• 정보처리학회논문지:소프트웨어 및 데이터공학
• /
• 제9권3호
• /
• pp.101-108
• /
• 2020

최근의 영상 처리 분야는 딥러닝 기법들의 성능이 입증됨에 따라 다양한 분야에서 이와 같은 기법들을 활용해 영상에 대한 분류, 분석, 검출 등을 수행하려는 시도가 활발하다. 그중에서도 의료 진단 보조 역할을 할 수 있는 의료 영상 분석 소프트웨어에 대한 기대가 증가하고 있는데, 본 연구에서는 데이터 셋이 방대하고 판단에 시간이 오래 걸리는 캡슐내시경 영상에 주목하였다. 본 논문의 목적은 캡슐내시경 영상의 판독에서 모든 환자에 대해 공통으로 수행되고, 판독하는 데 많은 시간을 차지하는 위장관 랜드마크를 구별하고 위장관 교차점을 추정하는 것이다. 이를 위해, 위장관 랜드마크를 식별할 수 있는 CNN 학습 모델을 설계하였으며, 이를 이용하여 결괏값을 필터링해 위장관 교차점을 추정하였다. 무작위로 환자 데이터를 샘플링한 모델을 이용해서 나온 결과를 필터링 후에 위장관 교차점을 추정하였을 때, 88% 환자는 위장에서 소장으로 변화하는 위장관 교차점(유문판) 의심 구역 안에 들어왔으며, 소장에서 대장으로 변화하는 위장관 교차점(회맹판)의 경우 100% 환자가 위장관 교차점 의심 구역 안에 들어온 것을 확인할 수 있었다. 100프레임 범위로 위장관 교차점 의심 구역을 찾을 수 있었으며, 판독자가 초당 10프레임의 속도로 판독을 진행한다면 10초안에 위장관 교차점을 찾아낼 수 있다.

• Pediatric Gastroenterology, Hepatology & Nutrition
• /
• 제10권1호
• /
• pp.20-27
• /
• 2007

목 적: 소아에서 위장관 내시경 시술이 비약적으로 늘고 있고 내시경 기술과 적응증이 확대되고 있으나 이러한 변화를 분석한 보고가 매우 드물어 한 병원에서 최근 시행된 위장관 내시경 검사의 경험을 분석함으로써 소아에서 위장관 내시경 검사의 유용성과 안정성을 살펴보았다. 방 법: 2001년 1월부터 2005년 6월까지 4년 6개월 동안 부산대학교병원 소아과에서 위장관 내시경 검사를 받았던 1,040명의 환자를 대상으로 병력지 분석을 통한 후향적 연구를 시행하였다. 총 1,040예의 내시경 검사가 시행되었고 상부 위장관 검사가 840예, 하부 위장관 검사가 200예였다. 결 과: 환자의 남녀비는 1.25:1이었다. 환자의 평균 연령이 $8.5{\pm}2.1$세였고 신생아와 영아가 6.0%를 차지하였으며 5세 이하가 절반을 차지하였다. 상부 위장관(UGI) 및 하부 위장관(LGI)의 진단적 내시경 검사는 각각 634명과 163명에서 시행되었다. UGI 검사의 주된 적응증은 복통(38.8%), 구토(19.4%), 이물(17.7%), 토혈(10.3%) 등이었고, LGI 검사의 주된 적응증은 혈변(56.0%), 복통(27.5%), 설사(3.0%) 등이었다. UGI 치료적 내시경술의 종류로는 이물 제거(148예), 식도 협착에 대한 풍선 확장술(27예), 경피 내시경하 위루술(15예), 내시경적 식도 정맥류 결찰술(3예)이 있었다. LGI 치료적 내시경술은 37명에서 시행되었으며 용종절제술이 34예, 아르곤 플라즈마 응고술이 3예였다. 내시경술의 합병증으로 식도, 위, 대장의 천공이 각각 1예씩 있었고, 호흡 곤란이 4예에서 발생하였다. 결 론: 위장관 내시경 검사는 소아의 위장관 질환의 진단과 치료에 중요한 역할을 하였으며, 전 연령에서 비교적 안전하게 시행되었다. 나이 어린 환자에서의 검사 빈도와 하부 위장관 검사, 다양한 종류의 치료적 내시경 시술이 늘고 있음을 알 수 있었다.

• Asian Pacific Journal of Cancer Prevention
• /
• 제13권6호
• /
• pp.2721-2728
• /
• 2012

Background: There are limited data evaluating the cost-effectiveness of gastric cancer screening using endoscopy or upper gastrointestinal x-ray in the general population. Objective: To evaluate the cost-effectiveness of population-based screening for gastric cancer in South Korea by decision analysis. Methods: A time-dependent Markov model for gastric cancer was constructed for healthy adults 30 years of age and older, and a deterministic sensitivity analysis was performed. Cost-utility analysis with multiple strategies was conducted to compare the costs and effects of 13 different screening alternatives with respect to the following eligibility criteria: age at the beginning of screening, screening interval, and screening method. The main outcome measurement was the incremental cost-effectiveness ratio. Results: The results revealed that annual endoscopic screening from ages 50-80 was the most cost-effective for the male population. In the females, biennial endoscopy screening from ages 50-80 was calculated as the most cost-effective strategy among the 12 screening alternatives. The most cost-effective screening strategy may be adjustable according to the screening costs and the distribution of cancer stage at screening. The limitation was that effectiveness data were obtained from published sources. Conclusions: Using the threshold of $19,162 per quality-adjusted life year on the basis of the Korean gross domestic product (2008), as suggested by the World Health Organization, endoscopic gastric cancer screening starting at the age of 50 years was highly cost-effective in the Korean population. The national recommendation for gastric cancer screening should consider the starting age of screening, the screening interval, and the screening modality.

• Journal of Digestive Cancer Research
• /
• 제10권2호
• /
• pp.56-64
• /
• 2022

Narrow-band imaging (NBI) is the most widely used image-enhanced endoscopic technique. The superficial microanatomy of gastric mucosa can be visualized when used with a magnifying endoscopy with narrow-band imaging (ME-NBI). The diagnostic criteria for early gastric cancer (EGC), using the classification system for microvascular and microsurface pattern of ME-NBI, have been developed, and their usefulness has been proven in the differential diagnosis of small depressed cancer from focal gastritis and in lateral extent delineation of EGC. Some studies reported on the prediction of histologic differentiation and invasion depth of gastric cancer using ME-NBI; however, its application is limited in clinical practice, and further well-designed studies are necessary. Clinicians should understand the ME-NBI classification system and acquire appropriate diagnostic skills through various experiences and training to improve the quality of endoscopy for EGC diagnosis.

• Journal of Yeungnam Medical Science
• /
• 제33권2호
• /
• pp.146-149
• /
• 2016

Heterotopic bone formation in the gastrointestinal tract is a rare phenomenon. Most reported cases were associated with benign and malignant neoplasms, except for a case in which heterotopic bone formation was found in a patient with Barrett's esophagus. The exact pathogenesis of the disease has not yet been established. However, most heterotopic bones found in the gastrointestinal tract were associated with mucinproducing tumors of the appendix, colon, and rectum. Inflammation may also play a role in osseous metaplasia in a case with bone formation at the base of an ulcer in Barrett's esophagus. Here, we report on a patient with heterotopic bone formation in normal gastric cardiac mucosa. A 50-year-old female visited our hospital for a routine health examination. She had no gastrointestinal symptoms, and her physical examination, blood test, X-ray, urine, and stool examination results were normal. A 0.3 cm sized polypoid lesion located just below the squamocolumnar junction was observed on upper gastrointestinal endoscopy. A piece of biopsy was taken. Histologically, a lamella bone trabecula and chronic inflammatory cells were observed in the gastric cardiac mucosa. The follow-up endoscopy performed one month later showed no residual lesion.

• Advances in pediatric surgery
• /
• 제20권1호
• /
• pp.12-16
• /
• 2014

Foreign body ingestion is a common problem among paediatric populations. Most of the ingested foreign bodies spontaneously pass through the gastrointestinal tract, but approximately less then 10% of them remain without being discharged, and trigger complications. Therefore, proper evaluation and treatment according to the situation is required. In this study, clinical progress and complications were analyzed according to the clinical features and treatment in children who ingested foreign bodies. Among pediatric patients under 18 who were admitted to Chonnam National University Hospital after ingesting foreign bodies between January 2008 to June 2012, only the patients who had their foreign body in the gastrointestinal tract were included in this study. Based on medical records, age, type of foreign body, time spent till admission, and whether the endoscopy was done or not, complication were researched retrospectively. According to symptoms and plain abdomen X-ray findings, treatment was chosen and conducted among endoscopy, observation and emergency operation. Among 273 patients, 9 (3.3%) of them had surgical removal. Seven (2.6%) of them had an emergency operation on the day of admission, and the rest 2 (0.7%) had operation during observation. Removal through initial endoscopic approach was tried in 157 (57.5%) patients. Eleven (70.8%) of them had their foreign body removed at the initial trial, and 5 (4.9%) of them at the second trial. Among 109, who were on observation status, 9 (8.3%) of them needed endoscopic removal, and 2 (1.8%) of them suffered from surgical removal. It is thought to be better to approach slowly considering the type, size and symptoms in foreign body ingestion of pediatric patients, rather than immediate and invasive removal.

• Clinical Endoscopy
• /
• 제51권6호
• /
• pp.552-557
• /
• 2018

Although colonoscopy was originally a diagnostic imaging procedure, it has now expanded to include an increasing range of therapeutic interventions. These procedures require precise maneuvers of instruments, execution of force, efficient transmission of force from the operator to the point of application, and sufficient dexterity in the mobilization of endoscopic surgical instruments. The conventional endoscope is not designed to support technically demanding endoscopic procedures. In case of colonoscopy, the tortuous anatomy of the colon makes inserting, moving, and orientating the endoscope difficult. Exerting excessive pressure can cause looping of the endoscope, pain to the patient, and even perforation of the colon. To mitigate the technical constraints, numerous technically enhanced systems have been developed to enable better control of instruments and precise delivery of force in the execution of surgical tasks such as apposing, grasping, traction, counter-traction, and cutting of tissues. Among the recent developments are highly dexterous robotic master and slave systems, computer-assisted or robotically enhanced conventional endoscopes, and autonomously driven locomotion devices that can effortlessly traverse the colon. Developments in endoscopic instrumentations have overcome technical barriers and opened new horizons for further advancements in therapeutic interventions. This review describes examples of some of these systems in the context of their applications to advanced therapeutic colonoscopy.

• Asian Pacific Journal of Cancer Prevention
• /
• 제16권8호
• /
• pp.3591-3592
• /
• 2015

Endoscopy has been increasingly used in clinical practice and as a standardized examination procedure for gastrointestinal diseases. However, only a few studies on endoscopic screening for evaluating mortality reduction from gastric cancer have been carried out. Even if a high detection rate is obtained in clinical practice, such a rate cannot be directly accepted as evidence providing the effectiveness of cancer screening. Endoscopic screening for gastric cancer is not an exception of possibility to detect overdiagnosis. If detection rate is used for the evaluation of the effectiveness of cancer screening, the possibility of overestimating the effectiveness of cancer screening cannot be ruled out. To avoid the effect of overdiagnosis and confirm the effectiveness of endoscopic screening, mortality reduction from gastric cancer must be carefully evaluated by conducting reliable studies. The burden of gastric cancer remains real and this cannot be ignored in Eastern Asian countries. To determine the best available method for gastric cancer screening, evaluation of its effectiveness is a must. Endoscopic screening for gastric cancer has shown promising results, and thus deserves further comprehensive evaluation to reliably confirm its effectiveness and how its optimal use can be strategically promoted.

• Clinical Endoscopy
• /
• 제51권6호
• /
• pp.596-599
• /
• 2018

An 89-year-old man was referred to our hospital for treatment of hepatolithiasis causing recurrent cholangitis. He had undergone a prior Whipple procedure. Computed tomography demonstrated left-sided hepatolithiasis. First, we conducted peroral direct cholangioscopy (PDCS) using an ultraslim endoscope. Although PDCS was successfully conducted, it was unsuccessful in removing all the stones. The stones located in the B2 segment were difficult to remove because the endoscope could not be inserted deeply into this segment due to the small size of the intrahepatic bile duct. Next, we substituted the endoscope with an upper gastrointestinal endoscope. After positioning the endoscope, the SpyGlass digital system (SPY-DS) was successfully inserted deep into the B2 segment. Upon visualizing the residual stones, we conducted SPY-DS-guided electrohydraulic lithotripsy. The stones were disintegrated and completely removed. In cases of PDCS failure, a treatment strategy using the SPY-DS can be considered for patients with hepatolithiasis after a Whipple procedure.

• Current Optics and Photonics
• /
• 제7권4호
• /
• pp.398-407
• /
• 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.