Mingi Kim

A study of a method for distribution analysis of skin color

Background/aims: The objective and quantitative assessment of the skin is important in medical and cosmeceutical research. Assessment of color is an important element for analyzing the surface of the skin, which is usually determined subjectively by a doctor or using color analysis devices. These devices, however, cannot provide correct color information because color is construed from the mean value of the observation region, and analysis of color distribution is impossible. The purpose of this paper is to develop an objective analysis method to permit skin color measurement of each pixel unit of an image and analyze the distribution of skin surface color.

Effect of pedunculagin investigated by non‐invasive evaluation on atopic‐like dermatitis in NC/Nga mice

Background/purpose: Atopic dermatitis (AD) is a chronic relapsing inflammatory skin disorder that is becoming increasingly prevalent. Experimental animal models have been an indispensable tool for studying its pathological mechanisms and for in vivo testing of novel therapeutic approaches. AD‐like lesions can be induced experimentally in NC/Nga mice. Pedunculagin, an ellagitannin purified from the Manchurian alder, Alnus hirsuta var. microphylla, Betulaceae, is a novel immunomodulator. To evaluate the effect of pedunculagin for AD‐like lesions in NC/Nga mice, using clinical and non‐invasive methods.

Improved quantitative evaluation of atopic dermatitis by camera calibration and rectification of a stereo image.

Background/Purpose: The aim of this study was to establish a scientific assessment method to evaluate the severity of atopic dermatitis (AD) by calibrating part of a previously described stereo‐image optical topometer (SOT).

Resolving the Initial Contour Problem of GVF Snake in the Sequential Images

GVF algorithm has been studied actively and it will be able to apply to quite many applications. This paper presents GVF algorithm for the segmentation of a sequence of images. Traditional GVF algorithm can extract contour of object in an image. However, in the video sequence images or CT images traditional GVF algorithm had some problems. We can treat these problems under motion tracking using motion estimation using mean square error (MSE). Initial point problem is very important in GVF algorithm. We applied extracted initial point of first image to the second image. In other word, previous initial contour can be used to the next initial contour.

Segmentation of the left ventricle in myocardial perfusion SPECT using variational level set formulation

Myocardial scintigraphy is an imaging modality which provides functional information. We used myocardium SPECT images performed at stress and rest with Tc-99m MIBI. The myocardial perfusion is estimated by comparing images at two different instant rest and stress and it is indicated when ischemia is from the normal case suspected. The diagnosis is obtained by comparing the topology of myocardium blood flow at these different instants. Shape instabilities have been an important problem, particularly in 3D. Since then, different approaches to the solution of this problem have been developed, we proposed an variational level set based on Mumford-Shah segmentation techniques and the variational level set method. Its strategy is first searching the object in the dataset. For tracing its exact contour, we can detect objects whose boundaries are not necessarily defined by gradient or with very smooth boundaries, for which the classical active contour models are not applicable. This segmentation method was fast and robust on noisy, low-resolution data. Rendered surface of the endocardium and epicardium wall at stress and rest the contours of heart are very well detected and preserved. The method could be used to extract quantitative functional parameters.

THE CUT-OFF VALUES FOR AUTO-DETECTION OF LUNG CANCER IN CHEST RADIOGRAPHY: AN EXAMPLE USING AN UNSUPERVISED METHOD

Aim: For automatic recognition of lung cancer, a previous step to detect nodules automatically is needed. The aim is to propose a feature descriptor to detect the various types of nodules automatically and evaluate its performance. Materials and Methods: For experimental imaging, control group sub-image (n = 50), benign group sub-image (n = 32), malignant group sub-image (n = 38) were used, and feature of image was extracted through TIA and PCA. An excellent method was selected by using the following ROC curve analysis. Results: The experiment showed the result of the best area under the ROC curve (AUC) was shown when using TIA feature descriptor. The value at this time was 95.9 in the control group-benign group and 95.1 in the control group-malignant group. When using TIA feature descriptor, the cut-off value results were shown to be 116.4 in the control group-benign group (sensitivity: 88.9%, specificity: 90.3%), and 149.1 in the control group-malignant group (Sensitivity: 86.4%, Specificity: 92.1%). Conclusion: The proposed method can be applied to chest radiography for the automatic detection of nodules for the automatic diagnosis of lung cancer, and excellent results can be obtained.

An extended Kalman filter for mouse tracking

AbstractAnimal tracking is an important tool for observing behavior, which is useful in various research areas. Animal specimens can be tracked using dynamic models and observation models that require several types of data. Tracking mouse has several barriers due to the physical characteristics of the mouse, their unpredictable movement, and cluttered environments. Therefore, we propose a reliable method that uses a detection stage and a tracking stage to successfully track mouse. The detection stage detects the surface area of the mouse skin, and the tracking stage implements an extended Kalman filter to estimate the state variables of a nonlinear model. The changes in the overall shape of the mouse are tracked using an oval-shaped tracking model to estimate the parameters for the ellipse. An experiment is conducted to demonstrate the performance of the proposed tracking algorithm using six video images showing various types of movement, and the ground truth values for synthetic images are compared to the values generated by the tracking algorithm. A conventional manual tracking method is also applied to compare across eight experimenters. Furthermore, the effectiveness of the proposed tracking method is also demonstrated by applying the tracking algorithm with actual images of mouse. Graphical abstract

Multimodal evaluation of xenograft tumors in mice with an in-vivo stereo imaging system and small-animal PET/CT

In small-animal studies, calipers are the standard method used for measurement of external tumor size. However, as tumors are not usually prolate spheroids, this may lead to inaccuracies in the data. Also, correlations vary according to the kind and size of tumors. Tumors were generated by transplanting B16 mouse melanoma cells into the back of Balb/c nude mice. True volumes were measured by calipers, an in-vivo stereo imaging system, and as a standard uptake value (SUV) by 18F-fluorodeoxyglucose ([18F]FDG)-PET. Correlations between measurements were analyzed. Correlation with the true volume was higher for measurements using the in-vivo stereo imaging system (r=0.876) than with calipers (r=0.744). Measurement of melanoma volume has a larger measuring error when performed using a caliper compared with measurements performed by stereo imaging when the volume of the melanoma is small. Correlation of the volume and PET-SUV by a caliper is low as the size of the melanoma increases. This same relationship exists with the comparison of stereo imaging and PET-SUV. The correlation between the SUV of [18F]FDG-PET and tumor volume with the melanoma is expected to be important in related future studies.

To detect the posture of an endoscope from a sequence of endoscopic images

This paper presents a method of detecting camera posture from endoscopic images. In epipolar geometry, the fundamental matrix provides some geometric information including translation and rotation of cameras. Although it is well known that DLT(Direct Linear Transform) algorithm can be an efficient method to calculate the matrix, it depends upon performance of matching points. The Levenberg-Marquardt algorithm which is robust for estimation with Gaussian noise can be a good method for this reason. In this paper, the distance between matched points and epipolar lines is defined and the fundamental matrix is accurately computed by the Levenberg- Marquardt algorithm using DLT algorithm to find the initial value. Also, good translation and rotation information can be obtained by decomposing the fundamental matrix. Experimental results show the improvement of the result of the fundamental matrix that result in improvement of the camera posture also. The detection of the pose of endoscope is important for compute added diagnosis in medical applications.

Implementation of Enhanced Image from Backscatter X-ray System

Considerable attention has been focused on digital X-ray systems with transmission. However, only a few attempts have been made using X-ray backscatter system. It has difficulty that we have to reconstruct image from a little data in the image processing. Especially, it is necessary that the method correct error of detector effectively. That is the most important thing in the acquisition of X-ray data. In this paper, it is that propose some data processing methods that correct error of detector, and we can recognize that the image reconstruction from a little data is effective