1.Identification of Preeclamptic Placenta in Whole Slide Images Using Artificial Intelligence Placenta Analysis
Young Mi JUNG ; Seyeon PARK ; Youngbin AHN ; Haeryoung KIM ; Eun Na KIM ; Hye Eun PARK ; Sun Min KIM ; Byoung Jae KIM ; Jeesun LEE ; Chan-Wook PARK ; Joong Shin PARK ; Jong Kwan JUN ; Young-Gon KIM ; Seung Mi LEE
Journal of Korean Medical Science 2024;39(39):e271-
Background:
Preeclampsia (PE) is a hypertensive pregnancy disorder linked to placental dysfunction, often involving pathological lesions like acute atherosis, decidual vasculopathy, accelerated villous maturation, and fibrinoid deposition. However, there is no gold standard for the pathological diagnosis of PE and this limits the ability of clinicians to distinguish between PE and non-PE pregnancies. Recent advances in computational pathology have provided the opportunity to automate pathological analysis for diagnosis, classification, prediction, and prediction of disease progression. In this study, we assessed whether computational pathology could be used to identify PE placentas.
Methods:
A total of 168 placental whole-slide images (WSIs) of patients from Seoul National University Hospital (comprising 84 PE cases and 84 normal controls) were used for model development and internal validation. For external validation of the model, 76 placental slides (including 38 PE cases and 38 normal controls) were obtained from the Boramae Medical Center (BMC). To establish standard criteria for diagnosing PE and distinguishing it from controls using placental WSIs, patch characteristics and quantification of terminal and intermediate villi were employed. In unsupervised learning, K-means clustering was conducted as a feature obtained through an Auto Encoder to extract the ratio of each cluster for each WSI. For supervised learning, quantitative assessments of the villi were obtained using a U-Net-based segmentation algorithm. The prediction model was developed using an ensemble method and was compared with a clinical feature model developed by using placental size features.
Results:
Using ensemble modeling, we developed a model to identify PE placentas.The model showed good performance (area under the precision-recall curve [AUPRC], 0.771; 95% confidence interval [CI], 0.752–0.790), with 77.3% of sensitivity and 71.1% of specificity, whereas the clinical feature model showed an AUPRC 0.713 (95% CI, 0.694–0.732) with 55.6% sensitivity and 86.8% specificity. External validation of the predictive model employing the BMC-derived set of placental slides also showed good discrimination (AUPRC, 0.725; 95% CI, 0.720–0.730).
Conclusion
The proposed computational pathology model demonstrated a strong ability to identify preeclamptic placentas. Computational pathology has the potential to improve the identification of PE placentas.
2.Central Neurogenic Hyperventilation Following Ischemic Stroke in the Pons
Hyeo Seo MOON ; Byoung Wook HWANG ; Min A LEE ; Chang Ju LEE ; Ju Hye KIM ; Jun Hyeok PARK ; Seong Hwan AHN
Journal of the Korean Neurological Association 2024;42(3):245-247
Central neurogenic hyperventilation (CNH) is a rare condition that characterized by an increase in the rate and depth of respiration to an extent that produces advanced respiratory alkalosis due to various central nervous disorder. The mechanism of CNH remains unclear. We reported a case of CNH in patients with progressive ischemic stroke in pons, including parabrachial nucleus, which is thought to have disrupted inhibitory impulses to the medullary respiratory center.
3.Feasibility of the Threshold-Based Quantification of Myocardial Fibrosis on Cardiac CT as a Prognostic Marker in Nonischemic Dilated Cardiomyopathy
Na Young KIM ; Dong Jin IM ; Yoo Jin HONG ; Byoung Wook CHOI ; Seok-Min KANG ; Jong-Chan YOUN ; Hye-Jeong LEE
Korean Journal of Radiology 2024;25(6):540-549
Objective:
This study investigated the feasibility and prognostic relevance of threshold-based quantification of myocardial delayed enhancement (MDE) on CT in patients with nonischemic dilated cardiomyopathy (NIDCM).
Materials and Methods:
Forty-three patients with NIDCM (59.3 ± 17.1 years; 21 male) were included in the study and underwent cardiac CT and MRI. MDE was quantified manually and with a threshold-based quantification method using cutoffs of 2, 3, and 4 standard deviations (SDs) on three sets of CT images (100 kVp, 120 kVp, and 70 keV). Interobserver agreement in MDE quantification was assessed using the intraclass correlation coefficient (ICC). Agreement between CT and MRI was evaluated using the Bland-Altman method and the concordance correlation coefficient (CCC). Patients were followed up for the subsequent occurrence of the primary composite outcome, including cardiac death, heart transplantation, heart failure hospitalization, or appropriate use of an implantable cardioverter-defibrillator. The Kaplan–Meier method was used to estimate event-free survival according to MDE levels.
Results:
Late gadolinium enhancement (LGE) was observed in 29 patients (67%, 29/43), and the mean LGE found with the 5-SD threshold was 4.1% ± 3.6%. The 4-SD threshold on 70-keV CT showed excellent interobserver agreement (ICC = 0.810) and the highest concordance with MRI (CCC = 0.803). This method also yielded the smallest bias with the narrowest range of 95% limits of agreement compared to MRI (bias, -0.119%; 95% limits of agreement, -4.216% to 3.978%). During a median follow-up of 1625 days (interquartile range, 712–1430 days), 10 patients (23%, 10/43) experienced the primary composite outcome. Event-free survival significantly differed between risk subgroups divided by the optimal MDE cutoff of 4.3% (log-rank P = 0.005).
Conclusion
The 4-SD threshold on 70-keV monochromatic CT yielded results comparable to those of MRI for quantifying MDE as a marker of myocardial fibrosis, which showed prognostic value in patients with NIDCM.
4.Current Practice Patterns of Endoscopic Ultrasound-Guided Tissue Sampling for Pancreatic Solid Mass in Korea: Outcomes of a National Survey
Dong-Won AHN ; Hyung Ku CHON ; Sung-Hoon MOON ; Sang Wook PARK ; Woo Hyun PAIK ; Chang Nyol PAIK ; Byoung Kwan SON ; Tae Jun SONG ; Eaum Seok LEE ; Yun Nah LEE ; Yoon Suk LEE ; Jae Min LEE ; Tae Joo JEON ; Chang Hwan PARK ; Kwang Bum CHO ; Dong Wook LEE ; Hong Ja KIM ; Seung Bae YOON ; Kwang Hyun CHUNG ; Jin-Seok PARK
Gut and Liver 2023;17(2):328-336
Background/Aims:
Although endoscopic ultrasound (EUS)-guided fine needle aspiration (FNA) and fine needle biopsy (FNB) are widely used for tissue acquisition of pancreatic solid mass, the optimal strategy of this procedure has not been established yet. The aim of this nationwide study was to investigate the current practice patterns of EUS-FNA/FNB for pancreatic solid mass in Korea.
Methods:
The Policy-Quality Management of the Korean Pancreatobiliary Association (KPBA) developed a questionnaire containing 22 questions. An electronic survey consisting of the questionnaire was distributed by e-mail to members registered to the KPBA.
Results:
A total of 101 respondents completed the survey. Eighty respondents (79.2%) performed preoperative EUS-FNA/FNB for operable pancreatic solid mass. Acquire needles (60.4%) were used the most, followed by ProCore needles (47.5%). In terms of need size, most respondents (>80%) preferred 22-gauge needles regardless of the location of the mass. Negative suction with a 10-mL syringe (71.3%) as sampling technique was followed by stylet slow-pull (41.6%). More than three needle passes for EUS-FNA/FNB was performed by most respondents (>80%). The frequency of requiring repeated procedure was significantly higher in respondents with a low individual volume (<5 per month, p=0.001). Prophylactic antibiotics were routinely used in 39 respondents (38.6%); rapid on-site pathologic evaluation was used in 6.1%.
Conclusions
According to this survey, practices of EUS-FNA/FNB for pancreatic solid mass varied substantially, some of which differed considerably from the recommendations present in existing guidelines. These results suggest that the development of evidence-based quality guidelines fitting Korean clinical practice is needed to establish the optimal strategy for this procedure.
6.The Etiology of Acute Stroke with Experience of Repeated Upper Extremity Deep Vein Thrombosis
Chang Ju LEE ; Dong Kun LEE ; Min A LEE ; Byoung Wook HWANG ; Ju Hye KIM ; Hyeo Seo MOON ; Sung-Chul LIM ; Seong Hwan AHN
Journal of the Korean Neurological Association 2023;41(1):52-55
In stroke patients, upper extremity deep vein thrombosis (UEDVT) is uncommon compared with lower extremity. Unlike the blood stasis in lower extremity, UEDVT has been developed by secondary cause. We reported a case of stroke patient with repeated UEDVT, presenting superficial venous congestion, who was finally diagnosed with pulmonary adenocarcinoma. The cause of stroke was non-bacterial thromboembolism formed at the mitral valve. Our case shows that unexpected UEDVT should be closely evaluated for higher coagulable status such as a malignancy.
7.National Survey Regarding the Management of Difficult Bile Duct Stones in South Korea
Yoon Suk LEE ; Tae Joo JEON ; Woo Hyun PAIK ; Dong-Won AHN ; Kwang Hyun CHUNG ; Byoung Kwan SON ; Tae Jun SONG ; Sung-Hoon MOON ; Eaum Seok LEE ; Jae Min LEE ; Seung Bae YOON ; Chang Nyol PAIK ; Yun Nah LEE ; Jin-Seok PARK ; Dong Wook LEE ; Sang Wook PARK ; Hyung Ku CHON ; Kwang Bum CHO ; Chang Hwan PARK ;
Gut and Liver 2023;17(3):475-481
Background/Aims:
This study aimed to investigate the patterns of preferred endoscopic procedure types and techniques for managing difficult common bile duct (CBD) stones in South Korea.
Methods:
The Committee of Policy and Quality Management of Korean Pancreatobiliary Association (KPBA) conducted a survey containing 19 questions. Both paper and online surveys were carried out; with the paper survey being conducted during the 2019 Annual Congress of KPBA and the online survey being conducted through Google Forms from April 2020 to February 2021.
Results:
The response rate was approximately 41.3% (86/208). Sixty-two (73.0%) worked at tertiary hospitals or academic medical centers, and 60 (69.7%) had more than 5 years of endoscopic retrograde cholangiopancreatography experience. The preferred size criteria for large CBD stones were 15 mm (40.6%), 20 mm (31.3%), and 30 mm (4.6%). For managing of large CBD stones, endoscopic papillary large balloon dilation after endoscopic sphincterotomy was the most preferred technique (74.4%). When performing procedures in those with bleeding diathesis, 64 (74.4%) respondents favored endoscopic papillary balloon dilation (EPBD) alone or EPBD with small endoscopic sphincterotomy. Fifty-five respondents (63.9%) preferred the doubleguidewire technique when faced with difficult bile duct cannulation in patients with periampullary diverticulum. In surgically altered anatomies, cap-fitted forward viewing endoscopy (76.7%) and percutaneous transhepatic cholangioscopy (48.8%) were the preferred techniques for Billroth-II anastomosis and total gastrectomy with Roux-en-Y anastomosis, respectively.
Conclusions
Most respondents showed unifying trends for the management of difficult CBD stones. The current practice patterns could be used as basic data for clinical quality improvements in the management of difficult CBD stones.
8.Rescue Endovascular Treatment to Prevent Neurological Deterioration in Acute Symptomatic Bilateral Vertebral Artery Occlusion
Byoung Wook HWANG ; Min A LEE ; Sang Woo HA ; Jae Ho KIM ; Hak Sung KIM ; Seong Hwan AHN
Neurointervention 2023;18(3):182-189
Bilateral vertebral artery occlusive disease has been considered as a favorable condition with good collaterals. However, the prognosis of acute ischemic stroke secondary to symptomatic bilateral vertebral artery occlusion (BVAO) and endovascular treatment (EVT) has rarely been reported. We retrospectively selected patients with acute ischemic stroke admitted for symptomatic BVAO between January 2020 and February 2023. All patients with ischemic stroke were evaluated for ischemic lesion and arterial status using brain imaging and angiography. The prognosis of acute stroke with symptomatic BVAO was compared between EVT and conventional treatment. Outcomes were evaluated using modified Rankin Scale (mRS) score at 3 months follow-up. Within the study period, 17 of 2,655 acute ischemic stroke patients were diagnosed with ischemic stroke with symptomatic BVAO. The median age of these patients was 70 (interquartile range 44–89) years, and 13 (76%) were male. Seven patients received emergent EVT with stenting and 10 patients received conventional medical treatment only. Nine of 10 patients with conventional treatment had in-hospital stroke progression and developed new ischemic lesions in the pons and midbrain. Five patients with fetal and hypoplastic posterior communicating artery presented bilateral cerebral peduncular lesions. At 3 months follow-up, 6 patients (35%) had favorable outcomes (mRS 0–2), of which 5 were treated with vertebral artery stenting and 1 received conventional treatment. Ischemic stroke in patients with acute symptomatic BVAO is uncommon. However, stroke progression is common, and the prognosis of most patients is poor. Rescue management such as EVT might be considered for symptomatic BVAO.
9.Endovascular Reperfusion Therapy in Minor Stroke with Neurologic Deterioration beyond 24 Hours from Onset
Min A LEE ; Byoung Wook HWANG ; Sang Woo HA ; Jae Ho KIM ; Hak Sung KIM ; Seong Hwan AHN
Neurointervention 2023;18(3):159-165
Purpose:
Patients with minor stroke (National Institutes of Health Stroke Scale score ≤5) and large vessel occlusion (LVO) often experience neurological deterioration >24 hours after onset. However, the efficacy of endovascular reperfusion therapy in these patients remains unclear. The aim of this study was to determine the efficacy and safety of reperfusion therapy in patients with minor stroke and neurological deterioration >24 hours after onset.
Materials and Methods:
Data were retrospectively reviewed from patients between January 2019 and April 2022 who met the following criteria: (1) minor stroke and small definitive ischemic lesions at initial visit, (2) onset to neurological deterioration >24 hours, (3) cortical signs, Alberta Stroke Program Early computed tomography (CT) Score >6 points, and large artery occlusion confirmed by CT angiography at neurological deterioration. Efficacy and safety outcomes were based on final thrombolysis in cerebral infarction (TICI), incidence of symptomatic intracranial hemorrhage (ICH), and mortality. Outcomes were assessed using the modified Rankin Scale (mRS) at 3 months. Good outcome was defined as a mRS of 0, 1, or 2.
Results:
Data from 26 patients (38.4% female, mean age 75.8 years) were analyzed; 18 (69.2%) had a good outcome. A final TICI of 2b or 3 was observed in 24 (92.3%) patients. No other adverse events, including dissection, vasospasm or distal embolization, were observed during the procedures. Hemorrhagic events occurred in 8 patients after the procedure; however, there were no symptomatic ICHs. Good prognostic factors were younger age (P=0.062) and carotid stenting (P=0.025).
Conclusion
Endovascular reperfusion therapy performed in selected patients with minor stroke, LVO, and neurological deterioration >24 hours after stroke onset demonstrated favorable outcomes and safety.
10.Efficacy and safety of sofosbuvir–velpatasvir and sofosbuvir–velpatasvir–voxilaprevir for hepatitis C in Korea: a Phase 3b study
Jeong HEO ; Yoon Jun KIM ; Sung Wook LEE ; Youn-Jae LEE ; Ki Tae YOON ; Kwan Soo BYUN ; Yong Jin JUNG ; Won Young TAK ; Sook-Hyang JEONG ; Kyung Min KWON ; Vithika SURI ; Peiwen WU ; Byoung Kuk JANG ; Byung Seok LEE ; Ju-Yeon CHO ; Jeong Won JANG ; Soo Hyun YANG ; Seung Woon PAIK ; Hyung Joon KIM ; Jung Hyun KWON ; Neung Hwa PARK ; Ju Hyun KIM ; In Hee KIM ; Sang Hoon AHN ; Young-Suk LIM
The Korean Journal of Internal Medicine 2023;38(4):504-513
Despite the availability of direct-acting antivirals (DAAs) for chronic hepatitis C virus (HCV) infection in Korea, need remains for pangenotypic regimens that can be used in the presence of hepatic impairment, comorbidities, or prior treatment failure. We investigated the efficacy and safety of sofosbuvir–velpatasvir and sofosbuvir–velpatasvir–voxilaprevir for 12 weeks in HCV-infected Korean adults. Methods: This Phase 3b, multicenter, open-label study included 2 cohorts. In Cohort 1, participants with HCV genotype 1 or 2 and who were treatment-naive or treatment-experienced with interferon-based treatments, received sofosbuvir–velpatasvir 400/100 mg/day. In Cohort 2, HCV genotype 1 infected individuals who previously received an NS5A inhibitor-containing regimen ≥ 4 weeks received sofosbuvir–velpatasvir–voxilaprevir 400/100/100 mg/day. Decompensated cirrhosis was an exclusion criterion. The primary endpoint was SVR12, defined as HCV RNA < 15 IU/mL 12 weeks following treatment. Results: Of 53 participants receiving sofosbuvir–velpatasvir, 52 (98.1%) achieved SVR12. The single participant who did not achieve SVR12 experienced an asymptomatic Grade 3 ASL/ALT elevation on day 15 and discontinued treatment. The event resolved without intervention. All 33 participants (100%) treated with sofosbuvir–velpatasvir–voxilaprevir achieved SVR 12. Overall, sofosbuvir–velpatasvir and sofosbuvir–velpatasvir–voxilaprevir were safe and well tolerated. Three participants (5.6%) in Cohort 1 and 1 participant (3.0%) in Cohort 2 had serious adverse events, but none were considered treatment-related. No deaths or grade 4 laboratory abnormalities were reported. Conclusions: Treatment with sofosbuvir–velpatasvir or sofosbuvir–velpatasvir–voxilaprevir was safe and resulted in high SVR12 rates in Korean HCV patients.

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