• Journal of Trauma and Injury
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• v.35 no.1
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• pp.12-18
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• 2022

Purpose: Pedicle screw fixation provides 3-column stabilization, multidimensional control, and a higher rate of interbody fusion. Although computed tomography (CT) is recommended for the postoperative assessment of pedicle screw fixation, its use is limited due to the radiation exposure dose. The purpose of this preliminary retrospective study was to assess the clinical usefulness of low-dose mobile cone-beam CT (CBCT) for the postoperative evaluation of pedicle screw fixation. Methods: The author retrospectively reviewed postoperative mobile CBCT images of 15 patients who underwent posterior pedicle screw fixation for spinal disease from November 2019 to April 2020. Pedicle screw placement was assessed for breaches of the bony structures. The breaches were graded based on the Heary classification. Results: The patients included 11 men and four women, and their mean age was 66±12 years. Of the 122 pedicle screws, 34 (27.9%) were inserted in the thoracic segment (from T7 to T12), 82 (67.2%) in the lumbar segment (from L1 to L5), and six (4.9%) in the first sacral segment. Although there were metal-related artifacts, the image of the screw position (according to Heary classification) after surgery could be assessed using mobile CBCT at all levels (T7-S1). Conclusions: Mobile CBCT was accurate in determining the location and integrity of the pedicle screw and identifying the surrounding bony structures. In the postoperative setting, mobile CBCT can be used as a primary modality for assessing the accuracy of pedicle screw fixation and detecting postoperative complications.

• Korean Journal of Heritage: History & Science
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• v.51 no.3
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• pp.32-53
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• 2018

The $Sh{\bar{o}}s{\bar{o}}-in$(正倉院) is the detached storage building for Japanese treasures that belongs to $T{\bar{o}}dai-ji$ in Nara, Japan. The reason why $Sh{\bar{o}}s{\bar{o}}-in$ collections are drawing attention is that Japanese artifacts, sculptures, paintings, and other objects that were introduced through the Silk Road, such as Sasanian Persia and India, and those that were introduced from the Unified Silla and Tang China. In addition, hundreds of well-preserved documents of $Sh{\bar{o}}s{\bar{o}}-in$ collections play an important role as a historical reference material covering not only the social situation of the time but also the history of exchange of cultural diplomacy and the change of Buddhist doctrine. In particular, some of collections of $Sh{\bar{o}}s{\bar{o}}-in$ were made in China and may have been imported or received as gifts, but many of the artifacts made in Baekje and Unified Silla are becoming more and more important. This paper examined the research status of $Sh{\bar{o}}s{\bar{o}}-in$ metal crafts of Korean and foreign scholars, and examined the association with the relics of $Sh{\bar{o}}s{\bar{o}}-in$ through metal crafts excavated from the Korean Peninsula. The research on the future direction of $Sh{\bar{o}}s{\bar{o}}-in$ collections should be summarized as follows. 1. Systematization of state-level support and single window for the research of $Sh{\bar{o}}s{\bar{o}}-in$ collections 2. Accurate listing and database of $Sh{\bar{o}}s{\bar{o}}-in$ collections 3. The positive implementation of joint research with Japan and invitation of researchers related to $Sh{\bar{o}}s{\bar{o}}-in$ collections 4. The exchange exhibition between the Korean National Treasures and the $Sh{\bar{o}}s{\bar{o}}-in$ collections 5. Expansion of the research base through the publication and support of books related to $Sh{\bar{o}}s{\bar{o}}-in$ collections.

• Journal of Digital Convergence
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• v.11 no.9
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• pp.325-331
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• 2013

The Baekje Gilt-bronze Incense Burner which was excavated in an ancient temple site in Neungsan-ri, within the City wall of Buyeo-Gun on 23rd December 1993, was a quintessence of the Bakje Arts that people could not have imagined until that time. The Baekje Gilt-bronze Incense Burner transcended 1400 years of time and space. The censer that finally came up to us delivered a kind of a powerful message to us. The power was so strong and mysterious that as if an ancestor who had been sleeping in the grave with a great silent had woken up and become alive to tell us something very precious. Baekje Gilt-bronze Incense Burner, unlike any other existing artifacts, might have a possibility that could provide an insight of the ancients' psych who once lived on our land. This kind of view from several archaeologists, therefore, made our hearts be filled with excitement and flutter. We call 21st century as an era of culture. This era requests that the culture needs to be ethnical but the culture also needs to go beyond that ethnic. In other words, a culture without an ethnic cannot exist, and a culture that puts an ethnic the very first before any other things cannot exist as well. Regaining our identities first and then embracing and harmonizing various cultures can be an wise way overcoming above problem. Hence, through this study, I intend to recognize characteristic of plasticity for Baekje Gilt-bronze Incense Burner, understand the world of Baekje people's spirit and thus provide an opportunity to shed new light on the Baekje Arts. By doing so, I would like to publicize a metal craft of Korea to the world. I also try to seek for an identity of Korea's craft culture which is receding and find a direction for the Korea's craft.

• Journal of the Korean Society of Radiology
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• v.15 no.7
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• pp.975-982
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• 2021

The purpose of this study is to evaluate the effect on the phantom for magnetic resonance imaging located nearby by partially shielding RF with a mesh made thinner than hair composed of copper, black metal, and polyester using metallic materials of titanium, which are commonly used for esophageal stents and implants in the body. Magnetic resonance images according to field of view (FOV) were analyzed in the Spin Echo T1 weighted images of TR 500 ms, TE 20 ms, NEX 1, and slice thickness 5mm using a Cardiac coil of 3T Achieva X-series. Aliasing artifact did not occur in FOV 304 mm × 304 mm, but it occurred in 250 mm × 250 mm and 170 mm × 170 mm. In FOV 170 mm × 170 mm, when a mesh was not used, the SNR was measured with 78.23, and when separated by standing a mesh in the middle, it was 215.05, and when completely shielded with a mesh, the SNR was 366.44. In addition, when completely shielded with a mesh, the aliasing artifact was also removed, and signal intensities on the left, middle and right of the image were also able to obtain homogeneous images compared to the previous two cases. In conclusion, if RF is partially shielded with a mesh, aliasing artifact can be removed, and magnetic resonance images with excellent image resolution and homogeneity can be obtained using a small FOV.

• Journal of Conservation Science
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• v.37 no.2
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• pp.144-153
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• 2021

Gwanghwadang-Wonsam was designated as National Folklore Cultural Heritage No. 52 in 1979, it is in good condition. However, a problem is the attached a phoenix insignia badge that did not exist when it was designated recently. As it became known as the only purple Wonsam artifact with "phoenix insignia", raising the need for its conservation. In this regard, scientific analysis was required to correct misinformation about designated cultural assets and restore the original designated state by analyzing the history of the Gwanghwadang-Wonsam, other relics of the phoenix insignia and its making design patterns. An X-ray fluorescence analysis was used to confirm that the Phoenix insignia's metal threads were titanium-plated silver. Phoenix insignia using titanium-plated gold thread was not identified in Gwanghwadang-Wonsam photographs in 1986, and the TiN-type membrane plating method was used in various industries in the 1990s, which can be estimated to be attached in the early and mid-1990s. Especially, the scientific analysis results from the X-ray fluorescence analysis in this study provide key evidence for conservation processing. This study demonstrates the importance of investigating relics and similar artifacts in the conservation process of inherited relics and as a precedent for restoration that corrects misinformation about designated cultural properties.

• Korean Journal of Heritage: History & Science
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• v.56 no.1
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• pp.100-116
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• 2023

The Sinamsa Temple was built in the late Goryeo Dynasty and a gilt-bronze seated Buddha is enshrined in Geungnakjeon hall in the precinct. Various damages occurred in the gilt layer of the Buddha, such as peeling of the gilt layer and deteriorating gloss. In the study, the conservation conditions of the inside and outside on the statue were accurately investigated, and the making technique was interpreted through the material characteristics and non-destructive diagnosis of the statue. As a result, it is estimated that gold-gilding layer is pure gold, coloration pigment of black is carbon, green is malachite, atacamite and verdigris, red is red lead and cinnabar, respectively. In the deterioration evaluation, peeling, cracking, break out and exfoliation of the gilt layer are confirmed as damages, but the conservation condition is relatively wholesome. However, the gloss of the gilt layer is calculated to be wider in the poorer part than the maintenance part. The ultrasonic velocity of the statue was calculated to be 1,230 to 3,987 (mean 2,608) m/s and showed a relatively wide range. In infrared thermography, peeling was not confirmed, and no special bonding marks were found. In endoscope, some biological damage and corrosion were observed on the surface of the internal metal, and sealed artifacts were identified. Manufacturing technique based on the study, it is considered that the gilt-bronze seated Buddha was cast at once, and the mold was inverted to inject molten metal.

• Korean Journal of Heritage: History & Science
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• v.53 no.1
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• pp.150-167
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• 2020

The purpose of this paper is to share the status and introduce a scientific analysis of the GeumguJagi (gilt-silver overlay porcelain, 金釦瓷器) excavated from Seongneung (石陵). This analysis aimed to highlight the GeumguJagi excavated from the Royal Tombs of Goryeo with a clear lower year (1237) and to aid research into the GeumguJagi. In 2001, the National Institute of Cultural Heritage excavated and investigated Seongneung in Heejong (熙宗). Various artifacts such as celadon, gold, bronze, and iron products were collected from the chambers inside of the tomb. There were a total of 160 celadon items including bowls, dishes, glasses, and saucers. Of those, there were 58 celadon items (including fragments) with metal frames on the openings. These consisted of bowls, plates, lids, and saucers. Until recently, in various exhibitions and papers, only one GeumguJagi was known to have been excavated from Seongneung, which was a . However, the survey identified a number of further GeumguJagis. It had been understood from inherited and excavated products that the materials used for ornaments were restricted to high-quality celadon. However, this study confirmed that the excavation of Seongneung demonstrated the use of various other materials for different models and qualities of GeumguJagis. It can be said that it is characteristic that various models and quality are confirmed together through the excavation of Seongneung. A scientific analysis was carried out that selected 12 of 58 products excavated from Seongneung. Results showed that the main component used for Geumgu ornaments was tin (Sn), and trace amounts of copper (Cu) and lead (Pb) were also commonly identified. When analyzing the material used to affix the metal fittings, this was found to be glue (膠) made from animal skins, muscle, and bones. This pattern matches that of the GeumguJagi excavated from Paju Hyeeumwonji, and the reason for this could be assumed on the basis of the contents of the 『Cheongonggaemul (天工開物)』 written by Song Ongsung (宋應星) during the Ming Dynasty. At that time, metals such as tin and copper would have been difficult to obtain. 『Xuānhwafengshi Gaolitujing (宣和奉使高麗圖經)』 shows that the use of metal was limited to certain classes; thus, the use of the GeumguJagi seems to have been centered around the royal family.

• Journal of the Institute of Convergence Signal Processing
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• v.16 no.4
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• pp.149-155
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• 2015

Tooth implant is located in oral cavity and affects neck, skull base, and facail image. These magnetic inhomogeneities are usually frequency encoding direction which cause artifacts due to change of signal strength and geometric distortion. First, to evaluate signal to noise ratio (SNR) of magnetic resonance image caused by tooth implant this study uses meat phantom which is similar to human body and is consisted with fat, muscle, and water to measure signal to noise ratio. Second, signal to noise ratio by using custom-made fixed phantom is measured, and then signal to noise ratio size of different tooth implant types is compared and analyzed. The measured signal to noise ratio values of Brushite, HSA, Metal, and RBM for meat phantom were 2.76, 2.22, 1.88, and 1.57 on T1 SE, 1.88, 1.78, 1.65, and 1.79 on T2 FLAIR, 2.28, 2.25, 2.88, and 2.05 on T2 FSE, and 2.74, 1.94, 1.67, and 1.48 on T2 GRE. The measured signal to noise ratio values of Brushite, HSA, Metal, and RBM for fixed water phantom were 1.2, 1.06, 1.12, and 1.22 on DWI, 1.93, 1.87, 1.93, and 2.06 T1 SE, 1.83, 1.76, 1.82, and 1.92 on T2 FLAIR, 1.85, 1.79, 7.86, and 1.97 on T2 FSE, and 1.97, 1.93, 1.99, and 2.06 on T2 GRE. By considering through the results, patients and dentists need to consider some impacts from testing many aspects although their main purpose of having tooth implants is a dental restoration. Moreover, depending on the tooth implant characteristics of individual patients this study results can be used as baseline data when choosing test protocol.

• Korean Journal of Heritage: History & Science
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• v.39
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• pp.243-280
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• 2006

At the Bujang-ri Site, Seosan, South Chungcheong Province, around 220 archaeological features, including semi-subterranean houses and pits of Bronze Age and semi-subterranean houses, pits, and burials of Baekje period had been identified and investigated. In Particular, mound burials No. 5 of 13 of Baekje mound burials yielding a gilt-bronze cap along with other valuable artifacts drew international scholarly attention. The gilt-bronze cap from the mound burial No. 5 is a significant archaeological data not only in the study of Baekje archaeology but also in the study of international affairs and exchange at that time. At the time of exposure, the gilt-bronze cap was already broken into a number of pieces and seriously damaged by corrosion, and hardening and urethane foam were necessary in the process of collecting its pieces. Ahead of main conservational treatments on cap, X-ray photograph and CT(computerizes tomography) were taken in order to examine interior structure of the cap and to decide appropriate treatments. In the five layers identified in the profile of cap, a textile layer was set between a metal and a layerof bark of paper birch for avoiding direct contact of the metal and the bark of paper birch. Analyses were executed for examining textile layer and a layer of fibroid material. According to microscopic analysis, while the textile layer consisted of the simplest plain fabric with one fold among three kinds of textile structures, the layer of fibroid material was mixed with two or three kinds of fibers. A comparative analysis with standard sample using FT-IR (Fourier Transform Infrared Spectroscopy) announced that both textiles and fabrics were hemp. Analysis of kind of the paper birch resulted in barks of paper birch with 15 fold. A metallographic microscope, SEM, and WDS were used for the analysis of microscopic structures of plated metal pieces. While amalgam plating was treated as a plating method, the thickness of the plated layer, a barometer of plating technique, was ranged from $1.72{\mu}m$ to $8.67{\mu}m$. The degree of purity of gold (Au) used in plating was 98% in average, and less than 1% of silver (Ag) was included.

• Progress in Medical Physics
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• v.20 no.4
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• pp.244-252
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• 2009

The purpose of this study is to compensate for susceptibility and a ferromagnetic body artifact using CFA and TGV on MR Imaging. A total of 30 patients (15 men and 15 women, mean age: 45 years) were performed on head and neck diseases. MR Unit used a 1.5T superconducting magnet (GE medical system, High Density). This study have investigated by changing with CFA and TGV (70, 90, 110, 130, 150) searching for compensation values about susceptibility and a ferromagnetic body artifact in 60 kg standards of body weight (p<0.05). As a quality results, Image qualities were obtained at different score from CFA and TGV (70, 90, 110, 130, $150=3.23{\pm}0.35$, $4.31{\pm}0.02$ $4.23{\pm}0.21$, $5.12{\pm}0.25$, $7.13{\pm}0.72$, $8.31{\pm}0.01$, $5.21{\pm}0.15$, $6.14{\pm}0.08$, $5.23{\pm}0.72$, $5.91{\pm}0.06$, p<0.05). Absolute CNRs (TG, CNRpre, CNRpost) were acquired with (70:$-1.44{\pm}0.11$, $-2.7{\pm}0.04$, 90:$-2.18{\pm}0.42$, $-4.41{\pm}0.43$, 110:$-2.89{\pm}0.43$, $-5.23{\pm}0.02$, 130:$-2.34{\pm}0.05$, $-5.26{\pm}0.01$, 150: $-2.09{\pm}0.08$, $-3.87{\pm}0.12$, p<0.05). In conclusions, this study could be compensated for metal and flow artifacts surrounding the tissues having artifact by changing CFA and TGV.