말초혈액 호산구증을 동반하는 국소적 간병변들 : 다양한 질환의 방사선학적 소견

서준범 대한영상의학회 1999 대한영상의학회지 Vol.40 No.1

최근까지 초음파, 전산화 단층촬영, 자기공명 영상 등 영상 진단방법의 발전과 각정 국소적 간병변의 방사선학적 소견에 대한 연구들에 의하여 방사선 검사는 국소적 간병변의 감별진단에서 중요한 역할을 담당하고 있다. 그러나 때때로 여러 방사선학적인 검사에서 비특이적이거나 흔치 않은 소견을 보이는 병변을 만나면 정확한 진단이 어려워진다. 이 때 혈중 호산구증의 존재 여부가 감별진단에 도움을 주는 경우가 있다. 저자들은 혈중 호산구증을 동반할 수 있는 여러 국소 간병변의 방사선학적인 소견을 보여주고자 한다. Due to the recent advent of various imaging modalities such as ultrasonography, computed tomography andmagnetic resonance imaging, as well as knowledge of the characteristic imaging features of hepatic lesions,radiologic examination plays a major role in the differential diagnosis of focal hepatic lesions. However, various'nonspecific' or 'unusual' imaging features of focal hepatic lesions are occasionally encountered, and this makescorrect diagnosis difficult. In such a situation, the presence of peripheral eosinophilia helps narrow thedifferential diagnoses. The aim of this pictorial essay is to describe the imaging features of various diseaseentities which cause focal hepatic lesions and peripheral eosinophilia.

인공지능과 의료혁신

서준범 대한내과학회 2019 대한내과학회 추계학술대회 Vol.2019 No.2

재발한 거대세포종의 자기공명영상

서준범 대한영상의학회 1995 대한영상의학회지 Vol.32 No.6

결절성 간세포암 : 나선상 CT의 동맥강조기와 문맥강조기에서 조영증강양상

서준범 대한영상의학회 1996 대한영상의학회지 Vol.35 No.2

Purpose : To evaluate the enhancing patterns of nodular hepatocellular carcinomas (HCCs) in the arterial- andportal-dominant phases of spiral CT. Materials and Methods : A retrospective analysis of enhancing patterns wasperformed in 100 patients with HCCs diagnosed by pathologic findings (n=30) or clinical and radiological findings.CT images were obtained 30 seconds(arterial-dominant phase) and 65 seconds(portal-dominant phase) after beginninginjection of contrast medium (120mL, 3mL/sec). After transarterial chemoembolization, 179 tumors detected oniodized oil-CT were divided into four groups according to their largest diameter, as follows ; group I(smallerthan 1cm, n=51), II(1-2cm, n=46), III(2-3cm, n=32), IV(larger than 3cm, n=50). The enhancing patterns of tumorscompared with attenuation of surrounding liver parenchyma, were divided into four types, namely high, iso, low andmixed. Results : Each group showed a different enhancing pattern ; group I showed iso-attenuation in botharterial- and portal-dominant phases (n=41, 80% and n=50, 98%), group II showed high-attenuation in thearterial-dominant phase (n=38, 83%) and iso-attenuation in the portal-dominant phase(n=34, 74%), group III showedhigh-attenuation in the arterial-dominant phase(n=19, 59%) and low-attenuation in the portal-dominant phase(n=17,53%), and group IV showed mixed-attenuation in both arterial- and portal-dominant phases(n=30, 60% and n=26, 52%).Conclusion : Hepatocellular carcinomas showed variable enhancing patterns on two-phase spiral CT according to thesize of tumors, and this reflected their hemodynamic characteristics.

특별강연-폐암의 조기발견:영상검사

서준범 대한방사선과학회(구 대한방사선기술학회) 2003 방사선기술과학 Vol.26 No.1

간아세포종의 항암치료전후의 CT소견 : 병리조직과의 비교

서준범 대한영상의학회 1998 대한영상의학회지 Vol.38 No.5

Purpose : The purpose of this study was to analyze the CT findings of hepatoblastoma before and afterchemotherapy, and to compare them with surgical and pathologic features. Materials and Methods : Twelvehepatoblastoma patients underwent chemotherapy prior to surgery; in all cases, CT scanning was performed beforeand after chemotherapy. We reviewed the findings with special attention to changes in tumor volume, the extent andpattern of contrast enhancement, the extent of low-attenuation area in the tumor, the presence of a septum, andcalcification or ossification within the mass before and after chemotherapy. Post-chemotherapy CT findings werecompared with operative and pathologic findings. Results : After chemotherapy, the volume of the tumor massdecreased in all patients, and the extent of involved segments decreased in nine(75%), the non-enhancing areawithin the mass, on the other hand, increased in nine (75%). On pre-chemotherapy CT, calcifications were detectedin seven patients(58%), and on post-chemotherapy CT, in nine (75%); the extent of calcification increased in sevenpatients. On the basis of CT findings, viable tumor and necrosis areas could not be distinguished. Massivecalcification or an osteoid mixed with loose connective tissue was noted in the mesenchymal component of thetumor; the whirling pattern of enhancement within the area of low density asen on CT scanning corresponded toosteoid mixed with loose connective tissue, which contained rich blood vessels. Conclusion : We describe the CTfindings of hepatoblastoma both before and after chemotherapy, highlighting the changes which occurred. Anunderstanding of these changes is helpful for the proper management of this condition.

Trust-HUB 기반 하드웨어 백도어의 구현가능성 분석

서준범(Joon Beom Seo),김동규(Dong Kyue Kim) 대한전자공학회 2020 대한전자공학회 학술대회 Vol.2020 No.8

고해상 CT 영상의 질감특성에 기반한 폐쇄성 폐질환의 자동분류 시스템의 개발에 관한 연구

박성훈,서준범,김남국,이준구,이영경,김성수,채은진 대한영상의학회 2007 대한영상의학회지 Vol.57 No.1

Purpose: To develop an automated classification system for the differentiation of obstructive lung diseases based on the textural analysis of HRCT images, and to evaluate the accuracy and usefulness of the system. Materials and Methods: For textural analysis, histogram features, gradient features, run length encoding, and a co-occurrence matrix were employed. A Bayesian classifier was used for automated classification. The images (image number n=256) were selected from the HRCT images obtained from 17 healthy subjects (n=67), 26 patients with bronchiolitis obliterans (n=70), 28 patients with mild centrilobular emphysema (n=65), and 21 patients with panlobular emphysema or severe centrilobular emphysema (n=63). An five-fold cross-validation method was used to assess the performance of the system. Class-specific sensitivities were analyzed and the overall accuracy of the system was assessed with kappa statistics. Results: The sensitivity of the system for each class was as follows: normal lung 84.9%, bronchiolitis obliterans 83.8%, mild centrilobular emphysema 77.0%, and panlobular emphysema or severe centrilobular emphysema 95.8%. The overall performance for differentiating each disease and the normal lung was satisfactory with a kappa value of 0.779. Conclusion: An automated classification system for the differentiation between obstructive lung diseases based on the textural analysis of HRCT images was developed. The proposed system discriminates well between the various obstructive lung diseases and the normal lung. 목적: 고해상 CT 영상의 질감적 특성을 기반으로 컴퓨터 보조기법을 이용하여 폐쇄성 폐질환을 자동으로 판별하는 방법을 개발하고 이 시스템의 정확도 및 유용성을 검증하고자 하였다. 대상과 방법: 질감적 특성을 이용한 분석을 위하여 히스토그램기반특성, 경계기반특성, runlength 기반특성, co-occurrence기반특성을 이용하였다. Bayesian 분류기를 이용하여 자동화분류를 시행하였다. 17명의 건강한 사람(영상수 n=67), 26명의 폐쇄성 세기관지염 환자(n=70), 28명의 경증 중심소엽성 폐기종 환자(n=65), 21명의 중증 중심소엽성 폐기종 환자 또는 범소엽성 폐기종환자(n=63)에서 얻어진 265개의 HRCT영상을 사용하여 분석하였으며, 5 fold cross-validation 방법을 사용하여 수행능을 평가하였다. 각 대상군별로 진단의 민감도를 알아보았고 전체 시스템의 정확도는 kappa 통계법을 이용하여 알아보았다. 결과: 각각의 질환군과 정상군에서 민감도는 정상 폐 84.9%, 폐쇄성 세기관지염 83.8%, 경증중심소엽성폐기종 77.0%, 전소엽성폐기종 또는 중등도 중심소엽성폐기종 95.8%였다. 각 대상군을 진단하는데 전체적인 수행능은 kappa 치가 0.779 였다. 결론: HRCT 영상의 질감적 특성을 기반으로 폐쇄성 폐질환을 구별하는 자동분류 시스템을 개발하였다. 이 시스템을 이용하여 다양한 폐쇄성 폐질환과 정상 폐를 감별할 수 있다.

심근 생존능: 횡격막 운동 동기화 자유호흡 3차원 역전회복 경사에코 자기공명영상과 호흡정지 2차원 역전회복 경사에코 자기공명영상의 비교

김진희,서준범,도경현,양동현,이수현,고성민,허정남,임태환 대한영상의학회 2004 대한영상의학회지 Vol.51 No.4

Radiation Dose Reduction of Chest CT with Iterative Reconstruction in Image Space - Part I: Studies on Image Quality Using Dual Source CT

황혜전,서준범,이진성,송재우,김성수,이현주,임채훈 대한영상의학회 2012 Korean Journal of Radiology Vol.13 No.6

Objective: To determine whether the image quality (IQ) is improved with iterative reconstruction in image space (IRIS), and whether IRIS can be used for radiation reduction in chest CT. Materials and Methods: Standard dose chest CT (SDCT) in 50 patients and low dose chest CT (LDCT) in another 50 patients were performed, using a dual-source CT, with 120 kVp and same reference mAs (50 mAs for SDCT and 25 mAs for LDCT) employed to both tubes by modifying a dual-energy scan mode. Full-dose data were obtained by combining the data from both tubes and half-dose data were separated from a single tube. These were reconstructed by using a filtered back projection (FBP) and IRIS: full-dose FBP (F-FBP); full-dose IRIS (F-IRIS); half-dose FBP (H-FBP) and half-dose IRIS (H-IRIS). Objective noise was measured. The subjective IQ was evaluated by radiologists for the followings: noise, contrast and sharpness of mediastinum and lung. Results: Objective noise was significantly lower in H-IRIS than in F-FBP (p < 0.01). In both SDCT and LDCT, the IQ scores were highest in F-IRIS, followed by F-FBP, H-IRIS and H-FBP, except those for sharpness of mediastinum, which tended to be higher in FBP. When comparing CT images between the same dose and different reconstruction (F-IRIS/F-FBP and H-IRIS/H-FBP) algorithms, scores tended to be higher in IRIS than in FBP, being more distinct in half-dose images. However, despite the use of IRIS, the scores were lower in H-IRIS than in F-FBP. Conclusion: IRIS generally helps improve the IQ, being more distinct at the reduced radiation. However, reduced radiation by half results in IQ decrease even when using IRIS in chest CT. Objective: To determine whether the image quality (IQ) is improved with iterative reconstruction in image space (IRIS), and whether IRIS can be used for radiation reduction in chest CT. Materials and Methods: Standard dose chest CT (SDCT) in 50 patients and low dose chest CT (LDCT) in another 50 patients were performed, using a dual-source CT, with 120 kVp and same reference mAs (50 mAs for SDCT and 25 mAs for LDCT) employed to both tubes by modifying a dual-energy scan mode. Full-dose data were obtained by combining the data from both tubes and half-dose data were separated from a single tube. These were reconstructed by using a filtered back projection (FBP) and IRIS: full-dose FBP (F-FBP); full-dose IRIS (F-IRIS); half-dose FBP (H-FBP) and half-dose IRIS (H-IRIS). Objective noise was measured. The subjective IQ was evaluated by radiologists for the followings: noise, contrast and sharpness of mediastinum and lung. Results: Objective noise was significantly lower in H-IRIS than in F-FBP (p < 0.01). In both SDCT and LDCT, the IQ scores were highest in F-IRIS, followed by F-FBP, H-IRIS and H-FBP, except those for sharpness of mediastinum, which tended to be higher in FBP. When comparing CT images between the same dose and different reconstruction (F-IRIS/F-FBP and H-IRIS/H-FBP) algorithms, scores tended to be higher in IRIS than in FBP, being more distinct in half-dose images. However, despite the use of IRIS, the scores were lower in H-IRIS than in F-FBP. Conclusion: IRIS generally helps improve the IQ, being more distinct at the reduced radiation. However, reduced radiation by half results in IQ decrease even when using IRIS in chest CT.