• Journal of the Korean Arthroscopy Society
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• v.12 no.3
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• pp.198-204
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• 2008

Purpose: The purpose of this study is to analyze the merits and demerits of double bundle reconstruction and achieve improvements hereafter, by comparing the results of double bundle and single bundle reconstruction using tibialis anterior allograft. Materials and Methods: Twenty seven patients were divided to undergo either double bundle(n=14) or single bundle(n=13) reconstruction with tibialis anterior allograft tendon. The evaluation methods were AP laxity with KT-2000 arthrometer, isokinetic knee strength measurements, pivot-shift test, IKDC subjective score, Lysholm knee score, Tegner activity score, radiographic evaluations with postoperative MRI, and second look arthroscopy. Results: Lysholm knee score and Tegner activity score were significantly better in double bundle reconstruction. In pivot-shift test, single bundle reconstruction was evaluated as grade 0 in 10 of the knees, grade 1 in 1, and grade 2 in 2. Double bundle reconstruction was evaluated as grade 0 in 13, and grade 2 in 1. In second look arthroscopy, single bundle was evaluated as excellent in 6 of the knees, fair in 7, anteromedial bundle of double bundle reconstruction was excellent in 13 and fair in 1, and posterolateral bundle was excellent in 4, fair in 9, and poor in 1. There were no significant differences in other evaluations. Conclusion: Favorable outcome may be expected with double bundle reconstruction of ACL. However there are still need for improvement in terms of reconstruction technique and rehabilitation protocol to reduce PL bundle injury.

• The Journal of the Korea Contents Association
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• v.15 no.11
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• pp.313-321
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• 2015

To minimize CT examination for Hip FAI diagnosis and operation plan. also, whether the MRI 3D images can replace Hip Clock face image was evaluated when performing Hip FAI MRI by using additional 3D image. This study analyzed Hip MRI and 3D Hip CT images of 31 patients in this hospital. For the purpose of evaluating the images, one orthopedic surgeon and one radiology specialist reconstructed Clock face, at MR and CT modality, by superior 12 o'clock, labrum front 3 o'clock, and the other side 9 o'clock, centering on Hip joint articular transverse ligament 6 o'clock. Afterwards, by the Likert Scale 5 point scale (independent t-test p<0.005), this study evaluated the check-up of A. retinacular vessel, B. head neck junction at 11 o'clock, A. Epiphyseal line, B. Cam lesion at 12 o'clock, and Cam lesion, Posterior Cam lesion at 1,2,3 and 4 o'clock. As for the verification of reliability among observers, this study verified coincidence by Cohen's weighted Kappa verification. As a result of Likert scale for the purpose of qualitative evaluation about the image, 11 o'clock A. retinacular vessel MR average was $3.69{\pm}1.0$ and CT average was $2.8{\pm}0.78$. B. head neck juncton didn't have a difference between two observers (p <0.416). 12 o'clock A. Epiphyseal line MR average was $3.54{\pm}1.00$ and CT average was $4.5{\pm}0.62$(p<0.000). B. Cam lesion didn't have a difference between two observers (p <0.532). 1,2,3,4 Cam lesion and Posterior Cam lesion were not statistically significant (p <0.656, p <0.658). As a result of weighted Kappa verification, 11 o'clock A.retinacular vessel CT K value was 0.663 and the lowest conformity. As a result of coincidence evaluation on respective item, a very high result was drawn, and two observers showed high reliability.

• Journal of Korean Medicine Rehabilitation
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• v.20 no.4
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• pp.241-254
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• 2010

Anterior cruciate ligament tear is a common disease of knee injury. We report 1 case of anterior cruciate ligament complete tear diagnosed by MRI(magnetic resonance imaging) imaging and 1 case after reconstruction. Outcomes were measured by visual analogue scale(VAS) and Lysholm knee scoring scale. We applied acupuncture treatment, bee venom injection, bongchuna and prescribed herbal medication. Patients who treated by oriental medical treatments had a significant effect on the pain decrease and range of motion and knee function. Oriental medical treatments are very useful on pain reduction and prevention of muscle contraction, leading to satisfied rehabilitation, as wee as diminishing recurrence after operation.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• v.14 no.1
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• pp.35-42
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• 2010

A goal of Magnetic Resonance Imaging is reproducing a spatial map of the effective spin density from the measured Fourier coefficients of a specimen. The imaging procedure can be done by inverse Fourier transformation or backward fast Fourier transformation if the data are sampled on a regular grid in frequency space; however, it is still a challenging question how to reconstruct an image from a finite set of Fourier data on irregular points in k-space. In this paper, we describe some mathematical and numerical properties of imaging techniques from non-uniform MR data using the pseudo-inverse or the diagonal-inverse weight matrix. This note is written as an easy guide to readers interested in the non-uniform MRI techniques and it basically follows the ideas given in the paper by Greengard-Lee-Inati [10, 11].

• Proceedings of the KOSOMBE Conference
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• v.1992 no.05
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• pp.64-67
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• 1992

To improve signal-to-noise ratio in sodium image, short echo time (2-3 ms) and long data acquisition (10-20 ms) protocols are used. Sodium in biological specimens demonstrates a bi-exponential decay of transverse magnetization and the fast decaying component of the sodium signal results in the reconstruction of images which are blurred significantly. The spatially-dependent nature of the blurs are due mainly to the presence of short local transverse relaxation values (0.7-3 ms) of sodium in tissue. We present an algorithm that corrects for object-dependent blurs due to fast-decaying T2 and improves the computational behavior of the algorithm by incorporating a relaxation parameter into the iterative process.

• Proceedings of the KSMRM Conference
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• 1999.04a
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• pp.34-42
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• 1999

의료영상에서 인공물(Artifacts) 이라 함은 영상이 얻어지는 신체부위와 아무런 관련이 없으나 얻어진 영상에는 마치 영상의 일부분으로 나타나는 모든 것을 가리킨다. 따라서 영상에서 이들 인공물들은 실제 조직의 해부학적인 구조를 나타내지 않으므로 영상 판독에 영향을 주어 잘못된 진단을 초래할 수도 있다. 그러나 MR 영상이 가능한 이래로 새로운 여러 종류의 MR 인공물들이 많이 발견 되었으나 다행스럽게도 거의 모든 MR 인공물들은 쉽게 설명이 가능하며, 따라서 이들 인공물들에 의한 진단 오류의 가능성은 매우 희박한 실정이다. 그러나 새로운 영상방법이나 혹은 새로운 펄스대열이 계속 고안됨에 따라 새로운 종류의 인 공물들이 생겨날 가능성은 항상 존재하고 있다. 지금까지 알려진 여러 MR 인공물들은 그 생겨난 원인에 따라 다음과 같이 크게 세 가지로 분류가 가능하다. I. Motion Artifacts 1. Voluntary motion 2. Involuntary motion 1) Bowel Peristalsis 2) Respiration 3) Cardiac and vessel pulsation 4) Swallowing 3. Fluid motion 1) Blood flow 2) Cerebrospinal fluid flow II. Reconstruction Artifacts 1. Aliasing 2. Partial volume averaging 3. Truncation (Ringing) 4. Central point III. Magnetic and RF Field Related Artifacts 1. Chemical shift 1) First kind 2) Second kind 2. Susceptibility 1) Dental 2) Metal 3. Magic angle 4. Zipper 5. Bad data point 6. RF field inhomogeneity 7. Magnetic field inhomogeneity 8. Eddy current 9. slice overlapping 10. Zebra 11. RF overflow

• Proceedings of the KOSOMBE Conference
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• v.1998 no.11
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• pp.277-278
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• 1998

CT/MRI images were frequently taken to evaluate the anatomic structure and disease status, and to plan the treatment modality for oral and maxillofacial surgery. However, surgeons have many difficulties in reading and understanding 2D images without long time experiences. This study presents the method of 3D reconstruction with fine CT slices and its clinical application. We applied this method a clinical patient with oral and maxillofacial trauma and produced 3D reconstructed model which shows the fracture line in panfacial area and bone defect.

• 한국지구물리탐사학회:학술대회논문집
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• 2007.06a
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• pp.1-6
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• 2007

Two impedance imaging systems of multi-frequency electrical impedance tomography (MFEIT) and magnetic resonance electrical impedance tomography (MREIT) are described. MFEIT utilizes boundary measurements of current-voltage data at multiple frequencies to reconstruct cross-sectional images of a complex conductivity distribution (${\sigma}+i{\omega}{\varepsilon}$) inside the human body. The inverse problem in MFEIT is ill-posed due to the nonlinearity and low sensitivity between the boundary measurement and the complex conductivity. In MFEIT, we therefore focus on time- and frequency-difference imaging with a low spatial resolution and high temporal resolution. Multi-frequency time- and frequency-difference images in the frequency range of 10 Hz to 500 kHz are presented. In MREIT, we use an MRI scanner to measure an internal distribution of induced magnetic flux density subject to an injection current. This internal information enables us to reconstruct cross-sectional images of an internal conductivity distribution with a high spatial resolution. Conductivity image of a postmortem canine brain is presented and it shows a clear contrast between gray and white matters. Clinical applications for imaging the brain, breast, thorax, abdomen, and others are briefly discussed.

• Journal of the Korea Society for Simulation
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• v.6 no.2
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• pp.31-44
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• 1997

In medical applications, the cooperation work using computer network is in the spotlight as next generation technology, because it offers sharing of equipments, knowledge of specialists, and data and surmounts the limitations of geographical position and time. We present a prototype of telepresent surgical simulation system in this treatise. It is a telemedicine system using volume image, which is reconstructed from radiological images such as MRI and CT. It is used as a tool for surgical simulation among telepresent doctors. It provides the functions of conference control, volume reconstruction and manipulation, and multimedia database management among one server and multi-clients through high-speed network. It is implemented on Unix workstation using X-windows and C language, TCP/IP protocol and UNiSQL as DBMS.

• Investigative Magnetic Resonance Imaging
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• v.26 no.1
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• pp.1-9
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• 2022

Artificial intelligence (AI) powered by deep learning (DL) has shown remarkable progress in image recognition tasks. Over the past decade, AI has proven its feasibility for applications in medical imaging. Various aspects of clinical practice in neuroimaging can be improved with the help of AI. For example, AI can aid in detecting brain metastases, predicting treatment response of brain tumors, generating a parametric map of dynamic contrast-enhanced MRI, and enhancing radiomics research by extracting salient features from input images. In addition, image quality can be improved via AI-based image reconstruction or motion artifact reduction. In this review, we summarize recent clinical applications of DL in various aspects of neuroimaging.