• Journal of Digital Convergence
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• v.11 no.10
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• pp.577-584
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• 2013

IGRT(Image Guided Radiation Therapy) in radiation therapy is a very useful technique in order to increase setup of patient and position reproducibility. Tomotherapy can increase accuracy of setup to take IGRT by MVCT, but it be for verified accuracy of Image guided, and MVCT occurs the exposure of patient. Through this study, IGRT accuracy of Tomotherapy is very accurate within 1.0mm. When MVCT using Tomotherapy phantom for QA, QC be taken, exposure dose is Fine(2mm Slice thickness) 3cGy, Normal(4mm Slice thickness) 1.5cGy, Corse(6mmSlice thickness) 1.0cGy. Measurement value of spatial resolution using AAPM CT performance phantom did't cause a big difference. As a result, ability of IGRT in Tomotherapy is very accurate. While obtaining image for IGRT, we should minimize expose range because patient's be exposed to radiation. We should make an effort to do accurate radiation therapy to minimize exposure of patient by selecting the appropriate thickness of MVCT depending on patient's body and treat area.

• Journal of the Korea Society of Computer and Information
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• v.29 no.7
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• pp.41-51
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• 2024

In this paper, we explore the enhancement of target detection accuracy in the guided weapon using deep learning object detection on infrared (IR) images. Due to the characteristics of IR images being influenced by factors such as time and temperature, it's crucial to ensure a consistent representation of object features in various environments when training the model. A simple way to address this is by emphasizing the features of target objects and reducing noise within the infrared images through appropriate pre-processing techniques. However, in previous studies, there has not been sufficient discussion on pre-processing methods in learning deep learning models based on infrared images. In this paper, we aim to investigate the impact of image pre-processing techniques on infrared image-based training for object detection. To achieve this, we analyze the pre-processing results on infrared images that utilized global or local information from the video and the image. In addition, in order to confirm the impact of images converted by each pre-processing technique on object detector training, we learn the YOLOX target detector for images processed by various pre-processing methods and analyze them. In particular, the results of the experiments using the CLAHE (Contrast Limited Adaptive Histogram Equalization) shows the highest detection accuracy with a mean average precision (mAP) of 81.9%.

• Journal of the Korean Society for Nondestructive Testing
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• v.29 no.4
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• pp.338-343
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• 2009

Tomography is the imaging method of cross sectional area using multi beam signals and is mainly applied to the medical diagnosis to acquire the image of the inside human body. This method is pretty meaningful in nondestructive evaluation field since the imaging of the inspection region can enhance the comprehension of the inspector. Recently, much attention has been paid to the guided wave for the diagnosis of platelike structures. So, in this work, a study on the imaging of the damage location in a plate was carried out on the basis of computer aided analysis of guided waves and tomographic imaging. To this end, boundary element method was employed to analyze the effect of the damage in plate on the propagation of the guided waves and the analytic results were applied to the tomographic imaging method to identify the damage location. Consequently, it was shown that the number of sensors heavily affect the inspection performance of the damage location.

• Korean Journal of Radiology
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• v.22 no.7
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• pp.1203-1212
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• 2021

Objective: To investigate the diagnostic accuracy and complications of cone-beam CT-guided percutaneous transthoracic needle biopsy (PTNB) of juxtaphrenic lesions and identify the risk factors for diagnostic failure and complications. Materials and Methods: In total, 336 PTNB procedures for lung lesions (mean size ± standard deviation [SD], 4.3 ± 2.3 cm) abutting the diaphragm in 326 patients (189 male and 137 female; mean age ± SD, 65.2 ± 11.4 years) performed between January 2010 and December 2014 were included. The accuracy, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of the PTNB procedures for the diagnosis of malignancy were measured based on the intention-to-diagnose principle. The risk factors for diagnostic failures and complications were evaluated using logistic regression analysis. Results: The accuracy, sensitivity, specificity, PPV, and NPV were 92.7% (293/316), 91.3% (219/240), 91.4% (74/81), 96.9% (219/226), and 77.9% (74/95), respectively. There were 23 diagnostic failures (7.3%), and lesion sizes ≤ 2 cm (p = 0.045) were the only significant risk factors for diagnostic failure. Complications occurred in 98 cases (29.2%), including 89 cases of pneumothorax (26.5%) and 7 cases of hemoptysis (2.1%). The multivariable analysis showed that old age (> 65 years) (p = 0.002), lesion size of ≤ 2 cm (p = 0.003), emphysema (p = 0.006), and distance from the pleura to the target lesion (> 2 cm) (p = 0.010) were significant risk factors for complications. Conclusion: The diagnostic accuracy of cone-beam CT-guided PTNB of juxtaphrenic lesions for malignancy was fairly high, and the target lesion size was the only significant predictor of diagnostic failure. Complications of cone-beam CT-guided PTNB of juxtaphrenic lesions occurred at a reasonable rate.

• Radiation Oncology Journal
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• v.35 no.3
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• pp.274-280
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• 2017

Purpose: To see the gross tumor volume (GTV) dependency according to the phase selection and reconstruction methods, we measured and analyzed the changes of tumor volume and motion at each phase in 20 cases with lung cancer patients who underwent image-guided radiotherapy. Materials and Methods: We retrospectively analyzed four-dimensional computed tomography (4D-CT) images in 20 cases of 19 patients who underwent image-guided radiotherapy. The 4D-CT images were reconstructed by the maximum intensity projection (MIP) and the minimum intensity projection (Min-IP) method after sorting phase as 40%-60%, 30%-70%, and 0%-90%. We analyzed the relationship between the range of motion and the change of GTV according to the reconstruction method. Results: The motion ranges of GTVs are statistically significant only for the tumor motion in craniocaudal direction. The discrepancies of GTV volume and motion between MIP and Min-IP increased rapidly as the wider ranges of duty cycles are selected. Conclusion: As narrow as possible duty cycle such as 40%-60% and MIP reconstruction was suitable for lung cancer if the respiration was stable. Selecting the reconstruction methods and duty cycle is important for small size and for large motion range tumors.

• Journal of Korean Neurosurgical Society
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• v.46 no.6
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• pp.577-580
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• 2009

A 47-year-old man presented with a subarachnoid hemorrhage (SAH) and right cerebellar hematoma was referred for evaluation. Cerebral angiography revealed a distal anterior inferior cerebellar artery (AICA) aneurysm associated with an arteriovenous malformation (AVM). Successful obliteration and complete removal of the aneurysm and AVM were obtained using transcortical approach under the guidance of neuronavigation system. The association of a peripheral AICA aneurysm and a cerebellar AVM by the same artery is unique. The reported cases of conventional surgery for this disease complex are not common and their results are variable. Less invasive surgery using image-guided neuronavigation system would be helpful and feasible for a peripheral aneurysm combining an AVM of the posterior fossa in selective cases

• Nuclear Engineering and Technology
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• v.46 no.2
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• pp.255-262
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• 2014

During image-guided radiation therapy, the patient is exposed to unwanted radiation from imaging devices built into the medical LINAC. In the present study, the effective dose delivered to a patient from a cone beam computed tomography (CBCT) machine was measured. Absorbed doses in specific organs listed in ICRP Publication 103 were measured with glass dosimeters calibrated with kilovolt (kV) X-rays using a whole body physical phantom for typical radiotherapy sites, including the head and neck, chest, and pelvis. The effective dose per scan for the head and neck, chest, and pelvis were $3.37{\pm}0.29$, $7.36{\pm}0.33$, and $4.09{\pm}0.29$ mSv, respectively. The results highlight the importance of the compensation of treatment dose by managing imaging dose.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.49 no.1
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• pp.13-20
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• 2021

In this paper, a new algorithm is proposed to estimate the damage size by combining the reflected area with the reflected position and extracting contours in proportion to the maximum value of pixels from the visible image. The cumulative summation feature vector algorithm is used to obtain the area of the reflected signal. To get the position of the reflected signal, the signal correlation algorithm is used to decompose the reflected signal from the damage. The proposed algorithm is tested and validated for composite panels. Repetitive experiments are performed and it is confirm that the proposed algorithm is reproducible. Further, it is verified that the damage size can be estimated appropriately by the proposed algorithm.

• Korean Journal of Radiology
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• v.24 no.8
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• pp.719-728
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• 2023

Radiofrequency ablation (RFA) has been widely used to manage hepatocellular carcinomas (HCCs) equal to or smaller than 3 cm. No-touch RFA has gained attention and has recently been implemented in local ablation therapy for HCCs, despite its technical complexity, as it provides improved local tumor control compared to conventional tumor-puncturing RFA. This article presents the practice guidelines for performing no-touch RFA for HCCs, which have been endorsed by the Korean Society of Image-Guided Tumor Ablation (KSITA). The guidelines are primarily designed to assist interventional oncologists and address the limitations of conventional tumor-puncturing RFA with describing the fundamental principles, various energy delivery methods, and clinical outcomes of no-touch RFA. The clinical outcomes include technical feasibility, local tumor progression rates, survival outcomes, and potential complications.

• Journal of Korean Neurosurgical Society
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• v.50 no.5
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• pp.446-452
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• 2011

Objective : We retrospectively investigated the long-term results of percutaneous radiofrequency thermocoagulation (RFT) using fluoroscopic image-guidance for treatment of trigeminal neuralgia. Methods : A total of 38 patients diagnosed and treated with RFT as an idiopathic trigeminal neuralgia were investigated. To minimize the risks related to conventional technique based on cutaneous landmarks, and to eliminate the need to frequent reposition of cannula, we adopted a technique of image-guided fluoroscopic cannulation of the foramen ovale. To minimize sensory complication following thermal lesion, our target response was a generation of a lesion with mild to moderate hypalgesia rather than dense hypalgesia. Results : The immediate pain-relief was achieved in all patients underwent RFT. With mean duration of follow-up of 38.2 months (range,12-72), 11 (28.9%) experienced recurrence of pain. The mean timing of recurrence was 26.1 months (range,12-46). A 42.7% recurrence rate was estimated by Kaplan-Meier analysis for the 38 patients at 46 months; 20.2% within 2 years, 29.1% within 3 years. In the long-term, 27 patients (71%) and 6 patients (15.8%) showed Barrow Neurological Institute (BNI) score I and BNI score II responses. Three (7.9%) patients was assessed as BNI score III, 2 patients (5.3%) showed BNI score IV response. As a complication, troublesome dysesthesia occurred in 3 of 38 patients (7.9%), however, there was no permanent cranial nerve palsy or morbidity. Conclusion : These results indicates that RFT under fluoroscopic image-guided cannulation of foramen ovale is a safe, effective, and reliable means of treating trigeminal neuralgia.