• Proceedings of the KOSOMBE Conference
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• v.1998 no.11
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• pp.283-284
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• 1998

The Virtual Reality Technology makes you feel like you are in the situation which has been made up by using the information inputted through the device which is connected with the body part. If the image which is taken from CT, MRI is reorganized in 3D, it can present the shape of the human organ more clearly. So It is more likely to be used in the operation which needs the diversified examination about mutual relation with each part in a place of 3D or confirmation of the planed information. We developed the Technology which can reorganize the image from the CT into the 3D data and represent the 3D movement of the finger according to the hand.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2010.07a
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• pp.267-269
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• 2010

3D 모니터의 공급으로 IT영역 및 의료영상 분야 에서도 3D 영상에 관한 산업 발달이 화두가 되고 있다. 의료영상은 CT, MRI 영상의 정확한 판독이 필요하기 때에 2D 의료영상보다 구체적인 3D 정보를 얻을 수 있는 3D 입체영상에 관심이 높아지고 있다. 본 논문에서는 3D 의료 촬영기계가 아닌 기존의 2D 의료 평면 영상 한 장만을 이용한 3D 입체영상을 제작하는 방법을 제안한다. 실험 영상으로 CT의 2D 의료영상을 사용한다. 장기의 영역 분할을 한후, 각 장기 성분을 분석한다. 분리 한 장기들은 명암값에 의해 구분 되며, 이를 바탕으로 영상의 깊이 정보를 추출한다. 추출한 정보로 깊이맵을 작성한다. 작성된 깊이 맵과 기본 2D 의료영상과 합성, 깊이를 할당하여 3D영상을 구현한다.

• Investigative Magnetic Resonance Imaging
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• v.13 no.1
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• pp.9-14
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• 2009

T1-, and T2-weighted imagings and FLAIR (fluid attenuated inversion recovery) imaging are fundamental imaging methods in the brain. T1-weighted imaging is a spin-echo sequence with short TR and short TE and produces the tissue contrast by different T1 relaxation times. In other words, short TR maximizes the difference of the longituidinal magnetization recovery between the tissues. T2-weighted imaging is a spin-echo sequence with long TR and long TE and produces the tissue contrast by different T2 relaxation times. Long TE maximizes the difference of the transverse magnetization decay between the tissues. FLAIR is an inversion recovery sequence using 180 degree inversion pulse. 2500 msec of inversion time is applied to suppress the CSF signal.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.28 no.11
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• pp.1664-1671
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• 2004

It is necessary to have a model that describes the feature of the knee Joint with a sufficient accuracy. Koreans, however, do not have their own knee joint model to be used in the total knee replacement arthroplasty. They have to use European or American models which do not match Koreans. Three-dimensional visualization techniques are found to be useful in a wide range of medical applications. Three-dimensional imaging studies such as CT(computed tomography) and MRI(magnetic resonance image) provide the primary source of patient-specific data. Three-dimensional knee joint models were constructed by image processing of the CT data of 10 subjects. Using the constructed model, the dimensions of Korean knee joint were measured. And this study proposed a three-dimensional model and data, which can be helpful to develop Korean knee implants and to analyze knee joint movements.

• Proceedings of the Korean Information Science Society Conference
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• 2012.06c
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• pp.359-361
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• 2012

본 논문은 T2강조 MR 영상과 확산강조 MR 영상의 강체 정합을 통해 크기, 위치, 회전 변환 왜곡을 보정하여 자궁내막암의 위치를 자동으로 찾는 방법을 제안한다. 영상해상도와 밝기값 분포가 서로 다른 두 영상간 정합의 정확성을 향상시키기 위해 잡음을 제거하고 두 영상의 밝기값 신호 분포의 유사성을 강화시킨다. 유사성이 향상된 두 영상의 크기, 위치, 회전 변환 왜곡을 보정하기 위해 정규화 상호정보를 최대화 하는 강체 정합을 반복적으로 수행한다. 정합된 영상에서 악성 종양을 쉽게 판별 할 수 있도록 현상확상계수지도를 컬러맵으로 생성하여 T2강조 MR 영상에서 얻은 종양의 후보군에 매핑하여 T2강조 MR 영상과 융합한다. 실험을 위하여 최적화 반복 과정에 따른 정규화 상호정보 수치 수렴 과정을 확인하고, 융합 후 종양 영역이 매핑되는 것을 육안평가를 통해 분석하였다. 제안방법을 통하여 T2강조 MR 영상과 확산강조 MR 영상을 융합함으로써 종양의 위치를 자동으로 파악하고 자궁내막암의 병기를 확정하는 용도로 활용할 수 있다.

• The Korean Journal of Nuclear Medicine Technology
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• v.19 no.1
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• pp.12-16
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• 2015

Purpose Principal component analysis (PCA) is a method often used in the neuroimagre analysis as a multivariate analysis technique for describing the structure of high dimensional correlation as the structure of lower dimensional space. PCA is a statistical procedure that uses an orthogonal transformation to convert a set of observations of correlated variables into a set of values of linearly independent variables called principal components. In this study, in order to investigate the usefulness of PCA in the brain PET image analysis, we tried to analyze C[11]-PIB PET image as a representative case. Materials and Methods Nineteen subjects were included in this study (normal = 9, AD/MCI = 10). For C[11]-PIB, PET scan were acquired for 20 min starting 40 min after intravenous injection of 9.6 MBq/kg C[11]-PIB. All emission recordings were acquired with the Biograph 6 Hi-Rez (Siemens-CTI, Knoxville, TN) in three-dimensional acquisition mode. Transmission map for attenuation-correction was acquired using the CT emission scans (130 kVp, 240 mA). Standardized uptake values (SUVs) of C[11]-PIB calculated from PET/CT. In normal subjects, 3T MRI T1-weighted images were obtained to create a C[11]-PIB template. Spatial normalization and smoothing were conducted as a pre-processing for PCA using SPM8 and PCA was conducted using Matlab2012b. Results Through the PCA, we obtained linearly uncorrelated independent principal component images. Principal component images obtained through the PCA can simplify the variation of whole C[11]-PIB images into several principal components including the variation of neocortex and white matter and the variation of deep brain structure such as pons. Conclusion PCA is useful to analyze and extract the main pattern of C[11]-PIB image. PCA, as a method of multivariate analysis, might be useful for pattern recognition of neuroimages such as FDG-PET or fMRI as well as C[11]-PIB image.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.7
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• pp.4704-4710
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• 2015

The purpose of this study is to obtain a useful diagnostic image by increasing the signal strength of the peripheral artery, was to use a T1 shortening effect of gadolinium contrast agents to improve the disadvantages of the phase image. From october to december 2014 thirty patients were underwent the MRI scanning, except for heart disease. Research method was evaluated comparing the image after gadolinium contrast MR image acquisition step before evaluating the difference between the signal intensity for T1 shortening effect. In frontal lobe 19.45%, temporal lobe 23.09%, occipital lobe 25.45%, parietal lobe 18.82%, cerebellum 20.93% after peripheral arterial signal strength results of gadolinium contrast agent injection was increased significantly after injection of gadolinium both statistically significant. After injecting a contrast agent gadolinium in SWI by increasing the signal strength of the T1 shortening effect can be obtained when using the phase image to give a useful image in diagnosis and treatment.

• Progress in Medical Physics
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• v.13 no.4
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• pp.209-217
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• 2002

There have been many studies on the application of the reciprocal advantages of multimodality image to define accurate target volume in the Process of radiation treatment planning. For the proper use of the multimodality images, the registration works between different modality images should be performed in advance. In this study, we selected chamfer matching method and mutual information method as most popular methods in recent image registration studies considering the registration accuracy and clinical practicality. And the two registration methods were analyzed to deduce the optimal registration method according to the characteristics of images. Lung phantom of which multimodality images could be acquired was fabricated and CT, MRI and SPECT images of the phantom were used in this study. We developed the registration program which can perform the two registration methods properly and analyzed the registration results which were produced by the developed program in many different images' conditions. Although the overall accuracy of the registration in both chamfer matching method and mutual information method was acceptable, the registration errors in SPECT images which had lower resolution and in degraded images of which data were removed in some part were increased when chamfer matching method was applied. Especially in the case of degraded reference image, chamfer matching methods produce relatively large errors compared with mutual information method. Mutual information method can be estimated as more robust registration method than chamfer matching method in this study because it did not need the prerequisite works, the extraction of accurate contour points, and it produced more accurate registration results consistently regardless of the images' characteristics. The analysis of the registration methods in this study can be expected to provide useful information to the utilization of multimodality images in delineating target volume for radiation treatment planning and in many other clinical applications.

• Investigative Magnetic Resonance Imaging
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• v.6 no.2
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• pp.129-136
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• 2002

Purpose : To evaluate the usefulness of MRCP in the diagnosis of the variable causes of common bile duct(CBD) dilatation, except stone or tumor Materials and methods : Twenty-six patients(M:F=15:11, mean age; 62 years) with both MRCP and ERCP were included in this study. Dynamic MRCP(n=12) and contrast-enhanced MRI(n=10) of abdomen were also added. Dilatation of CBD, intrahepatic ducts and pancreatic duct was evaluated, including coexistence of intrahepatic ductal stone, pancreatic pseudocyst, and papillary or papillary edema. The criteria of CBD dilatation was over than 7mm(n= 21, without cholecystectomy) or 10 mm(n=5, with cholecystecto-my) in diameter on T2-weighted coronal image. Results : The mean diameter of CBD was 12.7mm without cholecystectomy(9-19 mm) and 13.0 mm with cholecystectomy(10-15mm), respectively(p 〉0.05). Cholangitis(n=11, 42.3%), chronic pancreatitis(n=8, 30.8%), stenosis of distal CBD(n= 6, 23.1%), periampullary diverticulum(n=3, 11.5%), stenosis of ampulla of Vater(n=2, 7.7%), dysfunction of sphincter of Oddi(n=2, 7.7%), acute focal pancreatitis in the pancreatic head(n=2, 7.7%), papillitis(n=1, 3.8%), pseudocyst in the pancre atic head(n = 1, 3.8%), and ascaris in CBD(n=1, 3.8%) were noted. Pancreatic duct dilatation(n=10, 38.5%) and duodenal diverticulum(n=3, 11.5%) were also seen on MRC P. On dynamic MRCP(12 patients), distal CBD was visualized in 2 patients(16.7%), which was not shown on routine MRCP. Only 1 patient(10.0%) showed papillitis with slightly enhancing papilla on contrast-enhanced MRI (10 patients). Conclusion : MRCP was thought to be helpful in the evaluation of the causes of CBD dilatation, not caused by stone or tumor, especially in the cases of stenosis of distal CBD and chronic pancreatitis, dysfunction of sphincter of Oddi on dynamic MRCP and cholangitis and pericholangitic abnormality on contrast-enhanced MRI.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.29 no.2
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• pp.407-410
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• 1999

Purpose; To find out the best imaging parameters for the diagnosis of disc in MRI imaging. Materials and methods; The diagnostic quality of the disc among the Tl, PD and T2 images of same patients02 joints, 223 images) was compared by visual(I-IV grades) and gray level measurement (pre- and infra-discal area) method. Results; PD images showed best results with 43.7％ of the images belonging to grade III (good) and with statistically significant higher difference of the gray levels at pre- and infra-discal areas. But there were no grade N (excellent) images. Conclusions; PD images are best method among Tl. PD and T2 images in diagnosing the disc but since there were no excellent images further imaging parameters should be studied for better images.