• Journal of the Korean Society for Industrial and Applied Mathematics
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• 제20권3호
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• pp.175-202
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• 2016

Ultrasound imaging is a widely used tool for visualizing human body's internal organs and quantifying clinical parameters. Due to its advantages such as safety, non-invasiveness, portability, low cost and real-time 2D/3D imaging, diagnostic ultrasound industry has steadily grown. Since the technology advancements such as digital beam-forming, Doppler ultrasound, real-time 3D imaging and automated diagnosis techniques, there are still a lot of demands for image quality improvement, faster and accurate imaging, 3D color Doppler imaging and advanced functional imaging modes. In order to satisfy those demands, mathematics should be used properly and effectively in ultrasound imaging. Mathematics has been used commonly as mathematical modelling, numerical solutions and visualization, combined with science and engineering. In this article, we describe a brief history of ultrasound imaging, its basic principle, its applications in obstetrics/gynecology, cardiology and radiology, domestic-industrial products, contributions of mathematics and challenging issues in ultrasound imaging.

• 대한의용생체공학회:의공학회지
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• 제30권1호
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• pp.1-9
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• 2009

Many types of small animal imaging modalities, like micro-CT, micro-PET, and micro-SPECT, have been recently developed worldwide. Small animal imaging systems are now recognized as indispensable tools to validate efficacy and safety of new drugs or new therapeutic methods using the animal disease models. With increasing demands for small animal imaging in biomedical research, multimodal small animal imaging systems, like micro-PET/CT or micro PET/MRI, are now also being developed. Small animal imaging with spatial resolution and sensitivity comparable to human imaging is quite challenging since laboratory small animals are much smaller than human beings. Research activities in Korea on small animal imaging systems are reviewed in this paper. In the field of micro-CT and micro-PET, many world-class technologies have been developed successfully in Korea. It is expected that the developed animal imaging system technologies can be used in the development of clinical imaging systems in Korea in the near future.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1995년도 추계학술대회
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• pp.247-249
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• 1995

A new localized imaging technique of reduced imaging time using a locally-linear gradient is proposed. Since most fast MR imaging methods need the whole k-space data corresponding to the whole imaging area, there are limitations in reducing the minimum imaging time. The imaging method proposed in this paper uses a specially-made gradient coil generating a local ramp-shape field and uniform field outside of the imaging area. Conventional imaging sequences can be used without any RF/gradient pulse sequence modifications. The proposed localized imaging technique has been implemented on a 2.0 Tesla whole-body system at KAIST and the imaging results show the utility of the proposed technique.

• Nuclear Medicine and Molecular Imaging
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• 제43권3호
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• pp.165-173
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• 2009

Nuclear cardiology in Korea is less active, compared to nuclear oncology, but it has been specialized and ramified. Lately, sophisticated nuclear cardiac imaging methods provide more convenience for patients. It is necessary to accurately estimate the recent progress in the imaging devices for nuclear cardiology. Myocardial perfusion imaging is a well established study to evaluate heart function. Myocardial perfusion SPECT and PET have been used for assessment of coronary artery disease with various radiopharmaceuticals. And of late, the development of advanced imaging devices - multi-pinhole technique and high definition imaging technique - and software made the scanning time shorter and expanded the application field. Therefore, it is required to review the nuclear cardiology hardware/software for the clinical practice and research. In this review, the characteristics about recently-developed SPECT/PET and software for nuclear cardiology are described. It is hoped that this information would contribute to improving the activity of nuclear cardiac research in Korea where the research for the fusion imaging combining a and nuclear imaging is drawing more attention.

• Genomics & Informatics
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• 제5권2호
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• pp.46-55
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• 2007

The convergence of molecular and genetic disciplines with non-invasive imaging technologies has provided an opportunity for earlier detection of disease processes which begin with molecular and cellular abnormalities. This emerging field, known as molecular imaging, is a relatively new discipline that has been rapidly developed over the past decade. It endeavors to construct a visual representation, characterization, and quantification of biological processes at the molecular and cellular level within living organisms. One of the goals of molecular imaging is to translate our expanding knowledge of molecular biology and genomic sciences into good patient care. The practice of molecular imaging is still largely experimental, and only limited clinical success has been achieved. However, it is anticipated that molecular imaging will move increasingly out of the research laboratory and into the clinic over the next decade. Non-invasive in vivo molecular imaging makes use of nuclear, magnetic resonance, and in vivo optical imaging systems. Recently, an interest in Positron Emission Tomography (PET) has been revived, and along with optical imaging systems PET is assuming new, important roles in molecular genetic imaging studies. Current PET molecular imaging strategies mostly rely on the detection of probe accumulation directly related to the physiology or the level of reporter gene expression. PET imaging of both endogenous and exogenous gene expression can be achieved in animals using reporter constructs and radio-labeled probes. As increasing numbers of genetic markers become available for imaging targets, it is anticipated that a better understanding of genomics will contribute to the advancement of the molecular genetic imaging field. In this report, the principles of non-invasive molecular genetic imaging, its applications and future directions are discussed.

• Korean Journal of Radiology
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• 제25권1호
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• pp.86-102
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• 2024

Early diagnosis, accurate assessment, and localization of peritoneal metastasis (PM) are essential for the selection of appropriate treatments and surgical guidance. However, available imaging modalities (computed tomography [CT], conventional magnetic resonance imaging [MRI], and 18fluorodeoxyglucose positron emission tomography [PET]/CT) have limitations. The advent of new imaging techniques and novel molecular imaging agents have revealed molecular processes in the tumor microenvironment as an application for the early diagnosis and assessment of PM as well as real-time guided surgical resection, which has changed clinical management. In contrast to clinical imaging, which is purely qualitative and subjective for interpreting macroscopic structures, radiomics and artificial intelligence (AI) capitalize on high-dimensional numerical data from images that may reflect tumor pathophysiology. A predictive model can be used to predict the occurrence, recurrence, and prognosis of PM, thereby avoiding unnecessary exploratory surgeries. This review summarizes the role and status of different imaging techniques, especially new imaging strategies such as spectral photon-counting CT, fibroblast activation protein inhibitor (FAPI) PET/CT, near-infrared fluorescence imaging, and PET/MRI, for early diagnosis, assessment of surgical indications, and recurrence monitoring in patients with PM. The clinical applications, limitations, and solutions for fluorescence imaging, radiomics, and AI are also discussed.

• Korean Journal of Radiology
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• 제22권2호
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• pp.243-252
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• 2021

Objective: To compare and correlate the findings of intravoxel incoherent motion (IVIM) magnetic resonance (MR) imaging and arterial spin labeling (ASL) imaging in characterizing parotid gland tumors. Materials and Methods: We retrospectively reviewed 56 patients with parotid gland tumors evaluated by MR imaging. The true diffusion coefficient (D), pseudo-diffusion coefficient (D^*), and fraction of perfusion (f) values of IVIM imaging and tumor-to-parotid gland signal intensity ratio (SIR) on ASL imaging were calculated. Spearman rank correlation coefficient, chi-squared, Mann-Whitney U, and Kruskal-Wallis tests with the post-hoc Dunn-Bonferroni method and receiver operating characteristic curve assessments were used for statistical analysis. Results: Malignant parotid gland tumors showed significantly lower D than benign tumors (p = 0.019). Within subgroup analyses, pleomorphic adenomas (PAs) showed significantly higher D than malignant tumors (MTs) and Warthin's tumors (WTs) (p < 0.001). The D^* of WTs was significantly higher than that of PAs (p = 0.031). The f and SIR on ASL imaging of WTs were significantly higher than those of MTs and PAs (p < 0.05). Significantly positive correlation was found between SIR on ASL imaging and f (r = 0.446, p = 0.001). In comparison with f, SIR on ASL imaging showed a higher area under curve (0.853 vs. 0.891) in discriminating MTs from WTs, although the difference was not significant (p = 0.720). Conclusion: IVIM and ASL imaging could help differentiate parotid gland tumors. SIR on ASL imaging showed a significantly positive correlation with f. ASL imaging might hold potential to improve the ability to discriminate MTs from WTs.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
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• pp.453-456
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• 2009

We present a new generation of imaging colorimeter that ensures improved accuracy and sensitivity for shorter measurement times. The imaging optics is telecentric on the sensor and allows measurements at any distances without additional calibration. A new technology is used to make the color filters and flat densities. Imaging polarimetry at fixed wavelength is also possible with the same instrument.

• Investigative Magnetic Resonance Imaging
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• 제3권1호
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• pp.13-19
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• 1999

MRI imaging provides many benefits such as noninvasive, 3-dimensional imaging capabilities. But it has relatively serious drawback that is the long data collection time, compared with other imaging modality. Many studies have been performed for fast MR imaging. But EPI and SEPI (4-6) are required to expensive hardware. In this paper, we introduce to Burst imaging technique. It can reduce imaging time by use of a mulitple RF excitation technique. Further it is easily implemented to the normal MRI system. But a pixel profile in the conventional burst sequence is so poor that excited area by burst sequence is a small portion of a pixel. This causes poor signal to noise ratio in burst image. therefore frequency sweeping of RF pulse for burst imaging sequence is proposed to improve pixel profile. A burst pulse train is shaped by liner or nonlinear frequency sweeping function so that all the spins within a pixel are excited, thereby improving the signal to noise ratio. It also shows that the pixel profiles are dependent on how frequency sweep is made. Computer simulations with Bloch equation and experimental results obtained using a 1.0 T NMR imaging system are presented.

• 대한핵의학회지
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• 제38권2호
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• pp.143-151
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• 2004

Recent progress in the development of non-invasive imaging technologies continues to strengthen the role of molecular imaging biological research. These tools have been validated recently in variety of research models, and have been shown to provide continuous quantitative monitoring of the location(s), magnitude, and time-variation of gene expression. This article reviews the principles, characteristics, categories and the use of radionuclide reporter gene imaging technologies as they have been used in imaging cell trafficking, imaging gene therapy, imaging endogenous gene expression and imaging molecular interactions. The studios published to date demonstrate that reporter gene imaging technologies will help to accelerate pre-clinical model validation as well as allow for clinical monitoring of human diseases.