품질 관리 및 분류 성능 향상을 위한 흉부 방사선 이미지 검사 네트워크

학위논문(석사) -- 서울대학교대학원 : 데이터사이언스대학원 데이터사이언스학과, 2022.2. 이승근.Predicting the presence of diseases in chest radiographs using deep learning methods is one of the most common medical imaging tasks. Recently, the performances of the state-of-the-art models outperformed the radiologists for some diseases. However, there are still many chest radiographs that even those state-of-the-art models cannot correctly classify. Some chest radiographs are either too difficult to classify or contain elements that are confusing to the models. This paper proposes a chest radiograph inspection network (CRI-Net), a deep learning method that quantifies how well or poorly a disease classification model will classify chest radiographs. Large dataset experiments showed that the method can perform quality control on chest radiographs and further can enhance the AUROC of the disease classification predictions for some diseases.딥러닝 방법론을 사용해 흉부 방사선 사진에서 질병의 존재를 예측하는 것은 가장 일반적인 의료 영상 작업 중 하나다. 최신 모델들은 일부 질병 분류에 대해 방사선 전문의를 능가할 정도로 발전했다. 그러나 이러한 모델로도 정확하게 분류할 수 없는 흉부 방사선 사진은 여전히 많다. 일부 흉부 방사선 사진은 분류하기에 너무 어렵거나 모델에게 혼동을 주는 요소를 갖고 있다. 본 논문은 질병 분류 모델이 흉부 방사선 사진을 얼마나 잘, 혹은 잘못 분류할지를 정량화하는 딥러닝 방법론인 흉부 방사선 사진 검사 네트워크(CRI-Net)를 제안한다. 대용량 데이터로 실험한 결과, 해당 방법론이 일부 질병에 대해 흉부 방사선 사진에 대한 품질 관리를 수행할 수 있고 질병 분류 예측 AUROC를 강화할 수 있음을 확인했다.Abstract i Contents ii List of Figures iv List of Tables v 1 Introduction 1 2 Related Works 3 3 Methods 5 3.1 Data 5 3.2 Disease Classification Model 5 3.3 Cross-Validation 7 3.4 DifficultyLabeling 7 3.5 CRI-Net 10 4 Experiments 12 4.1 Setup 12 4.2 Quality Control 12 4.3 AUROC Performance Boosting 13 5 Results 16 5.1 Quality Control 16 5.2 AUROC Performance Boosting 18 6 Discussion 20 Bibliography 22 초 록 24석

Hepatitis C Virus and Hepatocarcinogenesis

Hepatitis C virus (HCV) is an RNA virus that is unable to integrate into the host genome. However, its proteins interact with various host proteins and induce host responses. The oncogenic process of HCV infection is slow and insidious and probably requires multiple steps of genetic and epigenetic alterations, the activation of cellular oncogenes, the inactivation of tumor suppressor genes, and dysregulation of multiple signal transduction pathways. Stellate cells may transdifferentiate into progenitor cells and possibly be linked to the development of hepatocellular carcinoma (HCC). Viral proteins also have been implicated in several cellular signal transduction pathways that affect cell survival, proliferation, migration and transformation. Current advances in gene expression profile and selective messenger RNA analysis have improved approach to the pathogenesis of HCC. The heterogeneity of genetic events observed in HCV-related HCCs has suggested that complex mechanisms underlie malignant transformation induced by HCV infection. Considering the complexity and heterogeneity of HCCs of both etiological and genetic aspects, further molecular classification is required and an understanding of these molecular complexities may provide the opportunity for effective chemoprevention and personalized therapy for HCV-related HCC patients in the future. In this review, we summarize the current knowledge of the mechanisms of hepatocarcinogenesis induced by HCV infection

Changes in medical care due to the absence of internal medicine physicians in emergency departments

Objective Especially in emergency departments (EDs), a lack of internal medicine (IM) residents in charge causes difficulties in medical care and ED overcrowding. Thus, protocols without IM residents in EDs is needed. This study aimed to investigate changes in medical care when emergency medicine residents replaced the roles of IM residents. Methods This study was conducted at a single-site ED of a university medical center. The study group contained patients admitted to the IM department between September and December 2015, during which IM residents were absent in the ED. The control group contained patients admitted to the IM department between September and December 2014, during which IM residents were present in the ED. Changes in medical care between the presence and absence of IM residents in the ED were studied by comparing admission rates from the ED, length of ED stay, duration of hospitalization, and concordance of diagnoses between admission and discharge by the IM department. Results The study group contained 2,341 patients; the control group contained 2,215 patients. Admission rates from the ED increased by 53.4% (95% confidence interval [CI], P<0.001); lengths of stay decreased by 15.1% (95% CI, P<0.001); and durations of hospitalization in the pulmonology department decreased by 38.4% (95% CI, P=0.001). Concordance of diagnoses between admission and discharge decreased by 14.2% in the cardiology department (95% CI, P=0.021). Conclusion Lengths of stay were reduced without critical declines in diagnostic concordance rates when emergency medicine physicians, instead of IM residents in the ED, decided upon admissions of IM patients