV, ESV, and SV were significant difference between the two techniques. These parameters for SBH cine imaging with TPAT tended to lower than those in MBH. EF and myocardial mass of SBH cine imaging with TPAT showed good correlation with values of MBH cine imaging in Passing-Bablok regression charts and Bland-Altman plots. However, SBH imaging required significantly shorter acquisition time than MBH cine imaging (15 ± 7 sec vs. 293 ± 104 sec, P < 0.001). CONCLUSION: SBH cine imaging with TPAT permits shorter acquisition time with assessment results of global and regional LV function comparable to those with MBH cine imaging in patients with arrhythmia.
Arrhythmias, Cardiac*
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Humans
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Retrospective Studies
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Stroke Volume
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Ventricular Function, Left*
2.Validation of Deep-Learning Image Reconstruction for Low-Dose Chest Computed Tomography Scan: Emphasis on Image Quality and Noise
Joo Hee KIM ; Hyun Jung YOON ; Eunju LEE ; Injoong KIM ; Yoon Ki CHA ; So Hyeon BAK
Korean Journal of Radiology 2021;22(1):131-138
Objective:
Iterative reconstruction degrades image quality. Thus, further advances in image reconstruction are necessary to overcome some limitations of this technique in low-dose computed tomography (LDCT) scan of the chest. Deep-learning image reconstruction (DLIR) is a new method used to reduce dose while maintaining image quality. The purposes of this study was to evaluate image quality and noise of LDCT scan images reconstructed with DLIR and compare with those of images reconstructed with the adaptive statistical iterative reconstruction-Veo at a level of 30% (ASiR-V 30%).
Materials and Methods:
This retrospective study included 58 patients who underwent LDCT scan for lung cancer screening.Datasets were reconstructed with ASiR-V 30% and DLIR at medium and high levels (DLIR-M and DLIR-H, respectively). The objective image signal and noise, which represented mean attenuation value and standard deviation in Hounsfield units for the lungs, mediastinum, liver, and background air, and subjective image contrast, image noise, and conspicuity of structures were evaluated. The differences between CT scan images subjected to ASiR-V 30%, DLIR-M, and DLIR-H were evaluated.
Results:
Based on the objective analysis, the image signals did not significantly differ among ASiR-V 30%, DLIR-M, and DLIR-H (p = 0.949, 0.737, 0.366, and 0.358 in the lungs, mediastinum, liver, and background air, respectively). However, the noise was significantly lower in DLIR-M and DLIR-H than in ASiR-V 30% (all p < 0.001). DLIR had higher signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) than ASiR-V 30% (p = 0.027, < 0.001, and < 0.001 in the SNR of the lungs, mediastinum, and liver, respectively; all p < 0.001 in the CNR). According to the subjective analysis, DLIR had higher image contrast and lower image noise than ASiR-V 30% (all p < 0.001). DLIR was superior to ASiR-V 30% in identifying the pulmonary arteries and veins, trachea and bronchi, lymph nodes, and pleura and pericardium (all p < 0.001).
Conclusion
DLIR significantly reduced the image noise in chest LDCT scan images compared with ASiR-V 30% while maintaining superior image quality.
3.CT Radiomics in Thoracic Oncology: Technique and Clinical Applications
Geewon LEE ; So Hyeon BAK ; Ho Yun LEE
Nuclear Medicine and Molecular Imaging 2018;52(2):91-98
Precision medicine offers better treatment options and improved survival for cancer patients based on individual variability. As the success of precision medicine depends on robust biomarkers, the requirement for improved imaging biomarkers that reflect tumor biology has grown exponentially. Radiomics, the field of study in which high-throughput data are generated and large amounts of advanced quantitative features are extracted from medical images, has shown great potential as a source of quantitative biomarkers in the field of oncology. Radiomics provides quantitative information about the morphology, texture, and intratumoral heterogeneity of the tumor itself as well as features related to pulmonary function. Hence, radiomics data can be used to build descriptive and predictive clinical models that relate imaging characteristics to tumor biology phenotypes. In this review, we describe the workflow of CT radiomics, types of CT radiomics, and its clinical application in thoracic oncology.
Biology
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Biomarkers
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Humans
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Lung Neoplasms
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Phenotype
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Population Characteristics
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Precision Medicine
5.A Pictorial Review of Radiologic Findings of Foreign Bodies in the Thorax
Hee Soo WON ; Yoon Ki CHA ; Jeung Sook KIM ; Seo Jin JANG ; So Hyeon BAK ; Hyun Jung YOON
Journal of the Korean Radiological Society 2022;83(2):293-303
Thoracic foreign bodies (FBs) are serious and relatively frequent in emergency departments. Thoracic FBs may occur in association with aspiration, ingestion, trauma, or iatrogenic causes. Imaging plays an important role in the identification of FBs and their dimensions, structures, and locations, before the initiation of interventional treatment. To guide proper clinical management, radiologists should be aware of the radiologic presentations and the consequences of thoracic FBs. In this pictorial essay, we reviewed the optimal imaging settings to identify FBs in the thorax, classified thoracic FBs into four types according to their etiology, and reviewed the characteristic imaging features and the possible complications.
6.CT Radiomics in Thoracic Oncology: Technique and Clinical Applications
Geewon LEE ; So Hyeon BAK ; Ho Yun LEE
Nuclear Medicine and Molecular Imaging 2018;52(2):91-98
Precision medicine offers better treatment options and improved survival for cancer patients based on individual variability. As the success of precision medicine depends on robust biomarkers, the requirement for improved imaging biomarkers that reflect tumor biology has grown exponentially. Radiomics, the field of study in which high-throughput data are generated and large amounts of advanced quantitative features are extracted from medical images, has shown great potential as a source of quantitative biomarkers in the field of oncology. Radiomics provides quantitative information about the morphology, texture, and intratumoral heterogeneity of the tumor itself as well as features related to pulmonary function. Hence, radiomics data can be used to build descriptive and predictive clinical models that relate imaging characteristics to tumor biology phenotypes. In this review, we describe the workflow of CT radiomics, types of CT radiomics, and its clinical application in thoracic oncology.
7.Differentitation between Primary Central Nervous System Lymphoma and Glioblastoma: Added Value of Quantitative Analysis of CT Attenuation and Apparent Diffusion Coefficient.
Seung Choul LEE ; Won Jin MOON ; Jin Woo CHOI ; Hong Gee ROH ; So Hyeon BAK ; Jeong Geun YI ; Yoo Jeong YIM ; En Chul CHUNG
Journal of the Korean Society of Magnetic Resonance in Medicine 2012;16(3):226-235
PURPOSE: Purpose of this study was to determine if quantitative measures of CT attenuation and ADC values in combination with conventional imaging features can differentiate primary central nervous system lymphoma (PCNSL) and glioblastoma (GBM). MATERIALS AND METHODS: Twenty-six patients with histologically-proven GBM (14 men and 12 women; median age, 50 years; age range, 22 - 73 years) and 14 patients with PCNSL (11 men and 3 women; median age, 61 years; age range, 41 - 74 years) were enrolled. Maximum CT attenuation, minimum ADC, and lesion to normal parenchyma minimum ADC ratios were measured in solid tumor regions. Conventional imaging features were evaluated for the following: ill-defined margin, homogeneous enhancement pattern, degree of necrosis, extent of tumor involvement and multiplicity. The Mann-Whitney test was used to compare maximum CT attenuation and minimum ADC values for PCNSL and GBM. Fisher's exact test was used to evaluate relationships between pathologic diagnoses and imaging features. RESULTS: The CT attenuations were similar for PCNSL and GBM (37.84 +/- 6.90 HU versus 37.00 +/- 5.54 HU, p = 0.68), but minimum ADC and minimum ADC ratio were significant lower in PCNSL than in GBM (595.01 +/- 228.28 10(-6) mm2/s versus 736.52 +/- 162.05 10(-6) mm2/s; p = 0.028, 0.87 +/- 0.26 versus 1.14 +/- 0.29; p = 0.007). PCNSL showed greater homogeneous enhancement and smaller necrotic areas than GBM (p = 0.003 and p < 0.001, respectively) and was more likely to have multiple tumors than GBM (p = 0.039). When necrotic PCNSL (n = 4) and necrotic GBM (n = 24) were compared, minimum ADC and minimum ADC ratios were also significantly lower in PCNSL, but CT attenuation were not. CONCLUSION: Although CT attenuation does not provide valuable information, minimum ADC and minimum ADC ratio and some imaging features can aid the differentiation of PCNSL and GBM.
Central Nervous System
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Diffusion
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Glioblastoma
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Humans
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Lymphoma
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Male
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Necrosis
8.Word Embedding Reveals Cyfra 21-1 as a Biomarker for Chronic Obstructive Pulmonary Disease
Jeongwon HEO ; Da Hye MOON ; Yoonki HONG ; So Hyeon BAK ; Jeeyoung KIM ; Joo Hyun PARK ; Byoung-Doo OH ; Yu-Seop KIM ; Woo Jin KIM
Journal of Korean Medical Science 2021;36(35):e224-
Background:
Although patients with chronic obstructive pulmonary disease (COPD) experience high morbidity and mortality worldwide, few biomarkers are available for COPD.Here, we analyzed potential biomarkers for the diagnosis of COPD by using word embedding.
Methods:
To determine which biomarkers are likely to be associated with COPD, we selected respiratory disease-related biomarkers. Degrees of similarity between the 26 selected biomarkers and COPD were measured by word embedding. And we infer the similarity with COPD through the word embedding model trained in the large-capacity medical corpus, and search for biomarkers with high similarity among them. We used Word2Vec, Canonical Correlation Analysis, and Global Vector for word embedding. We evaluated the associations of selected biomarkers with COPD parameters in a cohort of patients with COPD.
Results:
Cytokeratin 19 fragment (Cyfra 21-1) was selected because of its high similarity and its significant correlation with the COPD phenotype. Serum Cyfra 21-1 levels were determined in patients with COPD and controls (4.3 ± 5.9 vs. 3.9 ± 3.6 ng/mL, P = 0.611). The emphysema index was significantly correlated with the serum Cyfra 21-1 level (correlation coefficient = 0.219,P = 0.015).
Conclusion
Word embedding may be used for the discovery of biomarkers for COPD and Cyfra 21-1 may be used as a biomarker for emphysema. Additional studies are needed to validate Cyfra 21-1 as a biomarker for COPD.
9.Word Embedding Reveals Cyfra 21-1 as a Biomarker for Chronic Obstructive Pulmonary Disease
Jeongwon HEO ; Da Hye MOON ; Yoonki HONG ; So Hyeon BAK ; Jeeyoung KIM ; Joo Hyun PARK ; Byoung-Doo OH ; Yu-Seop KIM ; Woo Jin KIM
Journal of Korean Medical Science 2021;36(35):e224-
Background:
Although patients with chronic obstructive pulmonary disease (COPD) experience high morbidity and mortality worldwide, few biomarkers are available for COPD.Here, we analyzed potential biomarkers for the diagnosis of COPD by using word embedding.
Methods:
To determine which biomarkers are likely to be associated with COPD, we selected respiratory disease-related biomarkers. Degrees of similarity between the 26 selected biomarkers and COPD were measured by word embedding. And we infer the similarity with COPD through the word embedding model trained in the large-capacity medical corpus, and search for biomarkers with high similarity among them. We used Word2Vec, Canonical Correlation Analysis, and Global Vector for word embedding. We evaluated the associations of selected biomarkers with COPD parameters in a cohort of patients with COPD.
Results:
Cytokeratin 19 fragment (Cyfra 21-1) was selected because of its high similarity and its significant correlation with the COPD phenotype. Serum Cyfra 21-1 levels were determined in patients with COPD and controls (4.3 ± 5.9 vs. 3.9 ± 3.6 ng/mL, P = 0.611). The emphysema index was significantly correlated with the serum Cyfra 21-1 level (correlation coefficient = 0.219,P = 0.015).
Conclusion
Word embedding may be used for the discovery of biomarkers for COPD and Cyfra 21-1 may be used as a biomarker for emphysema. Additional studies are needed to validate Cyfra 21-1 as a biomarker for COPD.
10.Effectiveness of the Invisalign Mandibular Advancement Appliance in Children with Class II Division 1 Malocclusion
So-Youn AN ; Hyeon-Jin KIM ; Ho-Uk LEE ; Sang-Ho BAK ; Hyo-Jin KANG ; Youn-Soo SHIM
Journal of Dental Hygiene Science 2023;23(4):245-254
Background:
This study aimed to determine the skeletal and dental effects in pediatric and adolescent Korean patients with ClassII Division 1 malocclusion treated using the Invisalign Mandibular Advancement (MAⓇ ) appliance.
Methods:
The study included patients aged 6 to 18 years who received orthodontic treatment with the MAⓇ appliance for Class II Division 1 malocclusion at the Department of Pediatric Dentistry, Wonkwnag University Daejeon Dental Hospital, between July 1, 2018, and December 31, 2021. The treatment group consisted of 20 patients, 10 boys and 10 girls. The control participants were also 10 boys and 10 girls. Lateral cephalometric radiographs were taken before and after treatment, and 41 measurements of skeletal and dental changes were measured and analyzed using the V-CephTM 8.0 (Osstem Implant). All analyses were performed using SPSS software (IBM SPSS for Windows, ver 26.0; IBM Corp.), and statistical significance was tested using paired and independent samples t-tests for within-group and between-group comparisons, respectively.
Results:
The patients in the treatment group showed significant decreases in ANB (A point, Nasion, B point), maxillary protrusion,maxillary anterior incisor labial inclination, and maxillary protrusion after treatment. However, when compared with the growth changes observed in the control group, only ANB and maxillary protrusion decreased, with no significant differences in SNA, SNB, and mandibular length.
Conclusion
Collectively, the results of this study confirm that the use of MAⓇ appliance in pediatric and adolescent Korean patients with Class II Division 1 malocclusion results in a reduction of anteroposterior skeletal and dental disharmony.