1.Deep Learning-Based Automatic Classification of Ischemic Stroke Subtype Using Diffusion-Weighted Images
Wi-Sun RYU ; Dawid SCHELLINGERHOUT ; Hoyoun LEE ; Keon-Joo LEE ; Chi Kyung KIM ; Beom Joon KIM ; Jong-Won CHUNG ; Jae-Sung LIM ; Joon-Tae KIM ; Dae-Hyun KIM ; Jae-Kwan CHA ; Leonard SUNWOO ; Dongmin KIM ; Sang-Il SUH ; Oh Young BANG ; Hee-Joon BAE ; Dong-Eog KIM
Journal of Stroke 2024;26(2):300-311
Background:
and Purpose Accurate classification of ischemic stroke subtype is important for effective secondary prevention of stroke. We used diffusion-weighted image (DWI) and atrial fibrillation (AF) data to train a deep learning algorithm to classify stroke subtype.
Methods:
Model development was done in 2,988 patients with ischemic stroke from three centers by using U-net for infarct segmentation and EfficientNetV2 for subtype classification. Experienced neurologists (n=5) determined subtypes for external test datasets, while establishing a consensus for clinical trial datasets. Automatically segmented infarcts were fed into the model (DWI-only algorithm). Subsequently, another model was trained, with AF included as a categorical variable (DWI+AF algorithm). These models were tested: (1) internally against the opinion of the labeling experts, (2) against fresh external DWI data, and (3) against clinical trial dataset.
Results:
In the training-and-validation datasets, the mean (±standard deviation) age was 68.0±12.5 (61.1% male). In internal testing, compared with the experts, the DWI-only and the DWI+AF algorithms respectively achieved moderate (65.3%) and near-strong (79.1%) agreement. In external testing, both algorithms again showed good agreements (59.3%–60.7% and 73.7%–74.0%, respectively). In the clinical trial dataset, compared with the expert consensus, percentage agreements and Cohen’s kappa were respectively 58.1% and 0.34 for the DWI-only vs. 72.9% and 0.57 for the DWI+AF algorithms. The corresponding values between experts were comparable (76.0% and 0.61) to the DWI+AF algorithm.
Conclusion
Our model trained on a large dataset of DWI (both with or without AF information) was able to classify ischemic stroke subtypes comparable to a consensus of stroke experts.
2.Feasibility of Establishing a Stroke Care System through the Acute Stroke Hotline in Busan Metropolitan Area
Ja Hyeon CHO ; Hye-In CHUNG ; Byeol-A YOON ; Dae-Hyun KIM ; Jae-Kwan CHA
Journal of the Korean Neurological Association 2023;41(4):274-280
Background:
The importance of establishing a regional stroke safety net for the treatment of acute stroke is increasingly emphasized. In this study, we analyzed effectiveness of transferring the suspected acute ischemic stroke (AIS) patients through the 1899-0215 hotline system from 119 ambulances and nearby hospitals.
Methods:
From July 2015 to July 2022, we analyzed data from 632 suspected acute stroke patients through the hotline. Furthermore, we investigated the proportion of patients in the target population who were eligible for reperfusion therapy and compared cases transferred by 119 emergency services (EMS) with those transferred from nearby hospitals.
Results:
Six hundred thirty-two suspected acute stroke patients were transferred to our stroke center through the 1899-0215 hotline system. The accuracy of diagnosing acute stroke among transferred patients is 81.0% for 119 EMS and 80.5% for cases transferred from nearby hospitals. Of the 200 patients transferred from hospitals, they were transferred from 47 nearby hospitals with an average transfer distance of 38.2 km and an average transfer time of 65 minutes. Among 291 patients diagnosed with AIS, The onset-to-door time was significantly shorter (p<0.01) for patients transferred by 119 EMS. The proportion of patients who received reperfusion therapy was significantly higher (p<0.01) for those transferred by 119 EMS.
Conclusions
The hotline service will become a useful tool for establishing a regional stroke network in the Busan area, and its effectiveness will be particularly useful for 119 EMS. Measures are needed in the Busan metropolitan region to ensure the speediness of transferring acute stroke patients between hospitals.
3.The First Case of Cutaneous Acanthamoebiasis Caused by Acanthamoeba triangularis in Korea
Mi Soo CHOI ; Na Hye MYONG ; Min SEO ; Sukbin JANG ; Dae Kwan YUN ; Kyujin YEOM ; Dong-Il CHUNG ; Byung Cheol PARK ; Yeonchul HONG ; Myung Hwa KIM
Annals of Dermatology 2023;35(Suppl2):S275-S280
A 62-year-old man with multiple myeloma visited our clinic with multiple painful erythematous to purpuric nodules on his whole body. He received a skin biopsy which showed septal and lobular inflammation with vasculitis, and multiple amoebic organisms were found.Polymerase chain reaction and culture were performed and an Acanthamoeba triangularis infection was diagnosed. This is the first report on cutaneous acanthamoebiasis caused by A. triangularis, suggesting that A. triangularis should be regarded as a clinical pathogen that can cause ocular as well as disseminated infection.
4.Prognostic Implication of Right Ventricle Parameters Measured on Preoperative Cardiac MRI in Patients with Functional Tricuspid Regurgitation
Yura AHN ; Hyun Jung KOO ; Joon-Won KANG ; Won Jin CHOI ; Dae-Hee KIM ; Jong-Min SONG ; Duk-Hyun KANG ; Jae-Kwan SONG ; Joon Bum KIM ; Sung-Ho JUNG ; Suk Jung CHOO ; Cheol Hyun CHUNG ; Jae Won LEE ; Dong Hyun YANG
Korean Journal of Radiology 2021;22(8):1253-1265
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.
5.Valsartan Dosage on Ventriculo-Vascular Coupling Index Dose-Dependency in Heart Failure Patients
Kyung Jin AHN ; Jongwook YU ; Albert Youngwoo JANG ; Dae-Hyeok KIM ; Jun KWAN ; Wook-Jin CHUNG
Yonsei Medical Journal 2021;62(5):391-399
Purpose:
Heart failure (HF) poses significant morbidity and mortality. Recently, the ventriculo-vascular coupling index (VVI) was introduced as an independent prognostic factor reflective of the overall cardiovascular performance index in HF. We aimed to determine the effectiveness of force-titration of valsartan on VVI values in HF patients.
Materials and Methods:
In this multicenter and prospective observational trial, the effect of valsartan was stratified according to dosages [non-ceiling dose (NCD) vs. ceiling dose (CD)] in HF patients with left ventricular ejection fraction (LVEF) <55%. Biochemical studies, including N-terminal pro-B-type natriuretic peptide (NT-proBNP), echocardiography with VVI, the treadmill test, and the activity scale index were assessed at baseline and after 24 weeks of treatment.
Results:
One-hundred thirty-eight patients were force-titrated to either a CD group (n=81) or a NCD group (n=57). The mean age of the study participants was 59 years and 66% were male. After 6 months of follow up, left ventricular mass index (LVMI) values had significantly improved in the CD group but not in the NCD group. Intriguingly, in HF patients with a reduced ejection fraction (HFrEF) (n=52, LVEF <40%), a significant improvement in VVI was only observed in the CD group (from 2.4±0.6 to 1.8±0.5, p<0.001).
Conclusion
CDs of valsartan for 6 months showed better improvement in VVI, as well as LVMI, in patients with HFrEF, compared with NCDs.
6.Prognostic Implication of Right Ventricle Parameters Measured on Preoperative Cardiac MRI in Patients with Functional Tricuspid Regurgitation
Yura AHN ; Hyun Jung KOO ; Joon-Won KANG ; Won Jin CHOI ; Dae-Hee KIM ; Jong-Min SONG ; Duk-Hyun KANG ; Jae-Kwan SONG ; Joon Bum KIM ; Sung-Ho JUNG ; Suk Jung CHOO ; Cheol Hyun CHUNG ; Jae Won LEE ; Dong Hyun YANG
Korean Journal of Radiology 2021;22(8):1253-1265
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.
7.Valsartan Dosage on Ventriculo-Vascular Coupling Index Dose-Dependency in Heart Failure Patients
Kyung Jin AHN ; Jongwook YU ; Albert Youngwoo JANG ; Dae-Hyeok KIM ; Jun KWAN ; Wook-Jin CHUNG
Yonsei Medical Journal 2021;62(5):391-399
Purpose:
Heart failure (HF) poses significant morbidity and mortality. Recently, the ventriculo-vascular coupling index (VVI) was introduced as an independent prognostic factor reflective of the overall cardiovascular performance index in HF. We aimed to determine the effectiveness of force-titration of valsartan on VVI values in HF patients.
Materials and Methods:
In this multicenter and prospective observational trial, the effect of valsartan was stratified according to dosages [non-ceiling dose (NCD) vs. ceiling dose (CD)] in HF patients with left ventricular ejection fraction (LVEF) <55%. Biochemical studies, including N-terminal pro-B-type natriuretic peptide (NT-proBNP), echocardiography with VVI, the treadmill test, and the activity scale index were assessed at baseline and after 24 weeks of treatment.
Results:
One-hundred thirty-eight patients were force-titrated to either a CD group (n=81) or a NCD group (n=57). The mean age of the study participants was 59 years and 66% were male. After 6 months of follow up, left ventricular mass index (LVMI) values had significantly improved in the CD group but not in the NCD group. Intriguingly, in HF patients with a reduced ejection fraction (HFrEF) (n=52, LVEF <40%), a significant improvement in VVI was only observed in the CD group (from 2.4±0.6 to 1.8±0.5, p<0.001).
Conclusion
CDs of valsartan for 6 months showed better improvement in VVI, as well as LVMI, in patients with HFrEF, compared with NCDs.
8.Preoperative Cardiac Computed Tomography Characteristics Associated with Recurrent Aortic Regurgitation after Aortic Valve Re-Implantation
Yura AHN ; Hyun Jung KOO ; Sahmin LEE ; Dae Hee KIM ; Jong Min SONG ; Duk Hyun KANG ; Jae Kwan SONG ; Ho Jin KIM ; Joon Bum KIM ; Sung Ho JUNG ; Suk Jung CHOO ; Cheol Hyun CHUNG ; Jae Won LEE ; Joon Won KANG ; Dong Hyun YANG
Korean Journal of Radiology 2020;21(2):181-191
24 mm² (sensitivity, 76.5%; specificity 64.8%), and the area under the ROC curve (AUC) was 0.72. For ASR(area), the cut-off value was > 1.58 (sensitivity, 76.5%; specificity, 58.0%) and the AUC was 0.64. Multivariable Cox regression showed that ARO > 24 mm² (hazard ratio = 3.79, p = 0.020) was a potential independent parameter for recurrent 3 + AR. ROC for the linear regression model showed that the AUC for both ARO and ASR(area) was 0.73 (95% confidence interval, 0.64–0.81, p < 0.001).CONCLUSION: ARO and ASR(area) detected on preoperative cardiac CT would be potentially helpful for identifying AR patients who may benefit from the David operation.]]>
Aortic Valve Insufficiency
;
Aortic Valve
;
Area Under Curve
;
Echocardiography
;
Humans
;
Linear Models
;
Retrospective Studies
;
ROC Curve
;
Sensitivity and Specificity
;
Tomography, X-Ray Computed
9.Usefulness of Blood Cultures and Radiologic Imaging Studies in the Management of Patients with Community-Acquired Acute Pyelonephritis.
Yeonjae KIM ; Mi Ran SEO ; Seong Jong KIM ; Jieun KIM ; Seong Heon WIE ; Yong Kyun CHO ; Seung Kwan LIM ; Jin Seo LEE ; Ki Tae KWON ; Hyuck LEE ; Hee Jin CHEONG ; Dae Won PARK ; Seong Yeol RYU ; Moon Hyun CHUNG ; Hyunjoo PAI
Infection and Chemotherapy 2017;49(1):22-30
BACKGROUND: The objective of this study was to examine the usefulness of blood cultures and radiologic imaging studies for developing therapeutic strategies in community-acquired acute pyelonephritis (CA-APN) patients. MATERIALS AND METHODS: We prospectively collected the clinical data of CA-APN patients who visited 11 hospitals from March 2010 to February 2011. RESULTS: Positive urine and blood cultures were obtained in 69.3% (568/820) and 42.7% (277/648), respectively, of a total of 827 CA-APN patients. Blood culture identified the urinary pathogen in 60 of 645 (9.3%) patients for whom both urine and blood cultures were performed; the organisms isolated from urine were inconsistent with those from blood in 11 and only blood cultures were positive in 49 patients. Final clinical failure was more common in the bacteremic patients than the non-bacteremic ones (8.0% vs. 2.7%, P = 0.003), as was hospital mortality (3.6% vs. 0.3%, P = 0.003). Likewise, durations of hospitalization and fever were significantly longer. Bacteremia was independent risk factor for mortality (OR 9.290, 1.145-75.392, P = 0.037). With regard to radiologic studies, the detection rate of APN was 84.4% (445/527) by abdominal computed tomography and 40% (72/180) by abdominal ultrasonography. Eighty-one of 683 patients (11.9%) were found to have renal abscess, perinephric abscess, urolithiasis, hydronephorosis/hydroureter or emphysematous cystitis, which could potentially impact on clinical management. Patients with Pitt score ≥ 1, flank pain or azotemia were significantly more likely to have such structural abnormalities. CONCLUSION: Blood cultures are clinically useful for diagnosis of CA-APN, and bacteremia is predictive factor for hospital mortality. Early radiologic imaging studies should be considered for CA-APN patients with Pitt scores ≥1, flank pain or azotemia.
Abscess
;
Azotemia
;
Bacteremia
;
Cystitis
;
Diagnosis
;
Diagnostic Imaging
;
Fever
;
Flank Pain
;
Hospital Mortality
;
Hospitalization
;
Humans
;
Mortality
;
Prospective Studies
;
Pyelonephritis*
;
Risk Factors
;
Ultrasonography
;
Urolithiasis
10.Long-Term Results of Early Surgery versus Conventional Treatment for Infective Endocarditis Trial.
Duk Hyun KANG ; Sahmin LEE ; Yong Jin KIM ; Sung Han KIM ; Dae Hee KIM ; Sung Cheol YUN ; Jong Min SONG ; Cheol Hyun CHUNG ; Jae Kwan SONG ; Jae Won LEE
Korean Circulation Journal 2016;46(6):846-850
BACKGROUND AND OBJECTIVES: Compared with conventional treatment, early surgery significantly reduced the composite end point of all-cause death and embolic events during hospitalization, but long-term data in this area are lacking. This study sought to compare long-term outcomes of early surgery with a conventional treatment strategy in patients with infective endocarditis (IE) and large vegetations. SUBJECTS AND METHODS: The Early Surgery versus Conventional Treatment in Infective Endocarditis (EASE) trial randomly assigned patients with left-sided IE, severe valve disease and large vegetation to early surgery (37 patients) or conventional treatment groups (39 patients). The pre-specified end points were all-cause death, embolic events, recurrence of IE and repeat hospitalizations due to the development of congestive heart failure occurring during follow-up. RESULTS: There were no significant differences between the early surgery and the conventional treatment group in all-cause mortality at 4 years (8.1% and 7.7%, respectively; hazard ratio [HR] 1.04; 95% CI, 0.21 to 5.15; p=0.96). The rate of the composite end point of death from any cause, embolic events or recurrence of IE at 4 years was 8.1% in the early surgery group and 30.8% in the conventional treatment group (HR, 0.22; 95% CI, 0.06-0.78; p=0.02). The estimated actuarial rate of end points at 7 years was significantly lower in the early surgery group than in the conventional treatment group (log-rank p=0.007). CONCLUSION: There was a substantial benefit in having early surgery for patients with IE and large vegetations whose health was sustained up to 7 years, and late clinical outcome after surgery was excellent in survivors of IE. (EASE clinicaltrials.gov identifier: NCT00750373)
Echocardiography
;
Embolism
;
Endocarditis*
;
Follow-Up Studies
;
Heart Failure
;
Heart Valve Diseases
;
Hospitalization
;
Humans
;
Mortality
;
Recurrence
;
Survivors
;
Thoracic Surgery

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