• 한국전기전자재료학회논문지
• /
• 제23권10호
• /
• pp.820-825
• /
• 2010

In this study, we intended to design the optimal Fermi filter to apply the k-space date that is knee image of the rheumatoid arthritis patient acquired from the MRI (magnetic resonance imaging) instrument. After deciding the suitable coefficient for the Fermi filter, the results were compared with modified Fermi filter and inverse Chebyshev filter, Chebyshev filter, Elliptic filter and Butterworth filter. Firstly, in comparison to the results, the radiologist confirmed that modified Fermi filter was best decision for boundary of the rheumatoid arthritis images. The number of the black voxels of the histogram showed the quantity of the results. At the proposed filter images, numbers of the blacks voxels were statistically decreased. That meant voxels only appeared the black color were changed to others voxels color. Because the number of the total voxels was fixed, the area appeared block color could be effected to the other areas. If the modified Fermi filter were used for rheumatoid arthritis patient, the result will be better than other filters.

• Journal of Korean Neurosurgical Society
• /
• 제51권3호
• /
• pp.170-172
• /
• 2012

Central nervous system (CNS) sparganosis is a rare parasitic infestation caused by ingestion of the raw or inadequately cooked snakes or frogs. Sparganum is well known for its ability of migrating though the tissue, therefore, it can cause various neurological symptoms if it involves neurological systems. A 51-year-old male patient visited our department of neurosurgery complaining of the motor weakness and radiating pain on both upper extremities over 4 months. He had a history of ingesting raw snakes untill his late twenties. The magnetic resonance (MR) images of. cervical spine revealed an intramedullary ill-defined enhancing lesion with the aggregated cysts in the upper cervical spinal cord. Under presumptive diagnosis of sparganosis, we took brain MR image. The brain MR images revealed the signal change in right fronto-temporallobe suggesting the trajectory of parasitic migration via ventricular systems. He underwent a midline myelotomy and granuloma removal followed by the posterior laminoplasty. Pathologic findings showed inflammatory changes and necrosis with keratinized tissue suggesting the CNS sparganosis. We report an uncommon case of CNS sparganosis migrated from the brain to the spinal cord with literature review.

• 대한자기공명의과학회:학술대회논문집
• /
• 대한자기공명의과학회 2001년도 제6차 학술대회 초록집
• /
• pp.109-109
• /
• 2001

Purpose： To assess the feasibility of sequential administration of ferumoxides and mangafodi trisodium in the same imaging protocols. Method： Thirty patients underwent double-contrast enhanced MR imaging of liver usi ferumoxides (Fe-MRI) and mangafodipir trisodium (Mn-MRI) on 1.5T GE Horizon system. In twenty patients, Mn-MRI was immediately followed by Fe-MRI. In ten patients, Fe-MR was performed first, then Mn-MRI was performed immediately, In all cases, precontras T1-weighted in-phase and opposed-phase spoiled gradient echo (GRE) images an T2-weighted fast spin-echo images (TR 4000ms, TE 102ms, ETL 8-12) were obtained Fe-MRI was performed with FSE and steady state GRE (TE 10 msec, flip angle 30 sequences. Mn-MRI was performed with in-phase and opposed-phase spoiled GR sequences. The SNR changes after the use of each contrast agents were calculated.

• 대한의용생체공학회:의공학회지
• /
• 제23권2호
• /
• pp.101-107
• /
• 2002

이 논문에서는 자기공명심장영상에서 내벽과 외벽의 추출을 위한 반자동 분할 알고리즘을 제안하였다. 이 알고리즘은 Generalized gradient vector flow snake와 초기 윤곽선 예측 과정을 기반으로 한다. 특히 이 알고리즘은 내벽과 외벽의 공간적인 특설을 이용하며 Cross profile correlation matching (CPCM)을 사용한다. 현재 공간에서의 이전 시간에 관계된 영상과 현재 시간에서의 공간에 관계된 영상을 사용하여 초기 윤곽선 예측을 더욱 효과적으로 수행하였다. Multislice와 multiphase의 Siemens와 GE. Medinus 자기공명심장영상을 사용하여 실험하였고 많은 영상들에 대해 충분히 만족할만한 결과를 얻었다. 그리고 분할한 결과로 quantitative analysis를 수행하였고 시각적으로 보여주었다. 개발된 소프트웨어는 Visual C++을 사용하여 windows 환경의 응용프로그램으로 개발되었다.

• 대한자기공명의과학회:학술대회논문집
• /
• 대한자기공명의과학회 2002년도 제7차 학술대회 초록집
• /
• pp.106-106
• /
• 2002

Purpose： The purposes of our study are (1) to develop a brain phantom which can be used for multimodal image registration, (2) to evaluate the accuracy of image registration with the home-made phantom. Method： A brain phantom which could be used for image registration technique of CT-MR and CT-SPECT images using chamfer matching was developed. The brain phantom was specially designed to obtain imaging dataset of CT, MR, and SPECT. The phantom had an external frame with 4 N-shaped pipes filled with acryl rods for CT, MR imaging and Pb rods for SPECT imaging. 8 acrylic pipes were inserted into the empty space of the brain phantom to be imaged for geometric evaluation of the matching. Accuracy of image fusion was assessed by the comparison between the center points of the section of N-shaped bars in the external frame and the inserted pipes of the phantom. Technique with partially transparent, mixed images using color on gray was used for visual assessment of the image registration process.

• Investigative Magnetic Resonance Imaging
• /
• 제22권2호
• /
• pp.131-134
• /
• 2018

Susceptibility-weighted imaging (SWI) is well known for detecting the presence of hemorrhagic transformation, microbleeds and the susceptibility of vessel signs in acute ischemic stroke. But in some cases, it can provide the tissue perfusion state as well. We describe a case of a patient with hyperacute ischemic infarction that had a slightly hypodense, patchy lesion at the left thalamus on the initial SWI, with a left proximal posterior cerebral artery occlusion on a magnetic resonance (MR) angiography and delayed time-to-peak on an MR perfusion performed two hours after symptom onset. No obvious abnormal signals at any intensity were found on the initial diffusion-weighted imaging (DWI). On a follow-up MR image (MRI), an acute ischemic infarction was seen on DWI, which is the same location as the lesion on SWI. The hypointensity on the initial SWI reflects the susceptibility artifact caused by an increased deoxyhemoglobin in the affected tissue and vessels, which reflects the hypoperfusion state due to decreasing arterial flow. It precedes the signal change on DWI that reflects a cytotoxic edema. This case highlights that, in some hyperacute stages of ischemic stroke, hypointensity on an SWI may be a finding before the hyperintensity is seen on a DWI.

• 한국임상수의학회지
• /
• 제24권2호
• /
• pp.247-250
• /
• 2007

3년령의 암컷 잉글리쉬 코카 스패니얼 견이 급성 사지마비 증상을 나타내었다. 자기공명영상검사를 통해, 신경반응의 결손이 척수의 초급성 출혈에 기인함을 진단하였다. 자기공명영상은 T2 강조 영상에서 실질조직의 고신호로 동일부위의 T1 강조 영상에서는 저신호로 나타났다. 자기공명영상에서 나타난 특징적 소견에 의거하여 출혈성 척수연화증으로 잠정 진단하였고 사후 부검시 조직병리학적 검사를 통해 확증하였다.

• 한국정보과학회논문지:소프트웨어및응용
• /
• 제27권8호
• /
• pp.846-854
• /
• 2000

본 논문에서는 대퇴골두 무혈성 괴사의 자동 진단을 위한 효과적인 대퇴골두 영역의 추출 방법을 제안한다. 대퇴골두의 해부학적 특성과 Hough 변환을 이용하여 대퇴골두 영역을 설정하였고, 변형된 영역 확장법을 적용하여 대퇴골두 영역을 분할하였다. 그리고, 분할된 영역으로부터 대퇴골두 무혈성 괴사의 진단에 필요한 인자를 자동으로 측정하였다. 본 논문에서 제안한 영역 추출 방법은 정상적인 대퇴골두와 무혈성 괴사의 초기 단계의 대퇴골두 뿐만 아니라 괴사가 심한 대퇴골두에 대해서도 좋은 결과를 얻을수 있었고, 본 논문에서 제안한 방법으로 측정된 인자는 대퇴골두 무혈성 괴사의 정량적인 분석 및 진단을 가능하게 한다.

• 대한방사선기술학회지:방사선기술과학
• /
• 제44권2호
• /
• pp.123-131
• /
• 2021

In this study, safety education contents for medical radiation workers were produced based on Mixed Reality(MR). Currently, safety training for radiation workers is based on theory. This is insufficient in terms of worker satisfaction and efficiency. To address this, we created ICT(Information and Communication Technologies)-based MR radiation worker safety education content. The expected effect of Mixed Reality worker safety education content is that education is possible without space and time constraints, realistic education is possible without on-site training, and interaction between images is possible through reality-based 3D images, enabling self-directed learning Is that. In addition, learning in a virtual space expressed through HMD(Head Mounted Display) is expected to make education more enjoyable and increase concentration, thereby increasing the efficiency of education. A quantitative evaluation was conducted by an accredited institution and a qualitative evaluation was performed on users, which received excellent evaluation. The MR safety education conducted in this study is expected to be of great help to the education of medical radiation workers, and is expected to develop into a new educational paradigm as online education in accordance with Corona 19 progresses.

• Korean Journal of Radiology
• /
• 제2권1호
• /
• pp.37-41
• /
• 2001

Because the tongue is superficially located and the intial manifestation of most diseases occurring there is mucosal change, lingual these lesions can be easily accessed and diagnosed without imaging analysis. Most congenital lesions of the tongue, however, can manifest as a submucosal bulge and be located in a deep portion of that organ such as its base; their true characteristics and extent may be recognized only on cross-sectional images such as those obtained by CT or MRI. In addition, because it is usually difficult to differentiate congenital lesions from other submucosal neoplasms on the basis of imaging findings alone, clinical history and physical examination should always be taken into consideration when interpretating CT and MR images of the tongue. Although the radiologic findings for congenital lesions are nonspecific, CT and MR imaging can play an important role in the diagnostic work-up of these unusual lesions. Delineation of the extent of the tumor, and recognition and understanding of the spectrum of imaging and the pathologic features of these lesions, often help narrow the differential diagnosis.