1.Deep Learning for Medical Image Analysis: Applications to Computed Tomography and Magnetic Resonance Imaging.
Kyu Hwan JUNG ; Hyunho PARK ; Woochan HWANG
Hanyang Medical Reviews 2017;37(2):61-70
Recent advances in deep learning have brought many breakthroughs in medical image analysis by providing more robust and consistent tools for the detection, classification and quantification of patterns in medical images. Specifically, analysis of advanced modalities such as computed tomography (CT) and magnetic resonance imaging (MRI) has benefited most from the data-driven nature of deep learning. This is because the need of knowledge and experience-oriented feature engineering process can be circumvented by automatically deriving representative features from the complex high dimensional medical images with respect to the target tasks. In this paper, we will review recent applications of deep learning in the analysis of CT and MR images in a range of tasks and target organs. While most applications are focused on the enhancement of the productivity and accuracy of current diagnostic analysis, we will also introduce some promising applications which will significantly change the current workflow of medical imaging. We will conclude by discussing opportunities and challenges of applying deep learning to advanced imaging and suggest future directions in this domain.
Classification
;
Diagnostic Imaging
;
Efficiency
;
Learning*
;
Magnetic Resonance Imaging*
2.Computed Tomography-Based Preoperative Simulation System for Pedicle Screw Fixation in Spinal Surgery
Woochan WI ; Sang-Min PARK ; Byung-Seok SHIN
Journal of Korean Medical Science 2020;35(18):e125-
Background:
A preoperative planning system facilitates improving surgical outcomes that depend on the experience of the surgeons, thanks to real-time interaction between the system and surgeons. It visualizes intermediate surgical planning results to help surgeons discuss the planning. The purpose of this study was to demonstrate the use of a newly-developed preoperative planning system for surgeons less experienced in pedicle-screw fixation in spinal surgery, especially on patients with anatomical variations.
Methods:
The marching cubes algorithm, a typical surface extraction technique, was applied to computed tomography (CT) images of vertebrae to enable three-dimensional (3D) reconstruction of a spinal mesh. Real-time processing of such data is difficult, as the surface mesh extracted from high-resolution CT data is rough, and the size of the mesh is large. To mitigate these factors, Laplacian smoothing was applied, followed by application of a quadric error metric-based mesh simplification to reduce the mesh size for the level-of-detail (LOD) image. Taubin smoothing was applied to smooth out the rough surface. On a multiplanar reconstruction (MPR) cross-sectional image or a 3D model view, the insertion position and orientation of the pedicle screw were manipulated using a mouse. The results after insertion were then visualized in each image.
Results:
The system was used for pre-planning pedicle-screw fixation in spinal surgery. Using any pointing device such as a mouse, surgeons can manipulate the position and angle of the screws. The pedicle screws were easy to manipulate intuitively on the MPR images, and the accuracy of screw fixation was confirmed on a trajectory view and 3D images. After surgery, CT scans were performed again, and the CT images were checked to ensure that the screws were inserted properly.
Conclusion
The preoperative planning system allows surgeons and students who are not familiar with pedicle-screw fixation to safely undertake surgery following preoperative planning. It also provides opportunities for screw-fixation training and simulation.
3.First Record of the Complete Mitochondrial Genome of a Saprotrophic and Opportunistic Human Pathogenic Fungus, Scopulariopsis brevicaulis
Jongsun PARK ; Woochan KWON ; Seung-Beom HONG ; Kap-Hoon HAN
Mycobiology 2020;48(6):528-531
Scopulariopsis brevicaulis is a widely distributed soil fungus known as a common saprotroph of biodegradation. It is also an opportunistic human pathogen that can produce various secondary metabolites. Here, we report the first complete mitochondrial genome sequence of S. brevicaulis isolated from air in South Korea. Total length of the mitochondrial genome is 28,829 bp and encoded 42 genes (15 protein-coding genes, 2 rRNAs, and 25 tRNAs). Nucleotide sequence of coding region takes over 26.2%, and overall GC content is 27.6%. Phylogenetic trees present that S. brevicaulis is clustered with Lomentospora prolificans with presenting various mitochondrial genome length.
4.First Record of the Complete Mitochondrial Genome of a Saprotrophic and Opportunistic Human Pathogenic Fungus, Scopulariopsis brevicaulis
Jongsun PARK ; Woochan KWON ; Seung-Beom HONG ; Kap-Hoon HAN
Mycobiology 2020;48(6):528-531
Scopulariopsis brevicaulis is a widely distributed soil fungus known as a common saprotroph of biodegradation. It is also an opportunistic human pathogen that can produce various secondary metabolites. Here, we report the first complete mitochondrial genome sequence of S. brevicaulis isolated from air in South Korea. Total length of the mitochondrial genome is 28,829 bp and encoded 42 genes (15 protein-coding genes, 2 rRNAs, and 25 tRNAs). Nucleotide sequence of coding region takes over 26.2%, and overall GC content is 27.6%. Phylogenetic trees present that S. brevicaulis is clustered with Lomentospora prolificans with presenting various mitochondrial genome length.
5.A Successful Repair of Nail Bed Injury with 2-N-butylcyanoacrylate (Histoacryl(TM)): A Case Report.
Eunjung PARK ; Yoonseok JUNG ; Woochan JEON ; Seunghwan SEOL ; Seulki LEE ; Giwoon KIM
Journal of the Korean Society of Emergency Medicine 2012;23(4):567-570
Injury of the nail bed is commonly encountered in the emergency department. Despite the importance of initial management, difficulties such as long duration of operation and need of skill hinder the practice. Tissue repair with tissue adhesives, like 2-N-butylcyanoacrylate (Histoacryl(TM)), is a common replacement for suture repair. Here we describe a case of nail bed injury, which was repaired with Histoacryl(TM), and the method of repair.
Emergencies
;
Nails
;
Sutures
;
Tissue Adhesives
6.A Transfer of Silver Nanoparticles from Pregnant Rat to Offspring.
Yeonjin LEE ; Jonghye CHOI ; Pilje KIM ; Kyunghee CHOI ; Suhyon KIM ; Woochan SHON ; Kwangsik PARK
Toxicological Research 2012;28(3):139-141
Silver nanoparticles (size: 7.9 +/- 0.95 nm, dosage: 250 mg/kg) were orally administered to pregnant rats. At 4 days after parturition, four pups were randomly selected (one pup from one dam) and silver level in liver, kidney, lung and brain was determined by ICP-MS and electron microscope. As results, silver nanoparticles highly accumulated in the tissues of the pups. Silver level in the treated group was 132.4 +/- 43.9 ng/g in the kidney (12.3 fold compared to control group), 37.3 +/- 11.3 ng/g in the liver (7.9 fold), 42.0 +/- 8.6 ng/g in the lung (5.9 fold), and 31.1 +/- 4.3 ng/g in the brain (5.4 fold). This result suggested that the possible transfer of silver nanoparticles from pregnant dams to the fetus through mainly placenta.
Animals
;
Brain
;
Electrons
;
Fetus
;
Kidney
;
Liver
;
Lung
;
Nanoparticles
;
Parturition
;
Placenta
;
Rats
;
Silver
7.Comparison of the Clinical Characteristics of Pediatric Poisoning Patients Who Visited Emergency Department Before and During the COVID-19 Pandemic
Jeewoon PARK ; Woochan JEON ; Yura KO ; Yoo Jin CHOI ; Heewon YANG ; Jisook LEE
Journal of Korean Medical Science 2022;37(47):e337-
Background:
We aimed to investigate changes in the clinical characteristics of pediatric poisoning patients who visited the emergency department (ED) before and during the coronavirus disease 2019 (COVID-19) pandemic.
Methods:
Poisoning cases below age 18 who visited the ED from January 2018 to December 2021 were retrospectively analysed. The study period was then divided into pre-COVID-19 and COVID-19 pandemic to compare poisoning patterns.
Results:
During the study period, 86,153 visits to the pediatric ED had been recorded, with 625 patients being included the final analysis. During the COVID-19 period, the proportion of poisoned patients increased from 0.62% to 0.98%. The average age of the patients was higher in the COVID-19 period, with 53.4% of the cases being intentional (pre-COVID-19, 32.5%; P < 0.001). Moreover, 70.4% of poisoning cases during the COVID-19 period were caused by drugs (pre-COVID-19, 60.6%; P = 0.038). More patients underwent decontamination and laboratory investigation during the COVID-19 period than during the previous period (P= 0.007 and P < 0.001, respectively). The length of ED stay and the proportion of hospitalisation were significantly greater during the COVID-19 period. After analysing accidental poisoning cases, we found that antipyreticsonsteroidal anti-inflammatory drugs and respiratory drugs were more common in the pre-COVID-19 group, whereas iron/vitamins, cardiovascular drugs and hormones were more common in the COVID-19 group. After analysing intentional poisoning cases, we found that 73.6% and 76.4% of the patients in the pre-COVID-19 and COVID-19 group had a history of psychiatric disease, respectively. Although no difference was observed in the frequency of previous first suicide attempts, 19.0% of the patients in the COVID-19 group attempted suicide more than three times.
Conclusion
During the COVID-19 pandemic, intentional poisoning cases, especially in adolescence, increased and were treated more. Many of the patients with intentional poisoning had a history of mental illness or suicide in the past. Therefore, it seems that policy consideration for mentally vulnerable adolescents during this new pandemic period is necessary.
8.Comparison of the Risk Stratification Tools Including the Blatchford Score and the Clinical Rockall for Nonvariceal Upper Gastrointestinal Bleeding in the Emergency Department.
Han You LEE ; Woochan JEON ; Kyung Hwan KIM ; Joon Min PARK ; Hyunjong KIM ; Junseok PARK ; Dong Wun SHIN ; Hoon KIM
Journal of the Korean Society of Emergency Medicine 2014;25(5):611-616
PURPOSE: Upper gastrointestinal bleeding (UGIB) is a common medical emergency condition in the emergency department (ED). Patients with UGIB show a wide range of clinical severity, from mild bleeding to death. The objective of this study was to evaluate methods for risk stratification of active UGIB in the ED. METHODS: We retrospectively reviewed patients with UGIB who were admitted to the ED of a tertiary care, university-affiliated hospital center from January 2011 to December 2011. Our study subjects were patients over 20 years old who complained of symptoms and signs of gastrointestinal tract bleeding and underwent endoscopic gastroduodenoscopy (EGD) evaluation. However, patients diagnosed with variceal gastrointestinal bleeding, disseminated malignancy, coagulopathy, and lower gastrointestinal bleeding and patients who did not undergo EGD within 6 hours were excluded. The Blatchford score and the clinical Rockall score were calculated for the enrolled patients. In cases where the value of each score was greater than 0, the scores were considered high risk. Active UGIB was defined as a symptom of patients who underwent emergency endoscopic intervention such as ligation or sclerotherapy. We compared the proportions of patients identified as high risk using chi tests. The areas under the receiver operating characteristic (AUROC) curve for detection of patients requiring emergency endoscopic intervention were calculated for both the Blatchford score and the clinical Rockall score. RESULTS: The numbers of patients with high risk according to the Blatchford score and the clinical Rockall were 220 (93.6%) and 192 (81.7%) of 235 patients, respectively. The number of patients with active UGIB was 96 (40.9%) of 235 patients. The sensitivity and specificity of risk stratification based on the Blatchford score was 100% (96/96) and 10.8% (15/139) (p=0.001), respectively, while those based on the clinical Rockall score were 80.2% (77/96) and 17.3% (24/139) (p>0.05). The AUROC curves of the Blatchford score and the clinical Rockall score were 0.617 (95% CI; 0.546-0.688) and 0.495 (95% CI; 0.420-0.571), respectively. CONCLUSION: The Blatchford score could be more useful as a risk stratification tool than the clinical Rockall score for active UGIB patients in the ED. The Blatchford score would be preferable as a clinical tool that can discriminate patients who need emergency endoscopic intervention for control of UGIB.
Emergencies
;
Emergency Service, Hospital*
;
Endoscopy
;
Gastrointestinal Hemorrhage
;
Gastrointestinal Tract
;
Hemorrhage*
;
Humans
;
Ligation
;
Retrospective Studies
;
ROC Curve
;
Sclerotherapy
;
Sensitivity and Specificity
;
Tertiary Healthcare
9.Trends in Korean Pediatric Poisoning Patients: Retrospective Analysis of National Emergency Department Information System.
Kyeongjae LEE ; Kyung Hwan KIM ; Dong Wun SHIN ; Junseok PARK ; Hoon KIM ; Woochan JEON ; Joon Min PARK ; Hyunjong KIM
Journal of The Korean Society of Clinical Toxicology 2017;15(2):69-78
PURPOSE: This study reports the clinical features of infant, child, school aged and adolescent patients treated for acute poisoning in nationwide emergency departments (EDs). METHODS: We retrospectively analyzed clinical data pertaining to patients under 19 years of age who were treated for acute poisoning in nationwide EDs from 2013 to 2015. The data were collected by the National Emergency Department Information System (NEDIS). All patients were divided into three groups: ‘Infant and child group’ (0 to 5 years), ‘school age group’ (6 to 12 years) and ‘adolescent group’ (13 to 18 years). General characteristics, Korea Standard Classification of Disease 7(th) (KCD-7) codes and results of care were collected. RESULTS: There were 14,500 pediatric poisoning cases during the study period. The distribution of patient age was bimodal with two peaks among infant, child and adolescent group. The proportion of alert mentality at the ED visit of the infant and child group was 99.3%, while that of the adolescent group was 86.4%. The proportion of intentional intoxication was higher in the adolescent group (40.7%) than other age groups. Among children less than 13 years of age, various poisonous substances and therapeutic drugs were common. CONCLUSION: There were some clinical differences in acute poisoning patients between age groups. It is necessary to establish a preventive plan considering characteristics by age. Since the KCD-7 code has limitations in analyzing the characteristics of poisoning patients, it is necessary to consider the registration system of poisoning patients.
Adolescent
;
Child
;
Classification
;
Emergencies*
;
Emergency Service, Hospital*
;
Humans
;
Infant
;
Information Systems*
;
Korea
;
Pediatrics
;
Poisoning*
;
Retrospective Studies*
10.Playground Equipment Related Injuries in Preschool-Aged Children: Emergency Department-based Injury In-depth Surveillance.
Sohyun BAE ; Ji Sook LEE ; Kyung Hwan KIM ; Junseok PARK ; Dong Wun SHIN ; Hyunjong KIM ; Joon Min PARK ; Hoon KIM ; Woochan JEON
Journal of Korean Medical Science 2017;32(3):534-541
In this study, we investigated playground equipment related injuries in preschool-aged children. This was a retrospective observational study using Emergency Department based Injury In-depth Surveillance, (2011–2014). We included the preschool-aged children with playground equipment related injuries. We surveyed the mechanism and incidence of injuries, and estimated the odds ratio (OR) of traumatic brain injury (TBI) and upper/lower extremities fracture. There were 6,110 patients, mean age was 4.14 ± 1.95 years old. Slide and swing related injuries were 2,475 (40.5%) and 1,102 (18.0%). Fall down (48.5%) was the most common mechanism. The OR of TBI in children 0–2 years old was 1.88 times higher than children 3–7 years old, and in swing was 4.72 (OR, 4.72; 95% confidence interval [CI], 2.37–9.40) times higher than seesaw. The OR of upper extremity fracture in children 3–7 years old was 3.07 times higher than children 0–2 years old, and in climbing was 2.03 (OR, 2.03; 95% CI, 1.63–2.52) times higher than swing. The OR of lower extremity fractures in horizontal bars, tightropes, and trampolines was 2.95 (OR, 2.95; 95% CI, 1.55–5.61) times higher than swing. The most common mechanism and playground equipment were fall down and slide. TBI was associated to younger children (0–2 years old) and swing. Fracture of upper extremities was associated to older children (3–7 years old) and climbing. Fracture of lower extremities was associated to others such as horizontal bars, tightropes, and trampolines.
Brain Injuries
;
Child*
;
Child, Preschool
;
Emergencies*
;
Emergency Service, Hospital
;
Extremities
;
Fractures, Bone
;
Humans
;
Incidence
;
Lower Extremity
;
Observational Study
;
Odds Ratio
;
Play and Playthings
;
Retrospective Studies
;
Upper Extremity
;
Wounds and Injuries