• Title/Summary/Keyword: CHESS technique

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A Comparative Quantitative Analysis of IDEAL (Iterative Decomposition of Water and Fat with Echo Asymmetry and Least Squares Estimation) and CHESS (Chemical Shift Selection Suppression) Technique in 3.0T Musculoskeletal MRI

  • Kim, Myoung-Hoon;Cho, Jae-Hwan;Shin, Seong-Gyu;Dong, Kyung-Rae;Chung, Woon-Kwan;Park, Tae-Hyun;Ahn, Jae-Ouk;Park, Cheol-Soo;Jang, Hyon-Chol;Kim, Yoon-Shin
    • Journal of Magnetics
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    • v.17 no.2
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    • pp.145-152
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    • 2012
  • Patients who underwent hip arthroplasty using the conventional fat suppression technique (CHESS) and a new technique (IDEAL) were compared quantitatively to assess the effectiveness and usefulness of the IDEAL technique. In 20 patients who underwent hip arthroplasty from March 2009 to December 2010, fat suppression T2 and T1 weighted images were obtained on a 3.0T MR scanner using the CHESS and IDEAL techniques. The level of distortion in the area of interest, the level of the development of susceptibility artifacts, and homogeneous fat suppression were analyzed from the acquired images. Quantitative analysis revealed the IDEAL technique to produce a lower level of image distortion caused by the development of susceptibility artifacts due to metal on the acquired images compared to the CHESS technique. Qualitative analysis of the anterior area revealed the IDEAL technique to generate fewer susceptibility artifacts than the CHESS technique but with homogeneous fat suppression. In the middle area, the IDEAL technique generated fewer susceptibility artifacts than the CHESS technique but with homogeneous fat suppression. In the posterior area, the IDEAL technique generated fewer susceptibility artifacts than the CHESS technique. Fat suppression was not statistically different, and the two techniques achieved homogeneous fat suppression. In conclusion, the IDEAL technique generated fewer susceptibility artifacts caused by metals and less image distortion than the CHESS technique. In addition, homogeneous fat suppression was feasible. In conclusion, the IDEAL technique generates high quality images, and can provide good information for diagnosis.

Evaluation of Usefulness of IDEAL(Iterative decomposition of water and fat with echo asymmetry and least squares estimation) Technique in 3.0T Breast MRI (3.0T 자기공명영상을 이용한 유방 검사시 IDEAL기법의 유용성 평가)

  • Cho, Jae-Hwan
    • Journal of Digital Contents Society
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    • v.11 no.2
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    • pp.217-224
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    • 2010
  • The purpose of this study was to examine the usefulness of IDEAL technique in breast MRI by performing a quantitative comparative analysis in patients diagnosed with DCIS. On a 3.0T MR scanner, fat-suppressed T2-weighted images and T1-weighted images before and after contrast enhancement were obtained from 20 patients histologically diagnosed with ductal carcinoma in situ (DCIS). The findings from the quantitative image analysis are the following: 1) On T2-weighted images, SNR were not significantly different in the lesion area itself between the CHESS and IDEAL groups, while the IDEAL group showed higher SNR at the ductal area and fat area than the CHESS group. In addition, the CNR were higher for the IDEAL group in those regions. 2) On T1-weighted images before enhancement, SNR were not significantly different in the lesion area itself between the CHESS and IDEAL groups, while the IDEAL group showed higher SNR at the ductal area and fat area than the CHESS group. In addition, the CNR were higher for the IDEAL group in those regions. 3) On T1-weighted images after enhancement, SNR were not significantly different in the lesion area itself between the CHESS and IDEAL groups, while the IDEAL group showed higher SNR at the ductal area and fat area than the CHESS group.

Quantitative Evaluation of Optimized Fat-Suppression Techniques for T1 Weighted Cervical Spine MR Imaging: Comparison of TSE-CHESS and TSE-SPAIR (T1 강조 경추자기공명영상에 대한 최적의 지방소거기법의 정량적 평가: TSE-CHESS 과 TSE-SPAIR 의 비교)

  • Goo, Eun-Hoe
    • Journal of Digital Convergence
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    • v.11 no.11
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    • pp.529-536
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    • 2013
  • The purpose of this study is to know clinical usefulness for fat suppression of the body curved portion compared with TSE-CHESS and TSE-SPAIR technique. A total of 25 normal volunteers without cervical spine disease were studied on a 3.0 T MRI scanner. As a quantitative analysis, PSNRs and CNRs were evaluated by using two methods for fat suppression of the body curved portion. As a results, PSNRs and CNRs for fat suppression were significantly greater for the TSE-SPAIR technique compared to TSE-CHESS technique. In conclusion, this study showed that a TSE-SPAIR technique has improved PSNRs and CNRs for evaluating of fat suppression in the body curved portion. These conclusions in the future will be provided information in diagnosis of fat suppression for the body curved portion.

The clinical usefulness of fat suppression by chemical shift selective(CHESS) pulse in MRI (MRI에서 화학적 이동 선택(CHESS) pulse에 의한 지방소거의 임상적 유용성)

  • Han, Man-Seok;Yang, Hae-Sool;Jin, Kyung-Soo;Eo, Ik-Soo;Cho, Dong-Heon
    • The KIPS Transactions:PartB
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    • v.14B no.6
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    • pp.431-436
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    • 2007
  • Magnetic Resonance Imaging(MRI) has chemical shift phenomenon between fat and water, and the phenomenon has influence on structure enclosed by fat. Strong signals emitted from fat often generate false artefact, which reflects the importance of fat suppression techniques. There have been a number of researches on fat suppression techniques, but using fat suppression method alone in MRI can cause difficultproblems in diagnosis. This paper aims to study a fat suppression method by Chemical Shift Selective saturation(CHESS). This research describes the theoretical background and the experiment on water and fat phantom with MR instruments. In the experiment, CHESS pulse was designed by utilising Matlap program, and the pulse diagram was generated for the Pre-saturation process. The experiment using water and fat phantom was applied to C-spine, L-spine and Breast, and produced successful fat suppression results. This experiment has proved that the CHESSpulse fat suppression is a very helpful technique in diagnosing medical imaging. This method is a robust and useful technique for both clinical and basic investigators..(Experiment with Chungnam national university hospital G.E 1.5T MR)

Evaluation of Selective Saturation and Refocousing Pulses in Chemical Shift NMR Imaging

  • Shin, Yong-Jin;Park, Young-Sik
    • Journal of the Korean Magnetic Resonance Society
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    • v.4 no.1
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    • pp.64-73
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    • 2000
  • There are several methods to achieve selective NMR image of differing chemical species with the three most popular methods of Dixon's, CHESS, and SECSI. A major problem common to all chemical shift imaging methods is the uniformity of the static magnetic field and distortions introduced when RF coils are loaded with a conducting specimen. Without magnetic field shimming, these methods cannot be used to acquire selectively image protons in fat and water which are separated by approximately 3.0ppm. Experiments with a phantom, with linewidths of 2.5 to 3.5ppm, were quantitatively evaluated for the three methods and a new chemical shift imaging method. In this study the new chemical shift imaging method (modified CHESS+SECSI technique) which included a selective saturation and refocusing pulse, was developed to determine the ratios of water and fat in different samples.

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Advanced Improvement for Frequent Pattern Mining using Bit-Clustering (비트 클러스터링을 이용한 빈발 패턴 탐사의 성능 개선 방안)

  • Kim, Eui-Chan;Kim, Kye-Hyun;Lee, Chul-Yong;Park, Eun-Ji
    • Journal of Korea Spatial Information System Society
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    • v.9 no.1
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    • pp.105-115
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    • 2007
  • Data mining extracts interesting knowledge from a large database. Among numerous data mining techniques, research work is primarily concentrated on clustering and association rules. The clustering technique of the active research topics mainly deals with analyzing spatial and attribute data. And, the technique of association rules deals with identifying frequent patterns. There was an advanced apriori algorithm using an existing bit-clustering algorithm. In an effort to identify an alternative algorithm to improve apriori, we investigated FP-Growth and discussed the possibility of adopting bit-clustering as the alternative method to solve the problems with FP-Growth. FP-Growth using bit-clustering demonstrated better performance than the existing method. We used chess data in our experiments. Chess data were used in the pattern mining evaluation. We made a creation of FP-Tree with different minimum support values. In the case of high minimum support values, similar results that the existing techniques demonstrated were obtained. In other cases, however, the performance of the technique proposed in this paper showed better results in comparison with the existing technique. As a result, the technique proposed in this paper was considered to lead to higher performance. In addition, the method to apply bit-clustering to GML data was proposed.

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$^{19}F$ MR Imaging of 5-FU Metabolism in Mice

  • Chaejoon Cheong;Lee, Seung-C.;Jae-G. Seo;Kim, Sung W.;Lee, Chulhyun;Kim, Chul S.;Taegyun Yang
    • Journal of the Korean Magnetic Resonance Society
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    • v.5 no.2
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    • pp.110-117
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    • 2001
  • $^{19}$ F imaging of mice was carried out. For $^{19}$ F imaging, 5-flouro-uracil (5-FU) was injected into a mouse and in vivo detection of the catabolism of 5-FU to a-fluoro-P-alanine (FBAL) was carried out. The chemical shift selective (CHESS) imaging technique was employed. The 19F spectra and images give temporal and spatial information of the metabolism for 5-FU in mice.

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CHEMICAL SHIFT IMAGING

  • Yi, Yun;Kim, Min-Gi
    • Proceedings of the KOSOMBE Conference
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    • v.1992 no.11
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    • pp.22-25
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    • 1992
  • Lipid component and water component image in living organism can be acquired due to its chemical shift difference. Various techniques for chemical shift imaging were used for acquiring separated image. It is necessary two imaging experiments to acquire two separated images wi th Dixon's method. This technique is less susceptible to local magnetic inhomogeneities and easily applied to multi-slice imaging. With CHESS and SECSI method, which based on chemical selectivity of R.F pusle, either water or lipid image can be acquired by one imaging experiment. However, those are more susceptible to local magnetic field inhomogeneities and difficult to apply to multi-slice imaging. The SECSI method showed best signal suppression ratio of fat and water, which is measure of separation of water and fat.

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Feasibility of Deep Learning Algorithms for Binary Classification Problems (이진 분류문제에서의 딥러닝 알고리즘의 활용 가능성 평가)

  • Kim, Kitae;Lee, Bomi;Kim, Jong Woo
    • Journal of Intelligence and Information Systems
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    • v.23 no.1
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    • pp.95-108
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    • 2017
  • Recently, AlphaGo which is Bakuk (Go) artificial intelligence program by Google DeepMind, had a huge victory against Lee Sedol. Many people thought that machines would not be able to win a man in Go games because the number of paths to make a one move is more than the number of atoms in the universe unlike chess, but the result was the opposite to what people predicted. After the match, artificial intelligence technology was focused as a core technology of the fourth industrial revolution and attracted attentions from various application domains. Especially, deep learning technique have been attracted as a core artificial intelligence technology used in the AlphaGo algorithm. The deep learning technique is already being applied to many problems. Especially, it shows good performance in image recognition field. In addition, it shows good performance in high dimensional data area such as voice, image and natural language, which was difficult to get good performance using existing machine learning techniques. However, in contrast, it is difficult to find deep leaning researches on traditional business data and structured data analysis. In this study, we tried to find out whether the deep learning techniques have been studied so far can be used not only for the recognition of high dimensional data but also for the binary classification problem of traditional business data analysis such as customer churn analysis, marketing response prediction, and default prediction. And we compare the performance of the deep learning techniques with that of traditional artificial neural network models. The experimental data in the paper is the telemarketing response data of a bank in Portugal. It has input variables such as age, occupation, loan status, and the number of previous telemarketing and has a binary target variable that records whether the customer intends to open an account or not. In this study, to evaluate the possibility of utilization of deep learning algorithms and techniques in binary classification problem, we compared the performance of various models using CNN, LSTM algorithm and dropout, which are widely used algorithms and techniques in deep learning, with that of MLP models which is a traditional artificial neural network model. However, since all the network design alternatives can not be tested due to the nature of the artificial neural network, the experiment was conducted based on restricted settings on the number of hidden layers, the number of neurons in the hidden layer, the number of output data (filters), and the application conditions of the dropout technique. The F1 Score was used to evaluate the performance of models to show how well the models work to classify the interesting class instead of the overall accuracy. The detail methods for applying each deep learning technique in the experiment is as follows. The CNN algorithm is a method that reads adjacent values from a specific value and recognizes the features, but it does not matter how close the distance of each business data field is because each field is usually independent. In this experiment, we set the filter size of the CNN algorithm as the number of fields to learn the whole characteristics of the data at once, and added a hidden layer to make decision based on the additional features. For the model having two LSTM layers, the input direction of the second layer is put in reversed position with first layer in order to reduce the influence from the position of each field. In the case of the dropout technique, we set the neurons to disappear with a probability of 0.5 for each hidden layer. The experimental results show that the predicted model with the highest F1 score was the CNN model using the dropout technique, and the next best model was the MLP model with two hidden layers using the dropout technique. In this study, we were able to get some findings as the experiment had proceeded. First, models using dropout techniques have a slightly more conservative prediction than those without dropout techniques, and it generally shows better performance in classification. Second, CNN models show better classification performance than MLP models. This is interesting because it has shown good performance in binary classification problems which it rarely have been applied to, as well as in the fields where it's effectiveness has been proven. Third, the LSTM algorithm seems to be unsuitable for binary classification problems because the training time is too long compared to the performance improvement. From these results, we can confirm that some of the deep learning algorithms can be applied to solve business binary classification problems.