• Journal of Korean Orthopaedic Sports Medicine
• /
• v.8 no.1
• /
• pp.60-63
• /
• 2009

Trevor's disease, also known as dysplasia epiphysealis hemimelica, is rare abnormality characterized by aberrant cartilaginous overgrowth forming one half of epiphysis. Typically the patient is 2 to 14 years of age. Until now only six cases, including a case recurred after surgery, have been reported in Korea. A seven year-old boy complained pain of the left knee. However, any deformity of the knee was not seen. The plain radiographic findings showed multiple ossifications asymmetrically on the medial epiphysis of distal femur. The magnetic resonance imaging (MRI) clearly demonstrated the epiphyseal mass which contained low signal spots corresponding to calcified foci and abnormal cartilaginous overgrowth. We report one additional case with a brief review of literature with the MRI findings.

• Journal of the Korean Society of Radiology
• /
• v.6 no.4
• /
• pp.299-303
• /
• 2012

Shoulder MRArthrography was performed to get an accurate diagnosis about complex anatomical structure in shoulder joint. We carried out how the changes of anatomical rotations in shoulder joint could bring certain diagnosis effects on MRI images for various shoulder humerus positions; Neutral position, Internal rotation position and External rotation position. In addition, we prepared an aid tool in oder to maintain the right posture of a patient. This aid tool was made by adapting Modeling Design Program. By virtue of this aid, we obtained the following result. Shoulder MR Arthrography by the External rotation position for anatomical structure diagnosis was the most suitable in diagnostic evaluations of important anatomical structures in shoulder joint such as Biceps tendon, Supera-spiatus tendon, Sub-scapularis tendon, Labrum and Sub-acromial space.

• Investigative Magnetic Resonance Imaging
• /
• v.10 no.1
• /
• pp.16-19
• /
• 2006

Synovial sarcoma is rare soft tissue tumor mesenchymal origin. Osseous involvement of synovial sarcoma is rare. A 24-year-old man presented with pain and swelling of the lower extremity. MRI of the lower extremity demonstrated a large mass encircling tibia with osseous involvement. Surgical excision of the mass was done and the mass was diagnosed as biphasic synovial sarcoma with bone marrow involvement. We also discuss the other imaging findings of synovial sarcoma on MRI.

• Korean Journal of Cognitive Science
• /
• v.17 no.1
• /
• pp.1-13
• /
• 2006

We applied fMRI to examine brain activation at intentionality detection (ID) task. The main purpose of this study was to explore whether brain activation regions involved in intentionality detection (known as the basic mechanism of theory of mind) differ or not, according to prior instruction. Left uncus, superior temporal gyrus and right inferior occipital gyrus, supramarginal gyrus, inferior parietal lobule, thalamus (medial dorsal nucleus), and precuneus were activated with prior instruction. In contrast, ID task with no instruction activated merely inferior parietal lobule and superior parietal lobule. Common activated area between the two instruction conditions was inferiordparietal lobule. Our results suggest thar prior instruction activated ID-related brain regions more explicitly. furtherdinvestigations would be loused on spontaneity of intentionality detector and characteristic of participants.

• Progress in Medical Physics
• /
• v.12 no.1
• /
• pp.31-39
• /
• 2001

NMR spectroscopy enables us to measure the molar concentration of the metabolites in the organisms, and this technique is the only method to measure the concentration non-invasively. The proton NMR spectroscopy has been used to study the biochemical changes in human as well as in animal brain. MRI uses the proton densities and its relaxation times for reconstructing images, but MRS gives the biochemical changes inside the body. NMR spectroscopy could provide the information which MRI and CT could not, and this makes NMR spectroscopy more useful in diagnosing diseases. This study was tried to develop the quantitation of the molar concentration of the metabolites in the brain using the proton MR spectroscopy. The spectra of each metabolites was obtained, and the proton MR spectra was obtained from the insula gray matter areas of the 16 volunteers. And this spectra was analyzed to estimated the molar concentrations of the metabolites in the region. The results showed the very similar to those of the others.

• Journal of the Korean Society of Radiology
• /
• v.12 no.5
• /
• pp.699-706
• /
• 2018

In this study, we measured signal intensities according to array coil position changes to provide reference data of coil directions and the distances as it deters image quality unless the coils are aligned properly. The multi-purpose MRI phantom was placed in body array coils, and it was moved to the top, bottom, left, and right directions by 2 cm from the center to 10 cm. After obtaining images, signal intensities were measured and compared. The results of this study were as follows: Except for the upward direction, the signal intensities of the reference signal was not significantly different from that of the reference signal intensity within 2cm in both T1 and T2-weighted images. In conclusion, in clinical circumstances which various challenges exist to align the coils exactly on the same lines, array coils should be positioned at least within 2 cm from the center except for the upward direction, on the same line to prevent the image qualities are lowered.

• Journal of radiological science and technology
• /
• v.29 no.3
• /
• pp.157-165
• /
• 2006

In order to analyze clinical characteristics like sex- and age-based onset frequency and onset region from vertebral disease cases, this study investigated total 1,291 cases of vertebral disease that were diagnosed via magnetic resonance imaging(MRI) from January to December 2004 at B University Hospital in metropolitan area. For higher diagnostic accuracy in cases of spinal disorder diagnosed, this study analyzed findings from data reading conducted by veteran specialists in diagnostic radiology. But this study excluded uncertain lesion cases, the cases requiring differential diagnosis from other disorders and so on from subjects under analysis. This study employed superconductive 1.5 Tesla SIGNA MR/i for MRI test and basically received resulting images via FSE(fast spin echo). In particular, this study obtained T1 and T2 myelogram with regard to regional characteristics(such as cervical vertebrae, thoracic vertebrae and lumbar vertebra) and imaging characteristics for sagittal and transverse section. As a result, this study came to the following conclusions : 1. In terms of general characteristics of subjects under analysis, male group comprised 53.5% and female 46.5% out of total 1,291 subjects. 2. The regional onset frequency of spinal disorders was converged primarily on lumbar vertebra(65.5%), which was followed by cervical vertebrae(27.3%) and thoracic vertebrae(7.0%) respectively. 3. Top 10 cases with high onset frequency of spinal disorders can be listed as follows : 1) posterior bulging disc 65.8% 2) narrowing of neural foramen 23.8% 3) herniated intervertebral disc (HIVD) 22.4% 4) spinal stenosis 16.7% 5) osteochondrosis 6.4% 6) compression fracture 6.4% 7) facet joint arthropathy 6.2% 8) spondylolisthesis 6.0% 9) spinal cord tumor 3.5% 10) inter body fusion 2.6%

• Proceedings of the KSMRM Conference
• /
• 2002.11a
• /
• pp.104-104
• /
• 2002

목적： SAAV sequence를 이용하여 동시에 획득한 동맥과 정맥의 두 MRA 영상을 Color Mapping으로 동맥과 정맥을 구분하여 한 영상에 나타냄으로써 AVM 이나 DAVF 등과 같은 혈관질환의 임상적 진단 및 치료에 도움을 주고자 하였다. 대상 및 방법： 일반적으로 MRA 영상은 사전 포화방법(presaturation)을 이용한 2D TOF 기법을 통하여 동맥과 정맥을 구분하여 영상을 획득한다. 이러한 일반적인 사전포화방법을 응용한 SAAV 기법은 일정영역을 미리 포화(saturation)시킨 후 포화영역의 위, 아래의 영역을 한번에 영상화하여 동맥과 정맥의 구분된 영상을 한번에 획득할 수 있다. 마산 삼성병원의 0.3T MRI system(Megfinder, AILab. Korea)에서 SAAV sequence를 이용하여 정상적인 피험자로부터 목 부위의 동맥과 정맥 혈관영상을 동시에 얻었다. 이들의 각 2D 영상을 Color Mapping으로 조합한 후 Maximum Intensity Projection(MIP) 기법을 통해 3D Artery-Vein Color Mapping(AVCM) MRA 영상으로 재구성하였다. 3명의 피험자에 대한 SAAV MRA data를 256$\times$256$\times$64(resolution： 0.89$\times$0.89$\times$2㎣)로 획득하였다.

• Proceedings of the KSMRM Conference
• /
• 2002.11a
• /
• pp.75-75
• /
• 2002

목적： 고자장 자기공명영상 시스템 등으로 신호대잡음비가 향상됨에 따라 데이터 측정에서 analog-to-digital converter (ADC)의 quantization noise 가 중요한 시스템 사양으로 부각되고 있다. 특히 자기공명영상은 공간주파수 영역에서 데이터를 측정하기 때문에 dc와 ac간의 신호 차이가 매우 크며, 이러한 dynmic range는 3-D 영상에서 더욱 커진다. 본 연구에서는 다양한 자기총명 영상기법 및 실험 파라미터에 따른 신호의 dynamic range와 ADC의 bit 수에 따른 quantization noise를 살펴봄으로써, 주어진 시스템에 적합한 ADC의 bit 수를 분석하고자 한다. 대상 및 방법： 펄스 시퀀스의 종류, 파라미터, 2D/3D 등에 따른 각 신호의 크기를 수학적으로 모델링하여 신호의 크기를 예측하였다. 또한 whole body MRI 시스템에서 실험을 통하여 신호의 크기를 비교하였다. ADC의 quantization noise를 실험과 시뮬레이션을 통하여 살펴보았다. 시뮬레이션은 test 영상을 Inverse FFT 하여 spatial frequency domain data를 만든 후, 다양한 bit 수의 ADC로 quantization을 한 후 다시 영상을 재구성하였다. 재구성된 영상과 원영상 간의 error가 quantization noise가 된다. 또한 이러한 error가 주파수 영역에서의 error 값과 일치하는지를 확인하였다.

• Journal of Biomedical Engineering Research
• /
• v.22 no.3
• /
• pp.303-309
• /
• 2001

It is well known that the electrical impedance of biological tissues is very sensitive to their temperature. In this paper, we have analyzed the effects of temperature change on the phase of magnetic resonance images obtained with external current injection. It has been found that the local phase in the current injected magnetic resonance image can be changed noticeably when local temperature change appears at a part of the tissue. At the experiments with a 0.3 Tesla MRI system, we observed the local phase changes at the phantom images when the phantom temperature was varied between 25 -45$^{\circ}C$. We think that the current injection MRI technique can be used for in-vivo monitoring of the temperature inside biiological tissues if the relation between the local temperature and phase can be quantified.