Tricuspid Valve Imaging and Right Ventricular Function Analysis Using Cardiac CT and MRI

Ahn Yura,Koo Hyun Jung,Kang Joon-Won,Yang Dong Hyun 대한영상의학회 2021 Korean Journal of Radiology Vol.22 No.12

Cardiac computed tomography (CT) and cardiac magnetic resonance imaging (CMR) can reveal the detailed anatomy and function of the tricuspid valve and right ventricle (RV). Quantification of tricuspid regurgitation (TR) and analysis of RV function have prognostic implications. With the recently available transcatheter treatment options for diseases of the tricuspid valve, evaluation of the tricuspid valve using CT and CMR has become important in terms of patient selection and procedural guidance. Moreover, CT enables post-procedural investigation of the causes of valve dysfunction, such as pannus or thrombus. This review describes the anatomy of the tricuspid valve and CT and CMR imaging protocols for right heart evaluation, including RV function and TR analyses. We also demonstrate the pre-procedural planning for transcatheter treatment of TR and imaging of postoperative complications using CT.

Impact of the Liver Imaging Reporting and Data System on Research Studies of Diagnosing Hepatocellular Carcinoma Using MRI

Ahn Yura,Choi Sang Hyun,Jang Jong Keon,Kim So Yeon,심주현,Lee Seung Soo,Byun Jae Ho 대한영상의학회 2022 Korean Journal of Radiology Vol.23 No.5

Objective: Since its introduction in 2011, the CT/MRI diagnostic Liver Imaging Reporting and Data System (LI-RADS) has been updated in 2014, 2017, and 2018. We evaluated the impact of CT/MRI diagnostic LI-RADS on liver MRI research methodology for the diagnosis of hepatocellular carcinoma (HCC). Materials and Methods: The MEDLINE, EMBASE, and Cochrane databases were searched for original articles reporting the diagnostic performance of liver MRI for HCC between 2011 and 2019. The MRI techniques, image analysis methods, and diagnostic criteria for HCC used in each study were investigated. The studies were classified into three groups according to the year of publication (2011–2013, 2014–2016, and 2017–2019). We compared the percentage of studies adopting MRI techniques recommended by LI-RADS, image analysis methods in accordance with the lexicon defined in LI-RADS, and diagnostic criteria endorsed by LI-RADS. We compared the pooled sensitivity and specificity between studies that used the LI-RADS and those that did not. Results: This systematic review included 179 studies. The percentages of studies using imaging techniques recommended by LI-RADS were 77.8% for 2011–2013, 85.7% for 2014–2016, and 84.2% for 2017–2019, with no significant difference (p = 0.951). After the introduction of LI-RADS, the percentages of studies following the LI-RADS lexicon were 0.0%, 18.4%, and 56.6% in the respective periods (p < 0.001), while the percentages of studies using the LI-RADS diagnostic imaging criteria were 0.0%, 22.9%, and 60.7%, respectively (p < 0.001). Studies that did not use the LI-RADS and those that used the LIRADS version 2018 showed no significant difference in sensitivity and specificity (86.3% vs. 77.7%, p = 0.102 and 91.4% vs. 89.9%, p = 0.770, respectively), with some difference in heterogeneity (I2 = 94.3% vs. 86.7% in sensitivity and I2 = 86.6% vs. 53.2% in specificity). Conclusion: LI-RADS imparted significant changes in the image analysis methods and diagnostic criteria used in liver MRI research for the diagnosis of HCC.

Prognostic Implication of Right Ventricle Parameters Measured on Preoperative Cardiac MRI in Patients with Functional Tricuspid Regurgitation

Ahn Yura,Koo Hyun Jung,Kang Joon-Won,Choi Won Jin,Kim Dae-Hee,Song Jong-Min,Kang Duk-Hyun,Song Jae-Kwan,Kim Joon Bum,Jung Sung-Ho,Choo Suk Jung,Chung Cheol Hyun,Lee Jae Won,Yang Dong Hyun 대한영상의학회 2021 Korean Journal of Radiology Vol.22 No.8

Objective: To investigate the prognostic value of preoperative cardiac magnetic resonance imaging (MRI) for long-term major adverse cardiac and cerebrovascular events (MACCEs) in patients undergoing tricuspid valve (TV) surgery for functional tricuspid regurgitation (TR). Materials and Methods: The preoperative cardiac MR images, New York Heart Association functional class, comorbidities, and clinical events of 78 patients (median [interquartile range], 59 [51–66.3] years, 28.2% male) who underwent TV surgery for functional TR were comprehensively reviewed. Cox proportional hazards analyses were performed to assess the associations of clinical and imaging parameters with MACCEs and all-cause mortality. Results: For the median follow-up duration of 5.4 years (interquartile range, 1.2–6.6), MACCEs and all-cause mortality were 51.3% and 23.1%, respectively. The right ventricular (RV) end-systolic volume index (ESVI) and the systolic RV mass index (RVMI) were higher in patients with MACCEs than those without them (77 vs. 68 mL/m2, p = 0.048; 23.5 vs. 18.0%, p = 0.011, respectively). A high RV ESVI was associated with all-cause mortality (hazard ratio [HR] per value of 10 higher ESVI = 1.10, p = 0.03). A high RVMI was also associated with all-cause mortality (HR per increase of 5 mL/m2 RVMI = 1.75, p < 0.001). After adjusting for age and sex, only RVMI remained a significant predictor of MACCEs and all-cause mortality (p < 0.05 for both). After adjusting for multiple clinical variables, RVMI remained significantly associated with all-cause mortality (p = 0.005). Conclusion: RVMI measured on preoperative cardiac MRI was an independent predictor of long-term outcomes in patients who underwent TV surgery for functional TR.

Deep Learning Algorithm for Automated Segmentation and Volume Measurement of the Liver and Spleen Using Portal Venous Phase Computed Tomography Images

Ahn Yura,Yoon Jee Seok,Lee Seung Soo,Suk Heung-Il,Son Jung Hee,Sung Yu Sub,Lee Yedaun,Kang Bo-Kyeong,Kim Ho Sung 대한영상의학회 2020 Korean Journal of Radiology Vol.21 No.8

Objective: Measurement of the liver and spleen volumes has clinical implications. Although computed tomography (CT) volumetry is considered to be the most reliable noninvasive method for liver and spleen volume measurement, it has limited application in clinical practice due to its time-consuming segmentation process. We aimed to develop and validate a deep learning algorithm (DLA) for fully automated liver and spleen segmentation using portal venous phase CT images in various liver conditions. Materials and Methods: A DLA for liver and spleen segmentation was trained using a development dataset of portal venous CT images from 813 patients. Performance of the DLA was evaluated in two separate test datasets: dataset-1 which included 150 CT examinations in patients with various liver conditions (i.e., healthy liver, fatty liver, chronic liver disease, cirrhosis, and post-hepatectomy) and dataset-2 which included 50 pairs of CT examinations performed at ours and other institutions. The performance of the DLA was evaluated using the dice similarity score (DSS) for segmentation and Bland-Altman 95% limits of agreement (LOA) for measurement of the volumetric indices, which was compared with that of ground truth manual segmentation. Results: In test dataset-1, the DLA achieved a mean DSS of 0.973 and 0.974 for liver and spleen segmentation, respectively, with no significant difference in DSS across different liver conditions (p = 0.60 and 0.26 for the liver and spleen, respectively). For the measurement of volumetric indices, the Bland-Altman 95% LOA was -0.17 ± 3.07% for liver volume and -0.56 ± 3.78% for spleen volume. In test dataset-2, DLA performance using CT images obtained at outside institutions and our institution was comparable for liver (DSS, 0.982 vs. 0.983; p = 0.28) and spleen (DSS, 0.969 vs. 0.968; p = 0.41) segmentation. Conclusion: The DLA enabled highly accurate segmentation and volume measurement of the liver and spleen using portal venous phase CT images of patients with various liver conditions.

Primary Extragonadal Germ Cell Tumors in Klinefelter Syndrome: 10-Years of Experience from a Single Institute

Yura Kim,Won Kee Ahn,한정우,Seung Min Hahn,Seung Yeon Kwon,유철주 대한소아혈액종양학회 2020 Clinical Pediatric Hematology-Oncology Vol.27 No.1

Background: Approximately 8% of male patients presenting with primary mediastinal germ cell tumors (GCTs) have Klinefelter syndrome (KS), while patients diagnosed with retroperitoneal GCTs also exhibit a range of chromosomal abnormalities. The exact mechanism underlying the development of GCTs in Klinefelter syndrome is unknown, but KS frequently goes underdiagnosed as a result of its varied symptoms and a low general awareness of this condition. Thus, the Children’s Oncology Group recommends screening of Klinefelter syndrome in pediatric and adolescent male subjects who present with GCTs. Methods: We retrospectively reviewed the medical records of extragonadal germ cell tumor patients treated at Severance hospital, department of pediatrics or division of pediatric hematology-oncology over the last ten years. Results: A total of 95 patients with extragonadal germ cell tumors were included in this study. Karyotyping was done in eight patients out of 95 patients, three patients with KS and one patient with Down syndrome. Twelve of extragonadal GCT patients presented at mediastinum, with most common histology of mature teratoma, and three patients presented with chromosomal abnormalities, two with KS and one with Down syndrome. A total of nine patients were diagnosed with retroperitoneal GCTs and only one had KS. Conclusion: We described the characteristics of 95 cases of extragonadal GCTs. Although the mechanism of extragonadal GCTs in KS is not clear, karyotyping in pediatric and adolescent extragonadal GCT patients could be helpful in figuring out chromosomal abnormalities including KS and their roles in GCT pathophysiology, which can contribute to improve one’s health.

측면 시인성 향상을 위한 헤드램프

차유라(Yura Cha),안병석(Byoungsuk Ahn),장래웅(Raewoong Jang),조후택(Hootaek Cho) 한국자동차공학회 2010 한국자동차공학회 부문종합 학술대회 Vol.2010 No.5

In spite of satisfying the headlamp regulation, the side of the car is not illuminated enough. To solve this problem, the headlamp has been developed various ways. Using hid bulb, changing the illumination spread(dynamic-bending light) or supplementing the additional light source(static-bending light, cornering light). The first part of this paper compare the performance of the dynamic-bending light and the cornering light with the static-bending light. From this investigation we reached the conclusion that the static-bending light is the most effective way. The second part we suggest the setting parameter for the design optimization of the static-bending light.

Electrochemically polyaniline-coated microextraction needle for phthalates in water

Hwang, Yura,Lee, Yelin,Ahn, Soyoung,Bae, Sunyoung The Korean Society of Analytical Science 2020 분석과학 Vol.33 No.2

A stainless-steel needle (Hamilton 90022, 22 gauge, 718-㎛ o.d., 413-㎛ i.d., 51-mm length, bevel tip) with an electrochemically coated polyaniline layer having a microbore tunnel was newly prepared as a device for headspace in-needle microextraction. For designing the needle, the polyaniline layer length was optimized, and to evaluate the extraction efficiency for polycyclic aromatic hydrocarbons, numerous cyclic voltammetry scans were conducted. In addition, the optimization of the analytical conditions (including the adsorption and desorption parameters) and the validation of the analytical method were conducted. The optimized adsorption and desorption conditions were 40 ℃ for 30 min and 230 ℃ for 60 s, respectively. Finally, in this study, a polyaniline layer was electrochemically deposited on the in-needle surface, and it exhibited good thermal stability. The needle with the polyaniline layer was repeatedly used more than 200 times during this study. This method has some advantages in terms of the extraction time, extraction efficiency, and analysis cost.

Clinical Effect of Progressive Pulmonary Fibrosis on Patients with Connective Tissue Disease-associated Interstitial Lung Disease: A Single Center Retrospective Cohort Study

( Ju Kwang Lee ),( Yura Ahn ),( Han Na Noh ),( Sang Min Lee ),( Bin Yoo ),( Chang-keun Lee ),( Yong-gil Kim ),( Seokchan Hong ),( Soo Min Ahn ),( Ho Cheol Kim ) 대한결핵 및 호흡기학회 2023 대한결핵 및 호흡기학회 추계학술대회 초록집 Vol.136 No.0

Stress Fracture of the Capitate

Cho, Hyung Joon,Hong, Ki Taek,Kang, Chang Ho,Ahn, Kyung-Sik,Kim, Yura,Hwang, Sung Tae Korean Society of Magnetic Resonance in Medicine 2018 Investigative Magnetic Resonance Imaging Vol.22 No.2

Most capitate fractures occur in association with additional carpal injuries, particularly scaphoid fractures. Isolated fractures of the capitate account for only 0.3% of carpal injuries, and stress fractures are one form of this fracture. We report the case of a 20-year-old male who had a stress fracture of the capitate after serving as an honor guard in the military. Conventional radiographs and computed tomography of the right wrist revealed a minimally displaced fracture line located at the midcarpal aspect of the right capitate. A magnetic resonance imaging scan demonstrates a subarticular capitate fracture with diffuse bone marrow edema, small osteophytes, and irregularity of the midcarpal articular cartilage. We also review the carpal kinematics which possibly caused the stress fracture. Although stress fractures of the capitate are rare, they should also be accounted for with patients who perform repetitive motions of the wrist to a considerable extent.

Rare Neurovascular Diseases in Korea: Classification and Related Genetic Variants

Song Yunsun,Kwon Boseong,Al-Abdulwahhab Abdulrahman Hamed,Nam Yeo Kyoung,Ahn Yura,Jeong So Yeong,Seo Eul-Ju,Lee Jong-Keuk,Suh Dae Chul 대한영상의학회 2021 Korean Journal of Radiology Vol.22 No.8

Rare neurovascular diseases (RNVDs) have not been well-recognized in Korea. They involve the central nervous system and greatly affect the patients’ lives. However, these diseases are difficult to diagnose and treat due to their rarity and incurability. We established a list of RNVDs by referring to the previous literature and databases worldwide to better understand the diseases and their current management status. We categorized 68 RNVDs based on their pathophysiology and clinical manifestations and estimated the prevalence of each disease in Korea. Recent advances in genetic, molecular, and developmental research have enabled further understanding of these RNVDs. Herein, we review each disease, while considering its classification based on updated pathologic mechanisms, and discuss the management status of RNVD in Korea.