• Journal of the Korean Society of Radiology
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• v.83 no.1
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• pp.70-83
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• 2022

Acute coronary syndrome (ACS) is mainly caused by atherosclerotic coronary artery disease (CAD); however, it can also occur in patients with non-atherosclerotic CAD. Conventional coronary angiography only shows the lumen of arteries, indicating the presence of stenosis or dilatation. Thus, it has limited value in evaluating the coronary artery wall and offers low specificity for diagnosing CAD. Coronary CT angiography provides additional information, including the depiction of the concerned vessel and the aorta, as well as the pulmonary artery, which permits the diagnosis of non-atherosclerotic CAD and the differentiation of various causes of the disease. In this review, we present the pathophysiology and CT imaging features of non-atherosclerotic CAD.

• Journal of the Korean Society of Radiology
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• v.82 no.3
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• pp.715-720
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• 2021

Transurethral resection (TUR) is the gold standard treatment of non-muscle invasive bladder cancers. Recurrence occurs in approximately half of the patients with bladder cancer after initial TUR. Most recurrent bladder cancers present as polypoid masses with intraluminal growth originating from the mucosa. To the best of our knowledge, there has been no report on imaging findings of recurrent bladder cancers located within the subepithelial and intramural layers. Recurrent cancers within the intramural layer are difficult to detect with cystoscopy; they are also difficult to remove surgically. Imaging studies reveal the most important indicators for diagnosing subepithelial recurrent cancers. Here, we present a rare case of a recurrent bladder cancer within the subepithelial layer detected on imaging.

• Journal of the Korea Society of Computer and Information
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• v.4 no.2
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• pp.80-87
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• 1999

We propose the various Telemedicine applications using collaborative PACS environment. Traditionally, almost all medical images have been printed on radiological films. These films are expensive to produce and easy to misplace and usually only one copy exists, thus limiting the number of persons who have simultaneous access to the images. But the merit of this system including PACS(Picture Archiving and Communications System ) is very many which are small depository, low maintenance expense, good efficience(storage, speed) and good flexibility but the development costs is higher. This research has been done creating multimedia-based Telemedicine system for home PCs in network environment. Most of Telemedicine used hardware and exclusive line of high cost as CATV broadcasting technique. But this system will contribute to change the Home-PC for better use of collaborations among doctor and patients through various modes of interactions in cyberspace.

• Journal of the Korean Society of Radiology
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• v.82 no.5
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• pp.1196-1206
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• 2021

Purpose To construct a standard dataset of contrast-enhanced CT images of liver tumors to test the performance and safety of artificial intelligence (AI)-based algorithms for clinical decision support systems (CDSSs). Materials and Methods A consensus group of medical experts in gastrointestinal radiology from four national tertiary institutions discussed the conditions to be included in a standard dataset. Seventy-five cases of hepatocellular carcinoma, 75 cases of metastasis, and 30-50 cases of benign lesions were retrieved from each institution, and the final dataset consisted of 300 cases of hepatocellular carcinoma, 300 cases of metastasis, and 183 cases of benign lesions. Only pathologically confirmed cases of hepatocellular carcinomas and metastases were enrolled. The medical experts retrieved the medical records of the patients and manually labeled the CT images. The CT images were saved as Digital Imaging and Communications in Medicine (DICOM) files. Results The medical experts in gastrointestinal radiology constructed the standard dataset of contrast-enhanced CT images for 783 cases of liver tumors. The performance and safety of the AI algorithm can be evaluated by calculating the sensitivity and specificity for detecting and characterizing the lesions. Conclusion The constructed standard dataset can be utilized for evaluating the machine-learning-based AI algorithm for CDSS.

• Progress in Medical Physics
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• v.17 no.4
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• pp.207-211
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• 2006

The advent of kV cone-beam computed tomography (CBCT) integrated with a linear accelerator allows for more accurate Image-guided radiotherapy (IGRT). IGRT is the technique that corrects target displacement based on internal body information. To do this, the CBCT Image set is acquired just before the beam is delivered and registered with the simulation CT Image set. In this study, we compare the registration results according to the CBCT's reconstruction quality (either high or medium). A total of 56 CBCT projection data from 6 patients were analyzed. The translation vector differences were within 1 mm in all but 3 cases. For rotation displacement difference, components of all three axes were considered and 3 out of 168 ($56{\times}3$ axes) cases showed more than lo of rotation differences.

• Journal of the Korean Society of Radiology
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• v.84 no.6
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• pp.1290-1308
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• 2023

Purpose To compare the diagnostic performance of rectal CT with that of high-resolution rectal MRI and histopathology in assessing rectal cancer. Materials and Methods Sixty-seven patients with rectal cancer who underwent rectal CT with rectal distension using sonographic gel and high-resolution MRI were enrolled in this study. The distance from the anal verge/anorectal junction, distance to the mesorectal fascia (MRF), extramural depth (EMD), extramesorectal lymph node (LN) involvement, extramural venous invasion (EMVI), and T/N stages in rectal CT/MRI were analyzed by two gastrointestinal radiologists. The CT findings of 20 patients who underwent radical surgery without concurrent chemoradiotherapy were compared using histopathology. Interclass correlations and kappa statistics were used. Results The distance from the anal verge/anorectal junction showed an excellent intraclass correlation between CT and MRI for both reviewers. For EMD, the distance to the MRF, presence of LNs, extramesorectal LN metastasis, EMVI, T stage, and intermodality kappa or weighted kappa values between CT and MRI showed excellent agreement. Among the 20 patients who underwent radical surgery, T staging, circumferential resection margin involvement, EMVI, and LN metastasis on rectal CT showed acceptable concordance rates with histopathology. Conclusion Dedicated rectal CT may be on par with rectal MRI in providing critical information to patients with rectal cancer.

• Proceedings of the Korea Information Processing Society Conference
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• 2015.04a
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• pp.806-809
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• 2015

급성심근경색증은 우리나라의 3 대 응급질환으로 골든타임 내의 빠른 진단과 처치가 필요하다. 보통 급성심근경색은 질환의 특성상 관상동맥의 상태를 파악하는 것이 중요하기 때문에, 진단을 위한 지표로서 의료 영상이 활용되고 있으며 빠른 진단을 위해서는 효과적인 영상 정보 제공이 요구되는 상황이다. 하지만 기존 시스템은 영상의 형식적인 메타데이터에 의해 식별되어 중요 의료정보를 결여된 평면적인 정보 제공이 이루어지고 있다. 그러나 영상에 내재된 의미적 특징을 기반으로 한 정보 제공이 가능해진다면, 효과적인 영상 정보의 확인이 가능해진다. 따라서 본 논문에서는 급성심근경색의 신속하고 효과적인 진단을 위해, 관련 영상으로부터 의학적으로 가치있는 의료정보들의 의미적 정보를 추출함으로써 개별적인 영상에 분산되어 있던 의료 정보들을 통합하며, 직관적이고 효과적으로 의료 영상정보에 대한 파악을 가능케 한다.

• Journal of the Korean Society of Radiology
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• v.81 no.3
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• pp.467-487
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• 2020

Anatomical imaging is the basis of the diagnosis and treatment response assessment of brain tumors. Among the existing imaging techniques currently available in clinical practice, diffusion-weighted imaging and perfusion imaging provide additional information. Recently, with the increasing importance of evaluation of the genomic variation and heterogeneity of tumors, clinical application of imaging techniques using radiomics and deep learning is expected. In this review, we will describe recommendations for magnetic resonance imaging protocols focusing on anatomical images that are still important in the clinical application of brain tumor imaging, and the basic principles of diffusion-weighted imaging and perfusion imaging among the advanced imaging techniques, as well as their pathophysiological background and clinical application. Finally, we will review the future perspectives of radiomics and deep learning applications in brain tumor imaging, which have been studied to a great extent due to the development of computer technology.

• Journal of the Korean Society of Radiology
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• v.81 no.2
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• pp.272-289
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• 2020

Current advances in CT techniques allow thorough evaluation of the beating heart. The strengths of cardiac CT relative to echocardiography and magnetic resonance imaging are its high availability in most institutions, rapid production of high-quality images, and outstanding delineation of the anatomy. For many normal variants and pathologic conditions, such as thrombi, masses, and congenital abnormalities of the left atrium, CT findings are sufficient to make a presumptive diagnosis. Assessments of the left atrium and left atrial appendage are particularly important for the management of atrial fibrillation, as various catheter-based procedures are aimed at the mechanical and electrical isolation of these structures. CT offers information crucial to a successful catheter-based procedure or surgery. Therefore, a comprehensive review of the geometry (shape, size, and relative position), along with various CT imaging features of pathologic states, should be provided in radiology reports to be of clinical value.

• Proceedings of the Korean Information Science Society Conference
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• 2002.04b
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• pp.634-637
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• 2002

오늘날 CT나 MR등을 통한 의학 영상 기술과 컴퓨터 성능의 향상으로 인체 내부 장기의 영상을 비교적 용이하게 얻을 수 있으며 얻어진 영상 정보는 컴퓨터로 수치와 되므로 데이터의 조작 및 가공이 용이하다. 그러나, 이 데이터는 2D 슬라이스들의 연속으로 표현되므로 이것을 보다 편리하게 가시화. 조작, 분석이 용이한 상태로 바꾸기 위해서는 3차원 구조로의 재구성이 필요하게 된다. 이것을 위하여 무엇보다도 먼저 CT나 MR을 통하여 얻어진 영상을 분석하여 특정 장기의 영상 부분를 다른 조직의 영상부분으로부터 분리(segmentation)할 필요가 있다. 이러한 Segmentation방법에는 여러가지가 있는데, 수작업의 결합 등으로 인해서 비효율적인 문제점을 가지고 있다. 이에 본 논문은 보다 효율적인 segmentation의 처리를 위하여 region-based 기법을 응용하여 새로운 segmentation 방법을 개발하였다. 그리하여, 본 논문이 제안한 알고리즘을 슬라이스 간격이 큰 2차원 복부 CT 영상에 적용시켜 간(liver)의 추출을 시도하였고 향상된 성능을 확인할 수 있었다.