• Progress in Medical Physics
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• v.12 no.1
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• pp.41-50
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• 2001

The quantification analysis of renal scintigraphy is strongly affected by the location, shape and size of region of interest(ROI). When ROIs are drawn manually, these ROIs are not reproducible due to the operators' subjective point of view, and may lead to inconsistent results even if the same data were analyzed. In this study, the effect of the ROI variation on the analysis of renal scintigraphy when the ROIs are drawn manually was investigated, and in order to obtain more consistent results, methods for automated ROI definition were developed and the results from the application of the developed methods were analyzed. Relative renal function, glomerular filtration rate and mean transit time were selected as clinical parameters for the analysis of the effect of ROI and the analysis tools were designed with the programming language of IDL5.2. To obtain renal scintigraphy, $^{99m}$Tc-DTPA was injected to the 11 adults of normal condition and to study the inter-operator variability, 9 researchers executed the analyses. The calculation of threshold using the gradient value of pixels and border tracing technique were used to define renal ROI and then the background ROI and aorta ROI were defined automatically considering anatomical information and pixel value. The automatic methods to define renal ROI were classified to 4 groups according to the exclusion of operator's subjectiveness. These automatic methods reduced the inter-operator variability remarkably in comparison with manual method and proved the effective tool to obtain reasonable and consistent results in analyzing the renal scintigraphy quantitatively.

• Journal of the Institute of Electronics and Information Engineers
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• v.52 no.8
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• pp.132-139
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• 2015

Visual SLAM(Simultaneous Localization And Mapping) has been used widely to estimate a mobile robot's location. Visual SLAM estimates relative motions with static visual features over image sequence. Because visual SLAM methods assume generally static features in the environment, we cannot obtain precise results in dynamic situation including many moving objects: cars and human beings. This paper presents a stereo vision based SLAM method in dynamic environment. First, we extract disparity map with stereo vision and compute optical flow. We then compute disparity change that is the estimated flow field between stereo views. After examining the disparity change value, we detect ROIs(Region Of Interest) in disparity space to determine dynamic scene objects. In indoor environment, many structural planes like walls may be determined as false dynamic elements. To solve this problem, we segment the scene into planar structure. More specifically, disparity values by the stereo vision are projected to X-Z plane and we employ Hough transform to determine planes. In final step, we remove ROIs nearby the walls and discriminate static scene elements in indoor environment. The experimental results show that the proposed method can obtain stable performance in dynamic environment.

• The Korean Journal of Nuclear Medicine
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• v.23 no.2
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• pp.155-163
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• 1989

Regional cerebral perfusion was evaluated in 15 normal controls by single photon emission computed tomography using $^{99m}Tc$ HM-PAO. For quantitative analysis, 13 pairs of homologous region of interest (ROI) were drawn on three transverse slices matching the vascular territories and cerebral cortices, and normal values of 3 semiqunatitative indices including 'Right to left ratio'(R/L ratio), 'Regional index'(RI), and 'Region to cerebellum ratio'(R/cbll ratio) were calculated. Mean values of R/L ratios of homotogous regions were ranged from 0.985 to 1.023, and mean ${\pm}2$ s.d. of all regions did not exceed 11% of mean. Significant difference of RIs (mean count per voxel of a ROI/mean count per voxel of total ROIs) between regions were found (p<0.001) with highest values in occipital cortex and cerebellum. After attenuation correction, RIs in deep gray, cranial portion of anterior cerebral artery and vascular territories in the 2nd slice increased significantly (p < 0.05-0.001), but vise versa in other ROIs. Region to cerebellum ratios also showed regional difference similar to RIs.

• The Korean Journal of Nuclear Medicine
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• v.37 no.3
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• pp.162-170
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• 2003

The probabilistic anatomical maps are used to localize the functional neuro-images and morphological variability. The quantitative indicator is very important to inquire the anatomical position of an activated legion because functional image data has the low-resolution nature and no inherent anatomical information. Although previously developed MNI probabilistic anatomical map was enough to localize the data, it was not suitable for the Korean brains because of the morphological difference between Occidental and Oriental. In this study, we develop a probabilistic anatomical map for Korean normal brain. Normal 75 blains of T1-weighted spoiled gradient echo magnetic resonance images were acquired on a 1.5-T GESIGNA scanner. Then, a standard brain is selected in the group through a clinician searches a brain of the average property in the Talairach coordinate system. With the standard brain, an anatomist delineates 89 regions of interest (ROI) parcellating cortical and subcortical areas. The parcellated ROIs of the standard are warped and overlapped into each brain by maximizing intensity similarity. And every brain is automatically labeledwith the registered ROIs. Each of the same-labeled region is linearly normalize to the standard brain, and the occurrence of each legion is counted. Finally, 89 probabilistic ROI volumes are generated. This paper presents a probabilistic anatomical map for localizing the functional and structural analysis of Korean normal brain. In the future, we'll develop the group specific probabilistic anatomical maps of OCD and schizophrenia disease.

• Korean Journal of Acupuncture
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• v.21 no.3
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• pp.21-38
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• 2004

Objectives : Moxibustion has been become very useful tool to prevent and treat various diseases with acupuncture in oriental medicine. Expecially, moxibustion combining the heat stimulation and chemical stimulation of Artemisiae Argyi has a non-invasive characteristics comparing to the other therapeutic tools. However, because the moxibustion makes the patient's skin be burn by the combustible feature of moxibustion, most of people have been scared of being scald. Methods : In this study, we have developed new non-combustible moxibustion tools in collaboration with company (Hana Medical, co. and ICURE, co.) and tested the efficacy through effects of moxibustion of Cheon-chu $(ST_{25})$ on the abdominal thermography of health subject. The non-combustible moxibustion has main characteristics of controlled heating to inhibit being scald and heat stimulation lasting over 1 hrs. Also, to induce the chemical stimulation, the bottom contacting with skin was coated by the extract of artemisiae argyi. The volunteers who participating in this study had taken rest for 20 - 30 mins in room temperature $(23-25^{\circ}C)$ before the examination and informed them what to prohibit smoking, drinking and administration of drug for the previous day The thermography of abdomen including a below part of the chest was taken using Infra-Red Imaging System (IR 2000, MEDI-CORE Co., Korea) by time interval of 15 minutes. Results : The results showed that moxibustion of Cheon-chu $(ST_{25})$ had more potencies of changes on all the ROIs of abdominal thermography than those of control group. Also, it was observed that the quantities of thermal changes following moxibustion of Cheon-chu $(ST_{25})$ been increased significantly comparing that of control group at all the ROIs (region of interest). Observed the thermography classified by ROI, however, moxibustion of Cheon-chu $(ST_{25})$ could modulate ipsilateral specific areas concerning to the abdominal pathway of Stomach Meridian. Conclusion : These results suggest that new non-combustible moxibusion has some similarity as like as the conventional moxibustion and moxibustion of Cheon-chu $(ST_{25})$ may modulate thermal changes of abdominal areas.

• Journal of Oral Medicine and Pain
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• v.36 no.3
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• pp.177-185
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• 2011

Aims: The purpose of this study was to evaluate the relationship between temporomandibular joint pain and the relative signal intensity (RSI) of retrodiscal tissue on T1-, and T2-weighted MRI images. Materials and Methods: This study was based on 122 TMJs of 61 patients who complain of TMJ pain in only one side but were revealed to have disc displacement in both TMJs according to MRI findings. The signal intensities of regions of interest (ROIs) in retrodiscal tissues were measured using T1-, and T2-weighted MRI images. The RSIs of retrodiscal tissues were referenced to the signal intensities of the ROIs of brain gray matter. The relationships between the RSI of retrodiscal tissue and joint pain, joint effusion, condylar degenerative change, and degree of disc displacement were examined. In addition, the relationships between joint pain and joint effusion, condylar degenerative change, and degree of disc displacement were examined. Results: On T1-weighted MR images, the painful TMJs showed significantly higher retrodiscal tissue RSI than non-painful TMJs. In addition, there is an association between joint pain and the degree of disc displacement. However, on T2-weighted MR images, the RSIs of retrodiscal tissues didn't show any significant differences with regard to joint pain, joint effusion, condylar degenerative change, and degree of disc displacement. Conclusions: The signal intensity of retrodiscal tissue can be used as a diagnostic marker for painful TMJ. However, the overall results suggest the signal intensity of retrodiscal tissue has a limited diagnostic significance in determining the pathologic status of TMJ.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.16 no.4
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• pp.246-253
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• 2016

Infrared (IR) imaging has been researched for various applications such as surveillance. IR radiation has the capability to detect thermal characteristics of objects under low-light conditions. However, automatic segmentation for finding the object of interest would be challenging since the IR detector often provides the low spatial and contrast resolution image without color and texture information. Another hindrance is that the image can be degraded by noise and clutters. This paper proposes multi-level segmentation for extracting regions of interest (ROIs) and objects of interest (OOIs) in the IR scene. Each level of the multi-level segmentation is composed of a k-means clustering algorithm, an expectation-maximization (EM) algorithm, and a decision process. The k-means clustering initializes the parameters of the Gaussian mixture model (GMM), and the EM algorithm estimates those parameters iteratively. During the multi-level segmentation, the area extracted at one level becomes the input to the next level segmentation. Thus, the segmentation is consecutively performed narrowing the area to be processed. The foreground objects are individually extracted from the final ROI windows. In the experiments, the effectiveness of the proposed method is demonstrated using several IR images, in which human subjects are captured at a long distance. The average probability of error is shown to be lower than that obtained from other conventional methods such as Gonzalez, Otsu, k-means, and EM methods.

• The Journal of the Korea Contents Association
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• v.4 no.4
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• pp.79-87
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• 2004

In this paper, we propose a probability map based genetic algorithm to detect lips from portrait image. The existing genetic algorithm used to get an optimal solution is modified in order to get multiple optimal solutions for lips detection. Each individual consists of two chromosomes to represent coordinates x, y in space. Also the algorithm introduce a preserving zone in the population, a modified uniform crossover, a selection without individual duplication. Using probability map of H, 5 components, the proposed algorithm has adaptability in the segmentation of objects with similar colors. In experiments, we analyzed relationships of primary parameters and found that the algorithm can apply to the detection of other ROIs easily

• Proceedings of the Korean Society of Medical Physics Conference
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• 2002.09a
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• pp.429-431
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• 2002

Metabolic analysis of biological tissues, the interventional radiology in MRT (Magnetic Resonance Treatment) and for clinical diagnoses, representation of 4-Dimensional (4D) structural information (x,y,z,t) of biological tissues is required. This paper discusses image representation techniques for those 4D MR Images. We have proposed an image reconstruction method for ultra-fast 3D MRI. It is based on image interpolation and prediction of un-acquired pictorial data in both of the real and the k-space (the acquisition domain in MRI). A 4D MR image is reconstructed from only two 3D MR images and acquired a few echo signals that are optimized by prediction of the tissue motion. This prediction can be done by the phase of acquired echo signal is proportioned to the tissue motion. On the other hand, reconstructed 4D MR images are represented as a 3D-movie by using computer graphics techniques. Rendered tissue surfaces and/or ROIs are displayed on a CRT monitor. It is represented in an arbitrary plane and/or rendered surface with their motion. As examples of the proposed representation techniques, the finger and the lung motion of healthy volunteers are demonstrated.

• The Korean Journal of Nuclear Medicine Technology
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• v.13 no.1
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• pp.82-85
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• 2009

Purpose: The purpose of this study was to evaluate the effect of extended CT field of view (FOV) on PET/CT of Standardized uptake value (SUV) when imaging extends beyond the CT FOV. Materials and Methods: CT images were reconstructed at different FOV sizes (500 and 700 mm). Two sets of CT images were reconstructed from the CT projection data by using two FOV sizes. Twenty patients were used in this study. PET images were reconstructed using attenuation maps with 500 mm CT FOV and 700 mm extended CT FOV images. Region of interests (ROIs) drawn on the PET images. In addition, twenty patients' PET images reconstructed by 500 mm CT FOV and 700 mm extended CT FOV were compared with $SUV_{max}$. Results: When using attenuation maps with 700 mm extended CT FOV, the $SUV_{max}$ analysis of liver (p=0.000), lung (p=0.007), mediastinum (p=0.001) were statistically significant. Conclusions: 700 mm extended CT FOV helps to recover the true activity distribution in the PET emission data. In addition, 700 mm extended CT FOV has affected SUV measurement of liver, lung, mediastinum.