• Current Optics and Photonics
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• v.7 no.4
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• pp.398-407
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• 2023

We explored a method to evaluate imaging performance for the optimal assembly of an endoscopic miniature lens and a sensor constituting an imaging module at the distal end of gastrointestinal endoscopy. For the assembly of the imaging module, the image sensor was precisely located at the focal plane when collimated light passed through the endoscopic lens. As another method, the distance between the lens and sensor was adjusted to obtain the highest focus index from images measured the star chart of the International Organization for Standardization (ISO) standard at various positions. We analyzed the slanted-edge modulation transfer function (MTF), corresponding depth of field, and number of line pairs for MTF 50% and 20% at each working distance within the range of 5-100 mm for imaging modules assembled in different ways. Assembly conditions of the imaging module with better MTF performance were defined for each working distance range of 5-30 mm and 30-100 mm, respectively. In addition to the MTF performance, the focus index of each assembled module was also compared. In summary, we examined the performance of imaging modules assembled with different methods within the suggested working distance and tried to establish the optimal assembly protocol.

• 대한위암학회:학술대회논문집
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• 2002.10a
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• pp.24-33
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• 2002

Clinical application of positron emission tomography (PET) is rapidly increasing for the detection and staging of cancer at whole-body studies performed with the glucose analogue tracer 2-[fluorine-18]fluoro-2-deoxy-D-glucose (FDG). Although FDG PET cannot match the anatomic resolution of conventional imaging techniques in gastrointestinal and abdominal organs, it is particularly useful for identification and characterization of whole body at the same time. FDG PET can show foci of metastatic disease that may not be apparent at conventional anatomic imaging and can aid in the characterization of indeterminate soft-tissue masses. Most gastrointestinal cancer need to surgical management. FDG PET can improve the selection of patients for surgical treatment and thereby reduce the morbidity and mortality associated with inappropriate surgery. FDG PET is also useful for the early detection of recurrence and the monitoring of therapeutic effect. The gastrointestinal cancers, such as gastroeso-phageal cancer, colorectal cancer, liver cancer and pancreatic cancer, are common malignancies in Korea. PET is one of the most promising and useful methodology for the management of gastric cancer as well as other gastrointestinal cancers.

• Journal of Gastric Cancer
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• v.2 no.4
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• pp.184-190
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• 2002

Clinical application of positron emission tomography (PET) is rapidly increasing for the detection and staging of cancer at whole-body studies performed with the glucose analogue tracer 2-[fluorine-18]fluoro-2-deoxy-D-glucose (FDG). Although FDG PET cannot match the anatomic resolution of conventional imaging techniques in gastrointestinal and abdominal organs, it is particularly useful for identification and characterization of whole body at the same time. FDG PET can show foci of metastatic disease that may not be apparent at conventional anatomic imaging and can aid in the characterization of indeterminate soft-tissue masses. Most gastrointestinal cancer need to surgical management. FDG PET can improve the selection of patients for surgical treatment and thereby reduce the morbidity and mortality associated with inappropriate surgery. FDG PET is also useful for the early detection of recurrence and the monitoring of therapeutic effect. The gastrointestinal cancers, such as gastroesophageal cancer, colorectal cancer, liver cancer and pancreatic cancer, are common malignancies in Korea. PET is one of the most promising and useful methodology for the management of gastric cancer as well as other gastrointestinal cancers.

• Journal of the Korean Society of Radiology
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• v.81 no.4
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• pp.770-793
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• 2020

Newborn gastrointestinal tract emergency diseases include various disorders that occur anywhere along the digestive tract. Most of them are congenital malformations, not acquired diseases. Many of them cannot be confirmed on prenatal examination, and consequently, postnatal evaluation is required. Unlike adults, in newborn babies, detailed evaluations with computed tomography (CT) and magnetic resonance imaging (MRI) are often limited, so making the diagnosis based on early abdominal radiography is most important. Therefore, it is necessary to be familiar with the radiologic findings that may be seen on imaging studies. In addition, it is important to understand abdominal ultrasound and fluoroscopy findings, which can be used in addition to simple radiography and indications that can be used for further diagnosis and appropriate treatment. Therefore, this study describes and organizes the various imaging findings that may occur in neonatal gastrointestinal emergencies.

• Korean Journal of Radiology
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• v.23 no.1
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• pp.124-138
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• 2022

Gastrointestinal (GI) emergencies in neonates and infants encompass from the beginning to the end of the GI tract. Both congenital and acquired conditions can cause various GI emergencies in neonates and infants. Given the overlapping or nonspecific clinical findings of many different neonatal and infantile GI emergencies and the unique characteristics of this age group, appropriate imaging is key to accurate and timely diagnosis while avoiding unnecessary radiation hazard and medical costs. In this paper, we discuss the radiological findings of essential neonatal and infantile GI emergencies, including esophageal atresia and tracheoesophageal fistula, hypertrophic pyloric stenosis, duodenal atresia, malrotation, midgut volvulus for upper GI emergencies, and jejunoileal atresia, meconium ileus, meconium plug syndrome, meconium peritonitis, Hirschsprung disease, anorectal malformation, necrotizing enterocolitis, and intussusception for lower GI emergencies.

• Journal of the Korean Society of Radiology
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• v.84 no.5
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• pp.1169-1175
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• 2023

Clear cell sarcoma-like tumor of the gastrointestinal tract (CCSLTGT) is a rare malignant mesenchymal tumor of the gastrointestinal (GI) tract with a high probability of local recurrence and distant metastasis in young adults. To the best of our knowledge, only seven case reports have described the imaging findings of a CCSLTGT originating from in the small intestine in English literatures so far. Therefore, we report the imaging findings of a CCSLTGT that occurred in the small intestine of a 22-year-old female and summarize the imaging findings of the previous reports.

• The Journal of Internal Korean Medicine
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• v.39 no.4
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• pp.794-801
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• 2018

Objectives: These cases report the benefits of administration of Banhasasim-tang extracts or decoctions to patients with functional gastrointestinal disorders after motor vehicle accidents. Methods: The patients were treated with Banhasasim-tang extract or decoction three times daily. History-taking and imaging tests were used to differentiate other diseases. We evaluated the patients using the Gastrointestinal Symptom Rating Scale (GSRS), which is used to assess overall gastrointestinal symptoms. Results: Treatment with herbal medicine resulted in a decrease in the patients' complaints of symptoms. The GSRS scale showed improvement in all four cases. Conclusions: Banhasasim-tang, regardless of its form, has beneficial effects in patients with functional gastrointestinal disorders after motor vehicle accidents.

• Clinical Endoscopy
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• v.55 no.5
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• pp.594-604
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• 2022

Over the past decade, technological advances in deep learning have led to the introduction of artificial intelligence (AI) in medical imaging. The most commonly used structure in image recognition is the convolutional neural network, which mimics the action of the human visual cortex. The applications of AI in gastrointestinal endoscopy are diverse. Computer-aided diagnosis has achieved remarkable outcomes with recent improvements in machine-learning techniques and advances in computer performance. Despite some hurdles, the implementation of AI-assisted clinical practice is expected to aid endoscopists in real-time decision-making. In this summary, we reviewed state-of-the-art AI in the field of gastrointestinal endoscopy and offered a practical guide for building a learning image dataset for algorithm development.

• Clinical Endoscopy
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• v.56 no.4
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• pp.455-456
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• 2023

• Journal of the Korean Society of Radiology
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• v.84 no.3
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• pp.520-535
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• 2023

Gastrointestinal (GI) bleeding is not a single disease but a symptom and clinical manifestation of a broad spectrum of conditions in the GI tract. According to its clinical presentation, GI bleeding can be classified into overt, occult, and obscure types. Additionally, it can be divided into upper and lower GI bleeding based on the Treitz ligament. Variable disease entities, including vascular lesions, polyps, neoplasms, inflammation such as Crohn's disease, and heterotopic pancreatic or gastric tissue, can cause GI bleeding. CT and conventional angiographies and nuclear scintigraphy are all radiologic imaging modalities that can be used to evaluate overt bleeding. For the work-up of occult GI bleeding, CT enterography (CTE) can be the first imaging modality. For CTE, an adequate bowel distention is critical for obtaining acceptable diagnostic performance as well as minimizing false positives and negatives. Meckel's scintigraphy can be complementarily useful in cases where the diagnosis of CTE is suboptimal. For the evaluation of obscured GI bleeding, various imaging modalities can be used based on clinical status and providers' preferences.