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Dive into the research topics where Vivian Youngjean Park is active.

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Featured researches published by Vivian Youngjean Park.


Radiographics | 2013

Second-Look US: How to Find Breast Lesions with a Suspicious MR Imaging Appearance

Vivian Youngjean Park; Min Jung Kim; Eun-Kyung Kim; Hee Jung Moon

Breast magnetic resonance (MR) imaging has high sensitivity in breast cancer diagnosis. The probability of malignancy for additional detected lesions is higher in patients with breast cancer than in the population without malignancy, which is why biopsy or further study should be considered for additional detected lesions. Because of the shortcomings of MR imaging-guided biopsy, second-look ultrasonography (US) may be the preferred next step. Detecting target lesions at second-look US and correlating lesions between the two modalities may be challenging. Using axial MR imaging to localize the lesion with respect to the nipple and the lesion-to-nipple distance can narrow the scan range at US. Evaluating the lesions location relative to the mammary zones and surrounding tissues, as well as noting its depth, characteristics, and nearby landmarks, will aid in lesion correlation. Doppler imaging, tissue harmonic imaging, and other US techniques can be used to identify subtle lesions. Although malignant breast lesions may appear probably benign at second-look US, decision making for biopsy must be based primarily on MR imaging findings. In sonographically occult, MR imaging-detected lesions with suspicious MR imaging features, the probability of malignancy is much higher than 2%, and MR imaging-guided biopsy must be performed.


Liver International | 2014

Dynamic enhancement pattern of HCC smaller than 3 cm in diameter on gadoxetic acid‐enhanced MRI: comparison with multiphasic MDCT

Vivian Youngjean Park; Jin-Young Choi; Yong Eun Chung; Honsoul Kim; Mi-Suk Park; Joon Seok Lim; Ki Whang Kim; Myeong-Jin Kim

The dynamic enhancement pattern of HCCs smaller than 3 cm in diameter on gadoxetic acid‐enhanced magnetic resonance imaging (MRI) have not been extensively investigated. We aimed to evaluate the dynamic enhancement patterns of small HCCs (≤3 cm) on gadoxetic acid‐enhanced magnetic resonance imaging (MRI) and compare enhancement patterns with multiphasic multidetector computed tomography (MDCT) based on tumour cellular differentiation and size.


Ultrasound in Medicine and Biology | 2016

Thyroid Imaging Reporting and Data System and Ultrasound Elastography: Diagnostic Accuracy as a Tool in Recommending Repeat Fine-Needle Aspiration for Solid Thyroid Nodules with Non-Diagnostic Fine-Needle Aspiration Cytology

Vivian Youngjean Park; Eun-Kyung Kim; Jin Young Kwak; Jung Hyun Yoon; Min Jung Kim; Hee Jung Moon

The Thyroid Imaging Reporting and Data System (TIRADS) has been found to be accurate in the stratification of malignancy risk, and elastography has been found to have a high negative predictive value in non-diagnostic thyroid nodules. Through assessment of 104 solid non-diagnostic thyroid nodules, this study investigated the role of both in recommending repeat ultrasonography-guided fine-needle aspiration for solid thyroid nodules with non-diagnostic cytology. All nodules were classified by TIRADS (categories 4a, 4b, 4c and 5), and elastography scores were assigned according to the Rago and Asteria criteria. The malignancy risks for TIRADS categories 4a, 4b, 4c and 5 were 12.5%, 25.0%, 25.8% and 16.7%, respectively. Elastography revealed the highest diagnostic performance for TIRADS category 4a, with a sensitivity, specificity, negative predictive value, positive predictive value and accuracy of 100%, 85.7%, 100%, 50% and 87.5% for the Asteria criteria. Observation may be considered for non-diagnostic solid nodules that have no other suspicious ultrasonographic features and are also benign on real-time strain elastography using the Asteria criteria.


Acta Radiologica | 2016

Breast parenchymal signal enhancement ratio at preoperative magnetic resonance imaging: association with early recurrence in triple-negative breast cancer patients.

Vivian Youngjean Park; Eun-Kyung Kim; Min Jung Kim; Jung Hyun Yoon; Hee Jung Moon

Background The signal enhancement ratio (SER) of surrounding non-tumor parenchyma at breast magnetic resonance imaging (MRI) can be helpful in breast cancer patients, but has not been investigated in patients with triple negative breast cancer (TNBC). Purpose To investigate the association between background parenchymal SER around the tumor on preoperative dynamic contrast-enhanced MRI with recurrence-free survival in patients with TNBC. Material and Methods Between April 2012 and May 2013, 71 TNBC patients who underwent preoperative MRI were included. SER values were calculated from regions of interest placed in the breast parenchyma around the tumor. Cox proportional hazards models were used to determine associations between MRI variables, clinical-pathologic variables, and recurrence-free survival. Results Recurrence occurred in 8.5% (6/71) of patients. At univariate analysis, a higher SER around the tumor, larger tumor size, lymphovascular invasion, lymph node metastasis, receipt of neoadjuvant chemotherapy, receipt of total mastectomy, and not receiving adjuvant chemotherapy were associated with worse recurrence-free survival. At multivariate analysis of preoperative variables, a higher SER around the tumor was independently associated with worse recurrence-free survival (hazard ratio [HR] = 7.072, P = 0.003 for SER1; HR = 6.268, P = 0.006 for SER2; HR = 3.004, P = 0.039 for SER3). Conclusion Higher SER around the tumor at preoperative dynamic contrast-enhanced MRI is an independent predictor for recurrence in TNBC patients.


Medicine | 2016

The thyroid imaging reporting and data system on US, but not the BRAFV600E mutation in fine-needle aspirates, is associated with lateral lymph node metastasis in PTC.

Vivian Youngjean Park; Eun-Kyung Kim; Hee Jung Moon; Jung Hyun Yoon; Jin Young Kwak

AbstractThe majority of patients with papillary thyroid carcinoma (PTC) have an excellent prognosis, but some show poorer outcomes and would benefit from adjunctive prognostic tools. The B-Raf proto-oncogene, serine/threonine kinase (BRAF)V600E mutation, either based on both its presence or its quantitative measurement, and ultrasound (US) features may serve as a prognostic marker. The aim of this study was to investigate (1) the association between clinical-pathologic prognostic factors and the BRAFV600E mutation found in fine-needle aspirates, based on both its presence and its corresponding cycle threshold (Ct) value, and (2) the association between prognostic factors and suspicious US features classified by the thyroid imaging reporting and data system (TIRADS) in PTC.Two-hundred fifty-eight consecutive patients with PTC > 1 cm and who underwent preoperative US-guided fine-needle aspiration were included in this retrospective study. Clinical-pathologic variables were compared between patients with and without the BRAFV600E mutation. Multivariate analyses were performed to investigate (1) the association between clinical-pathologic prognostic factors and the BRAF V600Emutation found in fine-needle aspirates, based on both its presence and corresponding Ct values, and (2) the association between prognostic factors and suspicious TIRADS US features.BRAFV600E-positive patients had a higher proportion of multiple tumors (P = 0.017). The number of suspicious US features classified by the TIRADS was an independent factor for predicting lateral lymph node metastasis, both in all 258 patients (odds ratio [OR] = 1.902, P = 0.005) and in 214 BRAFV600E-positive patients (OR = 1.686, P = 0.037). The BRAFV600E mutation status or BRAFV600ECt values were not associated with any of the clinical-pathologic prognostic factors.In conclusion, a higher number of suspicious US features classified by the TIRADS, but not the BRAFV600E mutation, are associated with lateral lymph node metastasis in patients with PTC, and can aid in the preoperative identification of patients at increased risk of lateral lymph node metastasis.


American Journal of Roentgenology | 2017

Perfusion Parameters on Breast Dynamic Contrast-Enhanced MRI Are Associated With Disease-Specific Survival in Patients With Triple-Negative Breast Cancer

Vivian Youngjean Park; Eun-Kyung Kim; Min Jung Kim; Jung Hyun Yoon; Hee Jung Moon

OBJECTIVE The aim of this study was to investigate the association between perfusion parameters on MRI performed before treatment and survival outcome (disease-free survival [DFS], disease-specific survival [DSS]) in patients with triple-negative breast cancer (TNBC). MATERIALS AND METHODS Sixty-one patients (median age, 50 years; age range, 27-77 years) with TNBC (tumor size on MRI: median, 25.5 mm; range, 11.0-142.0 mm) were included. We analyzed clinical and pathologic variables and MRI parameters. Cox proportional hazards models were used to determine associations with survival outcome. RESULTS The median follow-up time was 46.1 months (range, 13.9-58.4 months). Eleven of 61 (18.0%) patients had events (i.e., local, regional, or distant recurrence or contralateral breast cancer) and seven (11.5%) died of breast cancer. Among the pretreatment variables, a larger tumor size on MR images (hazard ratio [HR] = 1.024, p = 0.003) was associated with worse DFS at univariate analysis. In multivariate pretreatment models for DSS, a higher fractional volume of extravascular extracellular space per unit volume of tissue (ve) value (HR = 1.658, p = 0.038), higher peak enhancement (HR = 1.843, p = 0.018), and a larger tumor size on MR images (HR = 1.060, p = 0.001) were associated with worse DSS. In multivariate posttreatment models, a larger pathologic tumor size (HR for DFS, 1.074 [p = 0.005]; HR for DSS, 1.050 [p = 0.042]) and metastasis in surgically resected axillary lymph nodes (HR for DFS, 5.789 [p = 0.017]; HR for DSS, 23.717 [p = 0.005]) were associated with worse survival outcome. CONCLUSION A higher ve value, higher peak enhancement, and larger tumor size of the primary tumor on pretreatment MRI were independent predictors of worse DSS in patients with TNBC.


PLOS ONE | 2016

Metabolomics of Breast Cancer Using High-Resolution Magic Angle Spinning Magnetic Resonance Spectroscopy: Correlations with 18F-FDG Positron Emission Tomography-Computed Tomography, Dynamic Contrast-Enhanced and Diffusion-Weighted Imaging MRI.

Haesung Yoon; Dahye Yoon; Mijin Yun; Ji Soo Choi; Vivian Youngjean Park; Eun-Kyung Kim; Joon Jeong; Ja Seung Koo; Jung Hyun Yoon; Hee Jung Moon; Suhkmann Kim; Min Jung Kim

Purpose Our goal in this study was to find correlations between breast cancer metabolites and conventional quantitative imaging parameters using high-resolution magic angle spinning (HR-MAS) magnetic resonance spectroscopy (MRS) and to find breast cancer subgroups that show high correlations between metabolites and imaging parameters. Materials and methods Between August 2010 and December 2013, we included 53 female patients (mean age 49.6 years; age range 32–75 years) with a total of 53 breast lesions assessed by the Breast Imaging Reporting and Data System. They were enrolled under the following criteria: breast lesions larger than 1 cm in diameter which 1) were suspicious for malignancy on mammography or ultrasound (US), 2) were pathologically confirmed to be breast cancer with US-guided core-needle biopsy (CNB) 3) underwent 3 Tesla MRI with dynamic contrast-enhanced (DCE) and diffusion-weighted imaging (DWI) and positron emission tomography-computed tomography (PET-CT), and 4) had an attainable immunohistochemistry profile from CNB. We acquired spectral data by HR-MAS MRS with CNB specimens and expressed the data as relative metabolite concentrations. We compared the metabolites with the signal enhancement ratio (SER), maximum standardized FDG uptake value (SUV max), apparent diffusion coefficient (ADC), and histopathologic prognostic factors for correlation. We calculated Spearman correlations and performed a partial least squares-discriminant analysis (PLS-DA) to further classify patient groups into subgroups to find correlation differences between HR-MAS spectroscopic values and conventional imaging parameters. Results In a multivariate analysis, the PLS-DA models built with HR-MAS MRS metabolic profiles showed visible discrimination between high and low SER, SUV, and ADC. In luminal subtype breast cancer, compared to all cases, high SER, ADV, and SUV were more closely clustered by visual assessment. Multiple metabolites were correlated with SER and SUV in all cases. Multiple metabolites showed correlations with SER and SUV in the ER positive, HER2 negative, and Ki-67 negative groups. Conclusion High levels of PC, choline, and glycine acquired from HR-MAS MRS using CNB specimens were noted in the high SER group via DCE MRI and the high SUV group via PET-CT, with significant correlations between choline and SER and between PC and SUV. Further studies should investigate whether HR-MAS MRS using CNB specimens can provide similar or more prognostic information than conventional quantitative imaging parameters.


Cancer Research and Treatment | 2017

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

Seho Park; Ja Seung Koo; Gun Min Kim; Joo Hyuk Sohn; Seung Il Kim; Young Up Cho; Byeong Woo Park; Vivian Youngjean Park; Jung Hyun Yoon; Hee Jung Moon; Min Jung Kim; Eun-Kyung Kim

Purpose 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. Materials and Methods 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. Results 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. Conclusion 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.


Medicine | 2016

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

Vivian Youngjean Park; Dahye Yoon; Ja Seung Koo; Eun-Kyung Kim; Seung Il Kim; Ji Soo Choi; Seho Park; Hyung Seok Park; Suhkmann Kim; Min Jung Kim

AbstractHigh-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 spectroscopyThis 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.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.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.


Medicine | 2015

Real-Time PCR Cycle Threshold Values for the BRAFV600E Mutation in Papillary Thyroid Microcarcinoma May Be Associated With Central Lymph Node Metastasis: A Retrospective Study

Vivian Youngjean Park; Eun-Kyung Kim; Hye Sun Lee; Hee Jung Moon; Jung Hyun Yoon; Jin Young Kwak

AbstractPapillary thyroid microcarcinoma (PTMC) usually has excellent prognosis, but a small subset shows aggressive behavior. Although the B-Raf proto-oncogene, serine/threonine kinase (BRAF)V600E mutation is the most common oncogenic alteration in PTMCs, it is frequently heterogeneously distributed within tumors. The aim of this study was to investigate the association of the BRAFV600E mutation found in fine needle aspirates from PTMCs with known clinicopathologic prognostic factors, based on both its presence and a quantitative approach that uses cycle threshold (Ct) values obtained by a real-time PCR technique.The 460 PTMC patients were included, with 367 patients having the BRAFV600E mutation. Clinicopathologic variables were compared between patients with and without the BRAFV600E mutation. BRAFV600E Ct values were compared according to clinicopathologic prognostic factors. Multivariate analyses were performed to evaluate factors predicting extrathyroidal extension and central and lateral lymph node metastasis (LNM). Each analysis used either the BRAFV600E mutation status or the Ct value as an independent variable for all the study patients and the 367 BRAFV600E-positive patients. Receiver-operating characteristic (ROC) curve analysis was performed to evaluate the diagnostic performance of BRAFV600E Ct values in predicting central and lateral LNM.The BRAFV600E mutation status was not associated with clinicopathologic prognostic factors among the 460 PTMC patients. Of the 367 BRAFV600E-positive patients, Ct values were significantly lower in patients with central and lateral LNM (P < 0.001, P = 0.007). The Ct value was the only independent factor to predict central LNM (OR 0.918, P = 0.025). The area under the ROC curve (AUC) for diagnosing central LNM was 0.623 (sensitivity, 50.0%; specificity, 71.9%) and for diagnosing lateral LNM, it was 0.796 (sensitivity, 71.4%; specificity, 94.7%).In conclusion, real-time PCR Ct values for the BRAFV600E mutation obtained from fine needle aspirates can be associated with central LNM in PTMC patients. Although BRAFV600E Ct values did not reach statistical significance for predicting lateral LNM in our study, further validation through larger studies can be used to overcome any possible type-II errors. With further studies, Ct values for the BRAFV600E mutation obtained from fine needle aspirates may have important implications for predicting both central and lateral LNM in patients with PTMCs.

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Dahye Yoon

Pusan National University

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