• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.11 no.3
• /
• pp.880-890
• /
• 2010

The intrasvascular ultrasound (IVUS) imaging technique is used to diagnose cerebrovascular diseases such as stroke. Recently, elasticity imaging methods have been investigated to diagnose blood clots attached to blood vessel intima. However, the IVUS imaging technique is an invasive method that requires a transducer to be inserted into blood vessel. In this paper, strain images are obtained of blood clots attached to blood vessel intima with data acquired from outside the blood vessel using a linear array transducer. In order to measure the displacement of blood vessel accurately, experimental data are acquired by steering ultrasound beams so that they can intersect the blood vessel wall at right angles. The acquired rf data are demodulated to the baseband. The resulting complex baseband signals are then processed by an autocorrelation algorithm to compute the blood vessel movement and thereby produce strain image. This proposed method is verified by experiments on a plastic blood vessel mimicking phantom. The efficacy of the proposed method was verified using a home-made blood vessel mimicking phantom. The blood vessel mimicking phantom was constructed by making a 6 mm diameter hollow cylinder inside it to simulate a blood vessel and adhering 2 mm thick soft plaque to the inner wall of the hollow cylinder. The RF data were acquired using a clinical ultrasound scanner (Accuvix XQ, Medison, Seoul. Korea) with a 7.5 MHz linear array transducer by steering ultrasound beams in steps of $1^{\circ}$ from $-40^{\circ}$ to $40^{\circ}$ for a total of 81 angles. Experimental results show that the plaque region near the blood vessel wall is softer than background tissue. Although the imaging region is restricted due to the limited range of angles for which scan lines are perpendicular to the wall, the feasibility of strain imaging is demonstrated.

• Journal of the Institute of Electronics Engineers of Korea SD
• /
• v.38 no.5
• /
• pp.338-346
• /
• 2001

An infrared imaging method in which direct measurement of energy gap variations can be achieved by digital image processing is proposed. This method allows economic and easy evaluation of the temperature coefficients of a semiconductor energy gap. The key components of the method are a polychromator, a computer equipped with a frame grabber and a variable temperature cryostat. Tentative experimentation conducted on LEC grown semi-insulating GaAs has resulted in a fairly good agreement with the theoretical model. This proposed method could be applicable for most compound semiconductors.

• Proceedings of the KSRS Conference
• /
• 2005.10a
• /
• pp.197-200
• /
• 2005

Super resolution image reconstruction method refers to image processing algorithms that produce a high resolution(HR) image from observed several low resolution(LR) images of the same scene. This method is proved to be useful in many practical cases where multiple frames of the same scene can be obtained, such as satellite imaging, video surveillance, video enhancement and restoration, digital mosaicking, and medical imaging. In this paper we applied super resolution reconstruction method in spatial domain to video sequences. Test images are adjacently sampled images from continuous video sequences and overlapped for high rate. We constructed the observation model between the HR images and LR images applied by the Maximum A Posteriori(MAP) reconstruction method that is one of the major methods in the super resolution grid construction. Based on this method, we reconstructed high resolution images from low resolution images and compared the results with those from other known interpolation methods.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.10 no.10
• /
• pp.1848-1853
• /
• 2006

In this paper, we propose a method to reconstruct resolution-improved 3D images computationally based on lenslet array model in integral imaging technique and analyze its performance. While conventional view-point reconstruction method has low resolution based on pinhole array model, the proposed method can obtain resolution-improved 3D images because of extracting multiple pixels from elemental images by use of lenslet way model. To show the usefulness of proposed method, we perform computational experiments and present its results.

• Journal of Biomedical Engineering Research
• /
• v.26 no.1
• /
• pp.31-35
• /
• 2005

A novel synthetic aperture method for real-time three-way dynamic focusing is proposed, which provides lateral beam patterns represented as the product of Fourier transforms of transmit subaperture, receive subaperture, and a synthetic window function. In the proposed method, all array elements are fired individually and for each firing echo signals are recorded from all elements of a receive subaperture moving along an array with the transmit element. The three-way dynamic focusing is then achieved by employing a synthetic aperture algorithm for two-way dynamic focusing and a synthetic focusing method for transmit dynamic focusing. Both theoretical analysis and computer simulation results show that the proposed method produces ultrasound beams with improved lateral resolution at all depths compared to the conventional phased array imaging and synthetic aperture focusing methods.

• Asian Pacific Journal of Cancer Prevention
• /
• v.14 no.11
• /
• pp.6331-6335
• /
• 2013

Objective:To evaluate the performance of combined quantitative analysis of thyroid blood flow and static imaging data in the differential diagnosis of thyroid nodules. Method: Thyroid blood flow and static imaging were performed in 165 patients with thyroid nodules. Patients were divided into a benign thyroid nodule group (BTN, n=135) and a malignant thyroid nodule group (MTN, n=30) based on the results of post-surgical pathologic examination. Carotid artery thyroid transit times (CTTT), perfusion ratio of thyroid nodule blood/thyroid blood (TNB/TB), and perfusion ratio of thyroid nodule blood/carotid artery blood (TNB/CAB) were measured using thyroid blood flow imaging. The ratios between thyroid nodule and ipsilateral submandibular gland (TN/SG) and thyroid nodule and normal thyroid tissue (TN/T) were measured from thyroid static imaging. The differences between the BTN and MTN groups were compared. Results: 1) CTTT was markedly lower in the MTN group than the BTN group, the difference being statistically significant. 2) TNB/TB and TNB/CAB were both significantly higher in MTN than BTN groups. 3) TN/T was significantly lower in MTN group than BTN group. 4) TN/SG was lower in MTN group than BTN group, but the difference was not statistically significant. 5) Using the combination of CTTT and TN/T, the sensitivity, specificity and accuracy were 93.1%, 95.3% and 94.9% respectively for the diagnosis of MTN. Using the combination of CTTT, TNB/TB and TN/T, the sensitivity, specificity and accuracy changed to 89.7%, 100%, and 98.1% respectively. 6) Correlation analysis demonstrated a significant correlation between TN/T and TNB/TB (r=-0.384, P=0.036) and TNB/CAB (r=-0.466, P=0.009) in the MTN group. Conclusion: The combination of quantitative markers from thyroid blood flow and thyroid static imaging had high specificity and accuracy in differential diagnosis of benign and malignant thyroid nodules, thus providing an important imaging diagnostic approach.

• Biomedical Science Letters
• /
• v.21 no.1
• /
• pp.23-31
• /
• 2015

Recently, specific antibodies have been used extensively to diagnose and treat various diseases. It is essential to assess the efficacy and specificity of antibodies, especially the in vivo environment. Anti-HER-2/neu mAb was evaluated as a possible transporting agent for radioimmunotherapy. The monoclonal antibody was successfully radio-labeled with $^{131}I$. In vitro binding assays were performed to confirm its targeting ability using another radio-iodine, $^{125}I$. Binding percentage of $^{125}I$ labeled anti-HER-2/neu mAb in HER-2/neu expressing CT-26 cells was found to be 4.5%, whereas the binding percentage of $^{125}I$ labeled anti-HER-2/neu mAb in wild-type CT-26 was only 0.45%. In vivo images were obtained and analyzed through $\gamma$-camera and an optical fluorescent modality, IVIS-200. $\gamma$-camera images showed that $^{131}I$ labeled anti-HER-2/neu mAb accumulated in HER-2/neu CT-26 tumors. Optical imaging based on near infrared fluorescence labeled anti-HER-2/neu mAb showed higher fluorescence intensities in HER-2/neu CT-26 tumors than in wild-type CT-26 tumors. Anti-HER-2/neu mAb was found to specifically bind to its receptor expressing tumor. Our study demonstrates that in vivo imaging technique is a useful method for the evaluation of an antibody's therapeutic and diagnostic potentials.

• Investigative Magnetic Resonance Imaging
• /
• v.25 no.1
• /
• pp.1-9
• /
• 2021

The aim of this study was to provide a new assessment of rotator cuff muscle activity. Eight male subjects (24.7 ± 3.2 years old,171.2 ± 9.8 cm tall, and weighing 63.8 ± 11.9 kg) performed the study exercises. The subjects performed 10 sets of the exercise while fixing the elbow at 90 degrees flexure and lying supine on a bed. One exercise set consisted of the subject performing external shoulder rotation 50 times using training equipment. Two imaging protocols were employed: (a) true fast imaging with steady precession (TrueFISP) at an acquisition time of 12 seconds and (b) multi-shot spin-echo echo-planar imaging (MSSE-EPI) at an acquisition time of 30 seconds for one echo. The main method of assessing rotator cuff muscle activity was functional T2 mapping using ultrafast imaging (fast-acquired muscle functional MRI [fast-mfMRI]). Fast-mfMRI enabled real-time imaging for the identification and evaluation of the degree of muscle activity induced by the exercise. Regions of interest were set at several places in the musculus subscapularis (sub), musculus supraspinatus (sup), musculus teres minor (ter), and deltoid muscle (del). We used the MR signal of the images and transverse relaxation time (T2) for comparison. Most of the TrueFISP signal was not changed by exercise and there was no significant difference from the resting values. Only the T2 in the musculus teres minor was increased after one set and the change were seen on the T2 images. Additionally, except for those after one and two sets, the changes in T2 were significant compared to those at rest (P < 0.01). We also demonstrated identify and visualize the extent to which muscles involved in muscle activity by exercise. In addition, we showed that muscle activity in a region such as a shoulder, which is susceptible to B0 inhomogeneity, could be easily detected using this technique.

• Journal of Biomedical Engineering Research
• /
• v.42 no.5
• /
• pp.241-249
• /
• 2021

Recently, artificial intelligence for diagnosis system of obstetric diseases have been actively studied. Artificial intelligence diagnostic assist systems, which support medical diagnosis benefits of efficiency and accuracy, may experience problems of poor learning accuracy and reliability when inappropriate images are the model's input data. For this reason, before learning, We proposed an algorithm to exclude unread cervical imaging. 2,000 images of read cervical imaging and 257 images of unread cervical imaging were used for this study. Experiments were conducted based on the statistical method Radiomics to extract feature values of the entire images for classification of unread images from the entire images and to obtain a range of read threshold values. The degree to which brightness, blur, and cervical regions were photographed adequately in the image was determined as classification indicators. We compared the classification performance by learning read cervical imaging classified by the algorithm proposed in this paper and unread cervical imaging for deep learning classification model. We evaluate the classification accuracy for unread Cervical imaging of the algorithm by comparing the performance. Images for the algorithm showed higher accuracy of 91.6% on average. It is expected that the algorithm proposed in this paper will improve reliability by effectively excluding unread cervical imaging and ultimately reducing errors in artificial intelligence diagnosis.

• Imaging Science in Dentistry
• /
• v.53 no.3
• /
• pp.209-216
• /
• 2023

Purpose: This study was conducted to compare dental plaque scores obtained through clinical examinations and various imaging techniques, as well as to assess the effectiveness of herbal and conventional toothpastes for plaque removal. Materials and Methods: Thirty volunteers were divided into 3 groups. Each group was given a different toothpaste (from 2 herbal toothpastes and a conventional toothpaste) with which to brush their teeth for 21 days. Both initially and after brushing, dental plaque samples were collected, and plaque on the buccal surfaces of anterior teeth was scored using several imaging systems after staining with a disclosing agent. Specifically, digital dental photography, intraoral digital scanning, and FluoreCam imaging were employed to capture intraoral images. The Turesky Modified Quigley-Hein Plaque Index was used for clinical examination and image analysis. Quantitative polymerase chain reaction analyses and correlational assessments between clinical examination and imaging scores were conducted before and after toothpaste use. The Shapiro-Wilk test and Pearson correlations were utilized. Results: The lowest mean value was observed in the clinical examination without staining, while the highest was obtained using the FluoreCam method. No significant change was found in the level of any microorganism assessed following toothpaste use (P<0.05), with the exception of a decrease in S. mutans levels after using conventional toothpaste (P<0.05). Conclusion: Herbal toothpaste demonstrated plaque-removal effectiveness comparable to that of conventional toothpaste. The use of imaging methods for measuring plaque index has been suggested as a means to educate patients about plaque control and promote ongoing oral care.