Radiomics Analysis of Gray-Scale Ultrasonographic Images of Papillary Thyroid Carcinoma > 1 cm: Potential Biomarker for the Prediction of Lymph Node Metastasis

Hyun Jung Chung,Kyunghwa Han,Eunjung Lee,Jung Hyun Yoon,Vivian Youngjean Park,Minah Lee,Eun Cho,Jin Young Kwak 대한영상의학회 2023 대한영상의학회지 Vol.84 No.1

Purpose This study aimed to investigate radiomics analysis of ultrasonographic images to develop a potential biomarker for predicting lymph node metastasis in papillary thyroid carcinoma (PTC) patients. Materials and Methods This study included 431 PTC patients from August 2013 to May 2014 and classified them into the training and validation sets. A total of 730 radiomics features, including texture matrices of gray-level co-occurrence matrix and gray-level run-length matrix and single-level discrete two-dimensional wavelet transform and other functions, were obtained. The least absolute shrinkage and selection operator method was used for selecting the most predictive features in the training data set. Results Lymph node metastasis was associated with the radiomics score (p < 0.001). It was also associated with other clinical variables such as young age (p = 0.007) and large tumor size (p = 0.007). The area under the receiver operating characteristic curve was 0.687 (95% confidence interval: 0.616– 0.759) for the training set and 0.650 (95% confidence interval: 0.575–0.726) for the validation set. Conclusion This study showed the potential of ultrasonography-based radiomics to predict cervical lymph node metastasis in patients with PTC; thus, ultrasonography-based radiomics can act as a biomarker for PTC.

Follow-Up Intervals for Breast Imaging Reporting and Data System Category 3 Lesions on Screening Ultrasound in Screening and Tertiary Referral Centers

Huh Sun,Suh Hee Jung,Kim Eun-Kyung,Kim Min Jung,Yoon Jung Hyun,Park Vivian Youngjean,Moon Hee Jung 대한영상의학회 2020 Korean Journal of Radiology Vol.21 No.9

Objective: To assess the appropriate follow-up interval, and rate and timepoint of cancer detection in women with Breast Imaging Reporting and Data System (BI-RADS) 3 lesions on screening ultrasonography (US) according to the type of institution. Materials and Methods: A total of 1451 asymptomatic women who had negative or benign findings on screening mammogram, BI-RADS 3 assessment on screening US, and at least 6 months of follow-up were included. The median follow-up interval was 30.8 months (range, 6.8–52.9 months). The cancer detection rate, cancer detection timepoint, risk factors, and clinicopathological characteristics were compared between the screening and tertiary centers. Nominal variables were compared using the chisquare or Fisher’s exact test and continuous variables were compared using the independent t test or Mann-Whitney U test. Results: In 1451 women, 19 cancers (1.3%) were detected; two (0.1%) were diagnosed at 6 months and 17 (1.2%) were diagnosed after 12.3 months. The malignancy rates were both 1.3% in the screening (9 of 699) and tertiary (10 of 752) centers. In the screening center, all nine cancers were invasive cancers and diagnosed after 12.3 months. In the tertiary center, two were ductal carcinomas in situ and eight were invasive cancers. Two of the invasive cancers were diagnosed at 6 months and the remaining eight cancers newly developed after 13.1 months. Conclusion: One-year follow-up rather than 6-month follow-up may be suitable for BI-RADS 3 lesions on screening US found in screening centers. However, more caution is needed regarding similar findings in tertiary centers where 6-month follow-up may be more appropriate.

Unenhanced Breast MRI With Diffusion-Weighted Imaging for Breast Cancer Detection: Effects of Training on Performance and Agreement of Subspecialty Radiologists

Kim Yeon Soo,Lee Su Hyun,Kim Soo-Yeon,Kim Eun Sil,Park Ah Reum,Chang Jung Min,Park Vivian Youngjean,Yoon Jung Hyun,Kang Bong Joo,Yun Bo La,Kim Tae Hee,Ko Eun Sook,Chu A Jung,Kim Jin You,Youn Inyoung,C 대한영상의학회 2024 Korean Journal of Radiology Vol.25 No.1

Objective: To investigate whether reader training improves the performance and agreement of radiologists in interpreting unenhanced breast magnetic resonance imaging (MRI) scans using diffusion-weighted imaging (DWI). Materials and Methods: A study of 96 breasts (35 cancers, 24 benign, and 37 negative) in 48 asymptomatic women was performed between June 2019 and October 2020. High-resolution DWI with b-values of 0, 800, and 1200 sec/mm2 was performed using a 3.0-T system. Sixteen breast radiologists independently reviewed the DWI, apparent diffusion coefficient maps, and T1-weighted MRI scans and recorded the Breast Imaging Reporting and Data System (BI-RADS) category for each breast. After a 2-h training session and a 5-month washout period, they re-evaluated the BI-RADS categories. A BI-RADS category of 4 (lesions with at least two suspicious criteria) or 5 (more than two suspicious criteria) was considered positive. The per-breast diagnostic performance of each reader was compared between the first and second reviews. Inter-reader agreement was evaluated using a multi-rater κ analysis and intraclass correlation coefficient (ICC). Results: Before training, the mean sensitivity, specificity, and accuracy of the 16 readers were 70.7% (95% confidence interval [CI]: 59.4–79.9), 90.8% (95% CI: 85.6–94.2), and 83.5% (95% CI: 78.6–87.4), respectively. After training, significant improvements in specificity (95.2%; 95% CI: 90.8–97.5; P = 0.001) and accuracy (85.9%; 95% CI: 80.9–89.8; P = 0.01) were observed, but no difference in sensitivity (69.8%; 95% CI: 58.1–79.4; P = 0.58) was observed. Regarding inter-diffusionreader agreement, the κ values were 0.57 (95% CI: 0.52–0.63) before training and 0.68 (95% CI: 0.62–0.74) after training, with a difference of 0.11 (95% CI: 0.02–0.18; P = 0.01). The ICC was 0.73 (95% CI: 0.69–0.74) before training and 0.79 (95% CI: 0.76–0.80) after training (P = 0.002). Conclusion: Brief reader training improved the performance and agreement of interpretations by breast radiologists using unenhanced MRI with DWI.

Survival Rates of Breast Cancer Patients Aged 40 to 49 Years according to Detection Modality in Korea: Screening Ultrasound versus Mammography

Won So Yeon,Park Hyung Seok,Kim Eun-Kyung,Kim Seung Il,Moon Hee Jung,Yoon Jung Hyun,Park Vivian Youngjean,Park Seho,Kim Min Jung,Cho Young Up,Park Byeong-Woo 대한영상의학회 2021 Korean Journal of Radiology Vol.22 No.2

Objective: The aim of this study was to compare the survival rates of Korean females aged 40 to 49 years with breast cancer detected by supplemental screening ultrasound (US) or screening mammography alone. Materials and Methods: This single-institution retrospective study included 240 patients with breast cancer (mean age, 45.1 ± 2.8 years) detected by US or mammography who had undergone breast surgery between 2003 and 2008. Medical records were reviewed for clinicopathologic characteristics and detection methods. Disease-free survival (DFS) and overall survival (OS) were compared between patients with breast cancer in the US and mammography groups using the log-rank test. Multivariable cox regression analysis was used to identify independent variables associated with DFS and OS. Results: Among the 240 cases of breast cancer, 43 were detected by supplemental screening US and 197 by screening mammography (mean follow-up: 7.4 years, 93.3% with dense breasts). There were 19 recurrences and 16 deaths, all occurring in the mammography group. While the US group did not differ from the mammography group in tumor stage, the patients in this group were more likely to undergo breast-conserving surgery and radiation therapy than the mammography group. The US group also showed better DFS (p = 0.016); however, OS did not differ between the two groups (p = 0.058). In the multivariable analysis, the US group showed a lower risk of recurrence (hazard ratio, 0.097; 95% confidence interval, 0.001–0.705) compared to the mammography group. Conclusion: Our study found that Korean females aged 40–49 years with US-detected breast cancer showed better DFS than those with mammography-detected breast cancer. However, there were no statistically significant differences in OS.

Feasibility of Charcoal Tattooing of Cytology-Proven Metastatic Axillary Lymph Node at Diagnosis and Sentinel Lymph Node Biopsy after Neoadjuvant Chemotherapy in Breast Cancer Patients

Park, Seho,Koo, Ja Seung,Kim, Gun Min,Sohn, Joohyuk,Kim, Seung Il,Cho, Young Up,Park, Byeong-Woo,Park, Vivian Youngjean,Yoon, Jung Hyun,Moon, Hee Jung,Kim, Min Jung,Kim, Eun-Kyung Korean Cancer Association 2018 Cancer Research and Treatment Vol.50 No.3

<P><B>Purpose</B></P><P>Sentinel lymph node biopsy (SLNB) can be performed when node-positive disease is converted to node-negative status after neoadjuvant chemotherapy (NCT). Tattooing nodes might improve accuracy but supportive data are limited. This study aimed to investigate the feasibility of charcoal tattooing metastatic axillary lymph node (ALN) at presentation followed by SLNB after NCT in breast cancers.</P><P><B>Materials and Methods</B></P><P>Twenty patientswith cytology-proven node metastases prospectively underwent charcoal tattooing at diagnosis. SLNB using dual tracers and axillary surgery after NCT were then performed. The detection rate of tattooed node and diagnostic performance of SLNB were analyzed.</P><P><B>Results</B></P><P>All patients underwent charcoal tattooingwithout significant morbidity. Sentinel and tattooed nodes could be detected during surgery after NCT. Nodal pathologic complete response was achieved in 10 patients. Overall sensitivity, false-negative rate (FNR), negative predictive value, and accuracy of hot/blue SLNB were 80.0%, 20.0%, 83.3%, and 90.0%, respectively. Retrieving more nodes and favorable nodal response were associated with improved performance. The best accuracy was observed when excised tattooed node was calculated together (FNR, 0.0%). Cold/non-blue tattooed nodes of five patients were removed during non-sentinel axillary surgery but clinicopathological parameters did not differ compared to patients with hot/blue tattooed node detected during SLNB, suggesting the importance of the tattooing procedure itself to improve performance.</P><P><B>Conclusion</B></P><P>Charcoal tattooing of cytology-confirmed metastatic ALN at presentation is technically feasible and does not limit SLNB after NCT. The tattooing procedure without additional preoperative localization is advantageous for improving the diagnostic performance of SLNB in this setting.</P>

Near-field phase correction for superresolution enhancement

Lee, Kwangchil,Jung, Youngjean,Kim, Kyoungsik American Physical Society 2009 Physical review. B, Condensed matter and materials Vol.80 No.3

<P>Although superresolution can be successfully obtained by negative index materials, the unavoidable losses ultimately limits image resolution. Using the near-field active phase-correction method, we theoretically predict the significant enhancement of both superresolution and transmission in a realistic lossy superlens system. In a SiC superlens system, resolvable separation between two slits significantly improves from lambda/4.2 to lambda/14.2 and the transmission increases 30.5 times compared to the conventional index match method.</P>

Intratumoral Agreement of High-Resolution Magic Angle Spinning Magnetic Resonance Spectroscopic Profiles in the Metabolic Characterization of Breast Cancer

Park, Vivian Youngjean,Yoon, Dahye,Koo, Ja Seung,Kim, Eun-Kyung,Kim, Seung Il,Choi, Ji Soo,Park, Seho,Park, Hyung Seok,Kim, Suhkmann,Kim, Min Jung,Zhou., Wen Wolters Kluwer Health 2016 Medicine Vol.95 No.15

<P><B>Abstract</B></P><P>High-resolution magic angle spinning (HR-MAS) magnetic resonance (MR) spectroscopy data may serve as a biomarker for breast cancer, with only a small volume of tissue sample required for assessment. However, previous studies utilized only a single tissue sample from each patient. The aim of this study was to investigate whether intratumoral location and biospecimen type affected the metabolic characterization of breast cancer assessed by HR-MAS MR spectroscopy</P><P>This prospective study was approved by the institutional review board and informed consent was obtained. Preoperative core-needle biopsies (CNBs), central, and peripheral surgical tumor specimens were prospectively collected under ultrasound (US) guidance in 31 patients with invasive breast cancer. Specimens were assessed with HR-MAS MR spectroscopy. The reliability of metabolite concentrations was evaluated and multivariate analysis was performed according to intratumoral location and biospecimen type.</P><P>There was a moderate or higher agreement between the relative concentrations of 94.3% (33 of 35) of metabolites in the center and periphery, 80.0% (28 of 35) of metabolites in the CNB and central surgical specimens, and 82.9% (29 of 35) of metabolites between all 3 specimen types. However, there was no significant agreement between the concentrations of phosphocholine (PC) and phosphoethanolamine (PE) in the center and periphery. The concentrations of several metabolites (adipate, arginine, fumarate, glutamate, PC, and PE) had no significant agreement between the CNB and central surgical specimens.</P><P>In conclusion, most HR-MAS MR spectroscopic data do not differ based on intratumoral location or biospecimen type. However, some metabolites may be affected by specimen-related variables, and caution is recommended in decision-making based solely on metabolite concentrations, particularly PC and PE. Further validation through future studies is needed for the clinical implementation of these biomarkers based on data from a single tissue sample.</P>

Robust optical measurement of water vapor in steel-making process

Haesung Park,Youngjean Jung,Kyoungsik Kim,Jinsu Bae,Jonghak Lee,Kyoungsik Kim 제어로봇시스템학회 2008 제어로봇시스템학회 국제학술대회 논문집 Vol.2008 No.10

Based on tunable diode laser spectroscopy (TDLS), we develop a simple and efficient humidity monitoring scheme to improve reliability of measurement under randomly changing transmission condition. This measurement scheme can detect the humidity of a monitored system in either high or low scattering condition such as powder coal fired furnace in steel-making process. Distributed feed-back (DFB) diode laser is used to evaluate the relative and absolute humidity by making direct absorption measurement near 938nm region where 2ν1 + ν3 water vapor transition band exists. This system gives reliable measurement results under either high or low scattering condition.

Elimination of phase singularity to achieve superresolution in lossy metamaterials

Lee, Kwangchil,Jung, Youngjean,Padilla, Willie J.,Kim, Kyoungsik The Optical Society 2010 Optics express Vol.18 No.12

<P>The presence of absorption losses softens the singular behavior of transmission resonances and leads to a good image in spite of limited effective spatial frequency range. Nonetheless, we found that the phase singularity does not disappear despite the considerably reduced retardation effects by softening the transmission resonances. Because the phase singularity severely deteriorates the ideal image reconstruction, broad transmission bandwidth in spatial frequency domain is not sufficient enough to achieve superresolution in TiO(2) thin film lens. The present work predicts successful elimination of the phase singularity and the achievement of approximately lambda /12.9 superresolution in TiO(2) thin film lens through the phase correction method.</P>

Prior to Breast MRI Guidelines in Korea, Where Were We?

Hwang, Cheong Hoon,Rho, Miribi,Lee, Minah,Kim, Ga Ram,Park, Vivian Youngjean,Yoon, Jung Hyun,Kim, Min Jung Korean Society of Magnetic Resonance in Medicine 2021 Investigative Magnetic Resonance Imaging Vol.25 No.1

Purpose: To evaluate and analyze the adequacy of breast magnetic resonance imaging (MRI)s taken before publication of the 2018 recommendation in South Korea. Materials and Methods: We enrolled 87 cases of breast MRIs, from January 2010 to November 2013, taken at external hospitals in the study. Breast MRI protocol elements are divided into three categories based on the recommendation by the Breast Imaging Study Group of the Korean Society of Magnetic Resonance: (1) Essential elements for breast MRI protocol; (2) Element to consider when evaluating imaging quality; and (3) Optional element for breast MRI protocol. Also, we divided enrolled cases into three groups based on their conducting locations -- (1) Primary hospitals, (2) Secondary hospitals, and (3) Tertiary hospitals-and analyzed them for the adequacy of imaging protocols based on the 2018 recommendation. We used a Chi-square test and Fisher's exact test to identify differences between categorical variables. Results: Over 98% of the criteria for 'essential elements for breast MRI protocol' were satisfied when compared with the 2018 Recommendation. Over 96% of the criteria for 'elements to consider when evaluating imaging quality' were also satisfied, except for the slice thickness (83.9%). Optional elements for breast MRI protocol were satisfied with various percentages. There were no statistically significant differences between groups of tertiary, secondary, and primary hospitals; however, 3 tesla of MRI (P = 0.04), subtraction image protocol (P = 0.032), and DWI protocol (P = 0.03) were used more frequently in the tertiary hospitals than in the others. Conclusion: We found that the categories of 'essential elements' and 'elements to consider when evaluating imaging quality' were satisfied at 98% and 96%, respectively, when compared with the 2018 Recommendation by the Breast Imaging Study Group of the Korean Society of Magnetic Resonance.