• Investigative Magnetic Resonance Imaging
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• 제23권1호
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• pp.75-80
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• 2019

Metastasis of rhabdomysarcoma to the breast is a very rare manifestation in adult males. Herein, we report a case of metastasis from embryonal rhabdomyosarcoma in the left hypothenar muscle that presented as a breast mass in a 38-year-old man, who four months later expired because of multiple bone metastases related to pancytopenia. We describe the various imaging findings, including mammograms, ultrasonography, computerized tomography (CT), positron emission tomography-computed tomography (PET-CT), and magnetic resonance imaging (MRI) of this rare disease. The various imaging findings of this lesion could be helpful for future diagnosis of male breast lesions.

• 비파괴검사학회지
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• 제18권3호
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• pp.181-190
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• 1998

광원의 직경이 $5{\mu}m$ 수준인 X-선을 이용하여 미세 초점 X-선 단층촬영장치(computerized tomography system)를 제작하고 제어 및 계산 프로그램을 개발하였다. 본 장치는 비파괴검사용으로서 직경 20mm 이내의 시험체를 검사할 수 있다. 단층영상을 얻기 위한 계산 알고리즘으로서는 convolution back projection 알고리즘을 사용하였으며 광원의 형상을 평행 빔과 부채꼴 빔(fan beam) 등 두 종류를 사용하여 결과를 비교하였다. 장치의 제어 및 계산은 개인용 컴퓨터에서 동작하도록 하였다. 제작된 CT 장치와 프로그램을 이용하여 제작된 시편에 대하여 단층 영상을 복원하고 시편의 내부 구조 및 결함을 관찰하였다. 단층영상을 얻은 결과 실제 모습과 일치하는 재료내부의 결함에 대한 정보를 얻을 수 있었으며 해상도는 $20{\sim}30{\mu}m$정도인 것으로 판단되었다.

• Journal of Korean Neurosurgical Society
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• 제49권2호
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• pp.107-111
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• 2011

Objective : The aim of this study was to evaluate the utility of volume-rendered helical computerized tomography (CT) angiography focusing tracheostomy tube and innominate artery for prevention of tracheoinnominate artery fistula. Methods : The authors retrospectively analyzed 22 patients with tracheostomy who had checked CT angiography. To evaluate the relationship between tracheostomy tube and innominate artery, we divided into three categories. First proximal tube position based on cervical vertebra, named "tracheostomy tube departure level (TTDL)". Second, distal tube position and course of innominate artery, named "tracheostomy tube-innominate artery configuration (TTIC)". Third, the gap between the tube and innominate artery, named "tracheostomy tube to innominate artery gap (TTIG)". The TTDL/TTIC and TTIG are based on 3-dimensional (3D) reconstruction around tracheostomy and enhanced axial slices of upper chest, respectively. Results : First, mean TTDL was $6.8{\pm}0.6$. Five cases (23%) were lower than C7 vertebra. Second, TTIC were remote to innominate artery (2 cases; 9.1 %), matched with it (14 cases; 63.6%) or crossed it (6 cases; 27.3%). Only 9% of cases were definitely free from innominate artery injury. Third, average TTIG was $4.3{\pm}4.6$ mm. Surprisingly, in 6 cases (27.3%), innominate artery, trachea wall and tracheostomy tube were tightly attached all together, thus have much higher probability of erosion. Conclusion : If low TTDL, match or crossing type TTIC with reverse-L shaped innominate artery, small trachea and thin TTIG are accompanied all together, we may seriously consider early plugging and tube removal.

• Asian Pacific Journal of Cancer Prevention
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• 제16권14호
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• pp.5599-5605
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• 2015

In oncology various imaging modalities play a crucial role in diagnosis, staging, restaging, treatment monitoring and follow up of various cancers. Stand-alone morphological imaging like computerized tomography (CT) and magnetic resonance imaging (MRI) provide a high magnitude of anatomical details about the tumor but are relatively dumb about tumor physiology. Stand-alone functional imaging like positron emission tomography (PET) and single photon emission tomography (SPECT) are rich in functional information but provide little insight into tumor morphology. Introduction of first hybrid modality PET/CT is the one of the most successful stories of current century which has revolutionized patient care in oncology due to its high diagnostic accuracy. Spurred on by this success, more hybrid imaging modalities like SPECT/CT and PET/MR were introduced. It is the time to explore the potential applications of the existing hybrid modalities, developing and implementing standardized imaging protocols and train users in nuclear medicine and radiology. In this review we discuss three existing hybrid modalities with emphasis on their technical aspects and clinical applications in oncology.

• Asian Pacific Journal of Cancer Prevention
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• 제14권5호
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• pp.2717-2722
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• 2013

Background: The objective of this research is the computed axial tomography (CT) imaging grading of radiation induced pneumonitis (RP) and its correlation with clinical and radiotherapeutic parameters. Materials and Methods: The chest CT films of 20 patients with non-small cell lung cancer who have undergone threedimensional conformal radiation therapy were reviewed. The proposed CT grading of RP is supported on solely radiological diagnosis criteria and distinguishes five grades. The manifestation of RP was also correlated with any positive pre-existing chronic obstructive pulmonary disease (COPD) history, smoking history, the FEV1 value, and the dosimetric variable V20. Results: The CT grading of RP was as follows: 3 patients (15%) presented with ground glass opacity (grade 1), 9 patients (45%) were classified as grade 2, 7 patients (35%) presented with focal consolidation, with or without elements of fibrosis (grade 3), and only one patient (5%) presented with opacity with accompanying atelectasis and loss of pulmonary volume (grade 4). Both univariate and multivariate analysis revealed as prognostic factors for the radiological grading of RP the reduction of FEV1 and the V20 (P=0.026 and P=0.003, respectively). There was also a significant (P<0.001) correlation of radiological grading of RP with FEV1 and V20 (spearman rho 0.92 and 0.93, respectively). Conclusions: The high correlation of the proposed radiological grading with the FEV1 and the V20 is giving a satisfactory clinical validity. Although the proposed grading scale seems relevant to clinical practice, further studies are needed for the confirmation of its validity and reliability.

• 한국전자파학회논문지
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• 제9권6호
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• pp.776-787
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• 1998

835 MHz에서 동작하는 셀룰라 휴대폰에 의한 인체 두부내의 1 g 및 10 g 평균 비홉수율(specific absorption rate, SAR)을 해석한다. 사용되는 수치방법은 총 전자기장 유한차분 시간영역(finite-difference time-domain, FDTD) 기법이다. 전화기는 도체박스, 플라스틱 케이스 그리고 모노폴 안테나와 나선형 안테나 로 구성된 whip 안테나로 모의되었다. 공간 정밀도 3 mm의 이산적 인체두부 모델은 MRI(Magnetic Resonance Imaging), CT(computerized tomography) 그리고 해부학적 이미지에 기초한 것이다 안테나를 뽑은 전화기와 접은 전화기에 대한 근역장 및 원역장 복사 패턴이 분석되었다. SAR 평가를 위한 재현성 있는 기법을 제공하기 위해 조직내의 1 g 또는 10 g의 질량을 갖는 체적을 취하는 두 가지 방법을 제안하고 비교 한다.

• Journal of Mechanical Science and Technology
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• 제16권12호
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• pp.1627-1632
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• 2002

In this paper, a simplified ultrasonic CT system, which uses the information in three directions, that is, 90°, ＋45° and －45°about the inspection plane, is applied to the high strength steel, and the frequency analysis method for enhancing the C scan or CT image is developed. This frequency analysis method is based on the frequency response property of the material. By comparing the magnitudes in the frequency domain, the special frequency which shows a significant difference between the welded joint and base material was found and used to obtain a C scan or CT image. Experimental results for several kinds of specimens, having a welded joint by electron beam welding, a weld joint by arc welding, on a fatigue crack, showed that the obtained C scan or CT image has better resolution than the results of previous experiments using the maximum value of the received waveform.

• Journal of Mechanical Science and Technology
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• 제15권1호
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• pp.52-60
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• 2001

In this paper, as a new measurement method to estimate the change of material condition, the simplified ultrasonic CT system, which uses the information of three directions, that is, $90^{\circ}$, $+45^{\circ}C$and $-45^{\circ}C$ about inspection plane is proposed. Use of simplified CT system has two merits: Firstly, the measurement time is very short compared with general CT. Secondly, it can detect sensitively small defect in vertical or slant direction about inspection plane because the obtained image is CT image calculated from three directions. From these merits, this method can be considered as an effective method to evaluate material conditions. The basic performance of the proposed method was confirmed through several specimens with several simple defects. In order to confirm the applicability of actual NDT, several kinds of welded specimens are investigated. The result showed that the CT image obtained had good agreement with actual defect of specimens.

• 한국산업융합학회 논문집
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• 제11권4호
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• pp.195-199
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• 2008

The carbon fiber has low x-ray absorption property and high stiffness. This is the reason why many CT(Computed Tomography) manufacturer use carbon fiber in couch tabletop for CT scanner. In this paper, we design and make the couch tabletop made of carbon fiber composite, and verify the validity in CT scanner. In designing the couch tabletop, to determine the aluminum equivalent thickness of couch tabletop, we evaluate X-ray the transmissivity of aluminum and carbon plate in 80-120kVp X-ray energy range. And we perform structural analysis and mechanical design using determined thickness of carbon sheet. In conclusion, it was evaluated that manufactured couch tabletop satisfies X-ray transmissivity and mechanical requirements in CT scanner.

• 한국CDE학회논문집
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• 제15권3호
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• pp.234-242
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• 2010

3D CAD technology has been extended to a medical area including dental clinic beyond industrial design. The 2D images obtained by CT(Computerized Tomography) and MRI(Magnetic Resonance Imaging) are not intuitive, and thus the volume rendering technique, which transforms 2D data into 3D anatomic information, has been in practical use. This paper has focused on a method and its implementation for forming 3D geometric surface model from laminated CT images of the pubis. The implemented system could support a dental clinic to observe and examine the status of a patient's pubis before implant surgery. The supplement of 3D implant model would help dental surgeons settle operation plans more safely and confidently. It also would be utilized with teaching materials for a practice and training.