• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.22 no.12
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• pp.1124-1131
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• 2011

In this paper, image reconstruction algorithm for breast cancer detection using MT(Microwave Tomography) was investigated. The breast cancer detection system under development uses 16 transmit/receive antennas. The signal waveform was a sinusoidal wave at 900 MHz. To solve the 2D inverse scattering problem, we used the 2D FDTD (Finite Difference Time Domain) method for forward calculation and LMA(Levenberg-Marquardt Algorithm) for optimization. The result of the image reconstruction using the numerical phantom by MRI(Magnetic Resonance Imaging) obtained from real patient of breast cancer showed that we can detect the position of the tumor accurately.

• Clinics in Shoulder and Elbow
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• v.1 no.2
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• pp.154-159
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• 1998

Medial dislocation of the long head of the biceps brachii is a rare condition that usually occurs in association with tears of the subscapularis, chronic impingement, capsular defects or a fracture of the lesser tuberosity. Less commonly, a biceps tendon dislocation may occur after an acute traumatic event. Following a dislocation, the biceps tendon will assume either an intra- or extra-articular position depending on whether or not the subscapularis tendon detaches from its humeral insertion. Magnetic resonance imaging has been found to provide valuable information concerning the location of the biceps tendon and the integrity of the subscapularis tendon. We present a patient with a traumatic dislocation of the biceps brachii tendon in which the diagnosis remained elusive for an extended period of time. In this case, he was evaluated using MRI and reconstruction was performed by restoring the tendon to its anatomical position.

• Nuclear Medicine and Molecular Imaging
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• v.42 no.2
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• pp.83-87
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• 2008

Diagnostic and functional imaging device have been developed independently. The recognition that combining of these two devices can provide better diagnostic outcomes by fusing anatomical and functional images. The representative examples of combining devices would be PET/CT and SPECT/CT. Development and their applications of animal imaging and instrumentation have been very active, as new drug development with advanced imaging device has been increased. The development of advanced imaging device resulted in researching and developing for detector technology and imaging systems. It also contributed to develop a new software, reconstruction algorithm, correction methods for physical factors, image quantitation, computer simulation, kinetic modeling, dosimetry, and correction for motion artifacts. Recently, development of MRI and PET by combining them together was reported. True integration of MRI and PET has been making the progress and their results were reported. The recent status of imaging and instrumentation in nuclear medicine is reported in this paper.

• Journal of the Korean Arthroscopy Society
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• v.16 no.2
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• pp.147-152
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• 2012

Purpose: The purpose of this study was to compare the preoperative magnetic resonance image (MRI) findings with postoperative arthroscopic findings on meniscus injury with anterior cruciate ligament (ACL) rupture. Materials and Methods: We reviewed MRI images and arthroscopic findings of 225 patients treated by ACL reconstruction due to rupture, from February 2001 to November 2010. There were 154 cases of meniscus tear in arthroscopic findings. We examined the sensitivity for detecting meniscal tears varied with the presence of a rupture of the ACL, with the location of the tear within the meniscus, and among configurations of meniscal tears. Results: In the presence of a rupture of the ACL, the sensitivity of MRI was 0.88 for medial meniscal tears and 0.69 for lateral meniscal tears. And sensitivity of MRI was lowest in posterior horn and peripheral portion tears in lateral meniscus injury accompanying ACL rupture, sensitivity was low in anterior horn and flap shape tears in medial meniscus injury accompanying ACL rupture. Conclusion: In Meniscus injury with ACL rupture, a special attention shoulder given to the posterior horn and peripheral portion injury in lateral meniscus during arthroscopic surgery due to difficulty in detecting on MRI.

• Investigative Magnetic Resonance Imaging
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• v.18 no.4
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• pp.303-313
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• 2014

Purpose : In-vivo conductivity reconstruction using transmit field ($B_1{^+}$) information of MRI was proposed. We assessed the accuracy of conductivity reconstruction in the presence of statistical noise in complex $B_1{^+}$ map and provided a parametric model of the conductivity-to-noise ratio value. Materials and Methods: The $B_1{^+}$ distribution was simulated for a cylindrical phantom model. By adding complex Gaussian noise to the simulated $B_1{^+}$ map, quantitative conductivity estimation error was evaluated. The quantitative evaluation process was repeated over several different parameters such as Larmor frequency, object radius and SNR of $B_1{^+}$ map. A parametric model for the conductivity-to-noise ratio was developed according to these various parameters. Results: According to the simulation results, conductivity estimation is more sensitive to statistical noise in $B_1{^+}$ phase than to noise in $B_1{^+}$ magnitude. The conductivity estimate of the object of interest does not depend on the external object surrounding it. The conductivity-to-noise ratio is proportional to the signal-to-noise ratio of the $B_1{^+}$ map, Larmor frequency, the conductivity value itself and the number of averaged pixels. To estimate accurate conductivity value of the targeted tissue, SNR of $B_1{^+}$ map and adequate filtering size have to be taken into account for conductivity reconstruction process. In addition, the simulation result was verified at 3T conventional MRI scanner. Conclusion: Through all these relationships, quantitative conductivity estimation error due to statistical noise in $B_1{^+}$ map is modeled. By using this model, further issues regarding filtering and reconstruction algorithms can be investigated for MREPT.

• Journal of Electrical Engineering and Technology
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• v.10 no.5
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• pp.2197-2204
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• 2015

In recent years, medical image diagnosis has growing significant momentous in the medicinal field. Brain and lung image of patient are distorted with salt and pepper noise is caused by moving the head and chest during scanning process of patients. Reconstruction of these images is a most significant field of diagnostic evaluation and is produced clearly through techniques such as linear or non-linear filtering. However, restored images are produced with smaller amount of noise reduction in the presence of huge magnitude of salt and pepper noises. To eliminate the high density of salt and pepper noises from the reproduction of images, a new efficient fuzzy based median filtering algorithm with a moderate elapsed time is proposed in this paper. Reproduction image results show enhanced performance for the proposed algorithm over other available noise reduction filtering techniques in terms of peak signal -to -noise ratio (PSNR), mean square error (MSE), root mean square error (RMSE), mean absolute error (MAE), image enhancement factor (IMF) and structural similarity (SSIM) value when tested on different medical images like magnetic resonance imaging (MRI) and computer tomography (CT) scan brain image and CT scan lung image. The introduced algorithm is switching filter that recognize the noise pixels and then corrects them by using median filter with fuzzy two-sided π- membership function for extracting the local information.

• Journal of Korea Multimedia Society
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• v.5 no.5
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• pp.494-504
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• 2002

Volume rendering is a method of displaying volumetric data as a sequence two-dimensional image. Because this algorithm has an advantage of visualizing structures within objects, it has recently been used to analyze medical images i.e, MRI, PET, and SPECT. In this paper. we suggested a method for creating images easily from sampled volumetric data and applied the interpolation method to medical images. Additionally, we implemented and applied two kinds of interpolation methods to improve the image quality, linear interpolation and cubic interpolation at the sampling stage. Subsequently, we compared the results of volume rendered data using a transfer function. We anticipate a significant contribution to diagnosis through image reconstruction using a volumetric data set, because volume rendering techniques of medical images are the result of 3-dimensional data.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 2009.11a
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• pp.99-102
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• 2009

본 연구에서는 실제 기증받은 시체를 이용하여 인체의 각 구조물을 실제 모습 그대로 3D 이미지화하는 과정에 대해 알아보았다. 인체의 구조물을 3D 로 이미지화하는 과정은 다음과 같다. 먼저 시체를 0.2mm 간격으로 절단하여 절단면의 사진을 찍은 후, 각 절단면의 사진에서 각각의 구조물을 구역화하여 색칠을 한 후, 구역화한 이미지에서 외곽선을 추출하여 벡터 이미지를 만든다. 이 외곽선을 1mm 간격으로 쌓아 올린 후 그 표면을 재구성하여 3D 이미지로 변환하는 과정으로 진행되었다. 3D 이미지의 제작은 가슴 부위에 한정하여 이루어졌다. 인체의 해부학적인 모형을 3D 이미지로 시각화함으로써 얻는 효과는 일반인을 대상으로 인체의 내부에 대한 시각적인 호기심을 충족시켜주고 의학 상식을 넓히는데 도움을 줄 수 있을 것 이다. 또한 의대생들을 비롯한 의학 전문가들에게는 생생한 해부학 강의용으로도 활용 가능하다. 향후 Haptic 시스템을 이용한 의료 실습 어플리케이션과 접목될 수도 있을것이고, fMRI 데이터를 비롯한 타 데이터와의 융합을 통해 시각화하여 서비스 할 수도 있다. 이처럼 인체의 3D 모형은 의료분야에서 광범위하게 활용될 수 있는 데이터로써 그 가치를 지닐 것이다.

• Journal of Korean Neurosurgical Society
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• v.29 no.2
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• pp.255-260
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• 2000

The authors report a posttraumatic syringomyelia in a 30-year-old man who has complained pain, weakness of upper arm and dissociation sensory loss since 2 months before. He was underwent by decompressive laminectomy from T12 to L1, reduction of encroached bony fragments, transpedicular screw fixation from T12 to L2 and posterolateral bony fusion due to burst fracture of L1 at other hospital 3 years ago. Preoperative spinal MRI was highly suggestive of wide-spread, multiseptated syringomyelia from C3 to thoracolumbar junction. We performed wide decompressive laminectomy from T10 to L2 and subarachnoid space reconstrucion composed of microdissection of meningeal fibrosis widely, iatrogenic meningocele formation with lefting the dura mater opened for treatment of spinal-spinal pressure dissociation. Clinical manifestations and radiological findings of the patient were improved after the operation. This technique was thought to be superior to shunting procedures in cases of wide-spread, multiseptated post-traumatic syringomyelia.

• Journal of the Korean Arthroscopy Society
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• v.13 no.2
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• pp.161-164
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• 2009

Irreducible knee dislocation is a rare injury and often need an open procedure with ligaments reconstruction. This report describes a case of arthroscopic treatment of a patient with traumatic knee dislocation unable to reduce in a closed method. MRI revealed incarceration of the medial collateral ligament and capsule in the medial compartment. And arthroscopic examination confirmed incarcerated medial capsuloligamentous structures which prevented the knee from reduction. Arthroscopic procedure without ligaments reconstruction was complete when the medial condyle was well visualized and the knee reduced. After 4 weeks of immobilization in extension, range of motion exercise and gradual increases in weight bearing was allowed. At the 3- year follow-up, mild laxity was remained but the patient did not have any discomfort of doing ADL activity and showed full range of motion of the knee.