• Korean Journal of Radiology
• /
• v.22 no.7
• /
• pp.1044-1053
• /
• 2021

Objective: Motion-corrected averaging with a single-shot technique was introduced for faster acquisition of late-gadolinium-enhancement (LGE) cardiovascular magnetic resonance (CMR) imaging while free-breathing. We aimed to evaluate the image quality (IQ) of free-breathing motion-corrected single-shot LGE (moco-ss-LGE) in patients with hypertrophic cardiomyopathy (HCM). Materials and Methods: Between April and December 2019, 30 patients (23 men; median age, 48.5; interquartile range [IQR], 36.5-61.3) with HCM were prospectively enrolled. Breath-held single-shot LGE (bh-ss-LGE) and free-breathing moco-ss-LGE images were acquired in random order on a 3T MR system. Semi-quantitative IQ scores, contrast-to-noise ratios (CNRs), and quantitative size of myocardial scar were assessed on pairs of bh-ss-LGE and moco-ss-LGE. The mean ± standard deviation of the parameters was obtained. The results were compared using the Wilcoxon signed-rank test. Results: The moco-ss-LGE images had better IQ scores than the bh-ss-LGE images (4.55 ± 0.55 vs. 3.68 ± 0.45, p < 0.001). The CNR of the scar to the remote myocardium (34.46 ± 11.85 vs. 26.13 ± 10.04, p < 0.001), scar to left ventricle (LV) cavity (13.09 ± 7.95 vs. 9.84 ± 6.65, p = 0.030), and LV cavity to remote myocardium (33.12 ± 15.53 vs. 22.69 ± 11.27, p < 0.001) were consistently greater for moco-ss-LGE images than for bh-ss-LGE images. Measurements of scar size did not differ significantly between LGE pairs using the following three different quantification methods: 1) full width at half-maximum method; 23.84 ± 12.88% vs. 24.05 ± 12.81% (p = 0.820), 2) 6-standard deviation method, 15.14 ± 10.78% vs. 15.99 ± 10.99% (p = 0.186), and 3) 3-standard deviation method; 36.51 ± 17.60% vs. 37.50 ± 17.90% (p = 0.785). Conclusion: Motion-corrected averaging may allow for superior IQ and CNRs with free-breathing in single-shot LGE imaging, with a herald of free-breathing moco-ss-LGE as the scar imaging technique of choice for clinical practice.

• Journal of Preventive Medicine and Public Health
• /
• v.33 no.3
• /
• pp.334-342
• /
• 2000

Objectives . This study was conducted in order to investigate the degree of recognition, acceptability, and altitude towards day surgery of patients who were hospitalized with diseases that were candidates for day surgery; in order to analyze the average length of stay for treatment of the ailments; and to analyze the percentage of patients who could be discharged on the same day after the surgery ,using the post-anesthesia discharge scoring system. Methods : Data was collected between February 1 and March 31, 1999 from 353 patients who received surgery for cataract, adenoid hypertrophy, inguinal hernia, strabismus, ptosis, cholelithiasis, hemorrhoid, or anal fistula, at a general hospital in Daegu city. The patients were interviewed and surveyed by a post-anesthesia discharge scoring system(PADS) in order to collect data on patient condition such as vital signs, activity and mental status, pain, nausea and vomiting, surgical bleeding, intake and output after the surgery. Results : Among the 353 patients, 52.7% were after of the day surgery and 52.7% were interested in day surgery. Of the respondents, 43.1% said 'my ailment was not serious and the surgery was simple' and 30.4% said 'according to my condition rest at home was desirable' as the reasons for wanting day surgery Alternatively, 56.5% of those declining day surgery said the 'uncertainty of staying home' was the reason. The greatest concern in discharging within 24 hours after surgery was a post-op emergency situation. On the other hand, the shortened hospitalization was the largest advantage of day surgery with 39.1% responding this way, followed by the savings in hospitalization costs (25.8%) and emotional stability (13.7%). The majority of those surveyed (47.6%) believed that discharge should be determined within 1-2 days after the surgery. The average hospital stay was 3.1 days for dischargeable ailments. Pain (45.6%), nausea and vomiting (10.5%), and headache (7.9%) were the common symptoms following surgery. The percentage of patients who were able to be discharged within 24 hours after surgery revealed 95.2% were dischargeable after approximately 3 hours, 99.2% dischargeable after 12 hours, and 100% dischargeable after 24 hours. Conclusions : According to the PADS score, the cataract extract and strabismus correction patients were eligible for day surgery and the further evaluation concerning the reason for delayed recovery of the other diseases is needed.

• Korean Journal of Remote Sensing
• /
• v.30 no.1
• /
• pp.61-73
• /
• 2014

This study reviewed an application of water quality estimation using an Airborne Hyperspectral Imagery (A-HSI) and tested a part of Han River water quality (especially suspended solid) estimation with available in-situ data. The estimation of water quality was processed two methods. One is using observation data as downwelling radiance to water surface and as scattering and reflectance into water body. Other is linear regression analysis with water quality in-situ measurement and upwelling data as at-sensor radiance (or reflectance). Both methods drive meaningful results of RS estimation. However it has more effects on the auxiliary dataset as water quality in-situ measurement and water body scattering measurement. The test processed a part of Han River located Paldang-dam downstream. We applied linear regression analysis with AISA eagle hyperspectral sensor data and water quality measurement in-situ data. The result of linear regression for a meaningful band combination shows $-24.847+0.013L_{560}$ as 560 nm in radiance (L) with 0.985 R-square. To comparison with Multispectral Imagery (MSI) case, we make simulated Landsat TM by spectral resampling. The regression using MSI shows -55.932 + 33.881 (TM1/TM3) as radiance with 0.968 R-square. Suspended Solid (SS) concentration was about 3.75 mg/l at in-situ data and estimated SS concentration by A-HIS was about 3.65 mg/l, and about 5.85mg/l with MSI with same location. It shows overestimation trends case of estimating using MSI. In order to upgrade value for practical use and to estimate more precisely, it needs that minimizing sun glint effect into whole image, constructing elaborate flight plan considering solar altitude angle, and making good pre-processing and calibration system. We found some limitations and restrictions such as precise atmospheric correction, sample count of water quality measurement, retrieve spectral bands into A-HSI, adequate linear regression model selection, and quantitative calibration/validation method through the literature review and test adopted general methods.

• Progress in Medical Physics
• /
• v.16 no.2
• /
• pp.62-69
• /
• 2005

The purpose of this study has been performed to investigate the possibility of external audit program using thermoluminescence dosimetry for electron beam in korea. The TLD system consists of LiF powder, type TLD-700 read with a PCL 3 reader. In order to determine a calibration coefficient of the TLD system, the reference dosimeters are irradiated to 2 Gy in a $^{60}CO$ beam at the KFDA The irradiation is performed under reference conditions is water phantom using the IAEA standard holder for TLD of electron beam. The energy correction factor is determined for LiF powder irradiated of dose to water 2 Gy in electron beams of 6, 9, 12, 16 and 20 MeV (Varian CL 2100C). The dose is determined according to the IAEA TRS-398 and by measurement with a PTW Roos type plane-parallel chamber. The TLD for each electron energy are positioned in water at reference depth. In this study, to verify of the accuracy of dose determination by the TLD system are performed through a 'blind' TLD irradiation. The results of blind test are $2.98\%,\;3.39\%\;and\;0.01\%(1\sigma)$ at 9, 16, 20 MeV, respectively. The value generally agrees within the acceptance level of $5\%$ for electron beam. The results of this study prove the possibility of the TLD quality assurance program for electron beams. It has contributed to the improvement of clinical electron dosimetry in radiotherapy centers.

• Progress in Medical Physics
• /
• v.14 no.2
• /
• pp.124-130
• /
• 2003

Currently, as a consequence of PACS (Picture Archiving Communication System) implementation many hospitals are replacing conventional film-type interpretations of diagnostic medical images with new digital-format interpretations that can also be saved, and retrieve However, the big limitation in PACS is considered to be the lack of mobility. The purpose of this study is to determine the optimal communication packet size. This was done by considering the terms occurred in the wireless communication. After encoding medical image using JPGE2000 image compression method, This method embodied auto-error correction technique preventing the loss of packets occurred during wireless communication. A PC class server, with capabilities to load, collect data, save images, and connect with other network, was installed. Image data were compressed using JPEG2000 algorithm which supports the capability of high energy density and compression ratio, to communicate through a wireless network. Image data were also transmitted in block units coeded by JPEG2000 to prevent the loss of the packets in a wireless network. When JPGE2000 image data were decoded in a PUA (Personal Digital Assistant), it was instantaneous for a MR (Magnetic Resonance) head image of 256${\times}$256 pixels, while it took approximately 5 seconds to decode a CR (Computed Radiography) chest image of 800${\times}$790 pixels. In the transmission of the image data using a CDMA 1X module (Code-Division Multiple Access 1st Generation), 256 byte/sec was considered a stable transmission rate, but packets were lost in the intervals at the transmission rate of 1Kbyte/sec. However, even with a transmission rate above 1 Kbyte/sec, packets were not lost in wireless LAN. Current PACS are not compatible with wireless networks. because it does not have an interface between wired and wireless. Thus, the mobile JPEG2000 image viewing system was developed in order to complement mobility-a limitation in PACS. Moreover, the weak-connections of the wireless network was enhanced by re-transmitting image data within a limitations The results of this study are expected to play an interface role between the current wired-networks PACS and the mobile devices.

• Journal of Arbitration Studies
• /
• v.13 no.1
• /
• pp.169-205
• /
• 2003

Arbitration means the procedure that a party inquires a third party arbitrator for a resolution on the dispute on certain matters of interest to follow through with the commitment of the arbitration, and a series of procedures performed by the arbitrator of the Korean Commercial Arbitration Board. Arbitration is implemented in accordance with the procedure determined by the Arbitration Act and Arbitration Regulations. In the event the parties reach to the reconciliation during the process of arbitration, the reconciliation is recorded in the form of arbitration award(decision), and in the event a reconciliation is not made, the arbitrator shall make the decision on the particular case. The arbitration award(decision) for reconciliation during the arbitration procedure (Article 31 of Arbitration Act, hereinafter referred to as the 'Act') or the mediation under the Arbitration Regulation of the Korean Commercial Arbitration Board (Article 18 of the Arbitration Regulations) shall have the same effectiveness with the decision rendered by a court that, in the event a party does not perform the obligation, the enforcement document is rendered under the Rules on Enforcement Document on Mediation Statement of various dispute resolution committees of the Supreme Court to carry out the compulsory enforcement. However, in the event that the party to take on the obligation to perform under the arbitration award (decision) rendered by the arbitrator (Article 32 of the Act) does not perform without due cause, a separate enforcement decision in accordance with the procedure determined under the Civil Enforcement Act shall be obtained since the arbitration award(decision) cannot be the basis of enforcement under the Civil Enforcement Act. And, in order to enforce the judgment compulsorily in accordance with the regulations under the Civil Enforcement Act under the foreign arbitration judgment (Article 39 of the A.1), it shall fulfill the requirement determined under the Civil Litigation Act (article 217 of Civil Litigation Act) and shall obtain a separate enforcement decision in accordance with the procedure determined under the Civil Enforcement Act (Article 26 and Article 27 of Civil Enforcement Act) since the arbitration judgment of foreign country shall not be based on enforcement under the Civil Enforcement Act. It may be the issue of legislation not to recognize the arbitration award(decision) as a source of enforcement right, and provide the compulsive enforcement by recognizing it for enforcement right after obtaining the enforcement document with the decision of a court, however, not recognizing the arbitration award(decision) as the source of enforcement right is against Clause 3 of Article 31 of the Act, provisions of Article 35, Article 38 and Article 39 that recognized the validity of arbitration as equal to the final judgment of a court, and the definition that the enforcement decision of a court shall require the in compulsory enforcement under Clause 1 of Article 37 of the Act which clearly is a conflict of principle as well. Anyhow, in order to enforce the arbitration award(decision) mandatorily, the party shall bring the litigation of enforcement decision claim to the court, and the court shall deliberate with the same procedure with general civil cases under the Civil Litigation Act. During the deliberation, the party obligated under the arbitration award(decision) intended to not to undertake the obligation and delay it raises the claim and suspend the enforcement of cancelling the arbitration award(decision) on the applicable arbitration decision within 3 months from the date of receiving the authentic copy of the arbitration award(decision) or the date of receiving the authentic copy of correction, interpretation or additional decision under the Regulation of Article 34 of the Act (Clause 3 of Article 36 of the Act). This legislation to delay the sentencing of the enforcement and then to sentence the enforcement decision brings the difficulties to a party to litigation costs and time for compulsory enforcement where there is a requirement of an urgency. With the most of cases for arbitration being the special field to make the decision only with the specialized knowledge that the arbitrator shall be the specialists who have appropriate knowledge of the system and render the most reasonable and fair decision for the arbitration. However, going through the second review by a court would be most important, irreparable and serious factor to interfere with the activation of the arbitration system. The only way to activate the arbitration system that failed to secure the practicality due to such a factor, is to revise the Arbitration Act and Arbitration Regulations so that the arbitration decision shall have the right to enforce under the Rules on Enforcement Document on Mediation Statement of various dispute resolution committees of the Supreme Court.

• Journal of the Korean Association of Geographic Information Studies
• /
• v.14 no.2
• /
• pp.147-161
• /
• 2011

Korea is surrounded by sea on three sides. This country has been supplied with a variety of aquaculture products cultivated on shores. There have recently been a lot of studies to have better understanding of the correct location and quantity of aquaculture farms for seaweed, ear shells and fish that cover a wide area of sea. And it is necessary to use the geographic information system and remote sensing to detect the aquaculture farms in order to effectively manage them. This study uses higher resolution aerial images(25 centimeters) than satellite images of 2~2.5-meter resolution that have been ever used, to conduct an accuracy detection of aquaculture farming facilities. It chooses as the case study area the Wando region that has aquaculture farms for seaweed, ear shells and fish. Aerial photos of the island were obtained in this study and an image correction of them was conducted. A spatial database was then constructed in this study and the detection of aquaculture farming facilities was performed. An analysis of facilities inside and outside the permitted areas reveals that there has been an increase in the facilities of seaweed and ear shell aquaculture farms outside the permitted areas. And also it tells that because the facilities of fish aquaculture farms have turned into those of ear shell aquaculture farms, there has been a decrease in permitted facilities, facilities detected on the basis of aerial images, and facilities outside the permitted area. It will be necessary to continuously control and manage the unpermitted facilities, regarding the increase in the facilities inside and outside the permitted area for seaweed and ear shell aquaculture farms. Because the facilities of aquaculture farms cover a wide range of areas(sea) in this manner, it is more effective to depend on high resolution aerial images than a field survey to detect and calculate the facilities. This study comes up with a plan for using aerial images to detect the location and the quantity of the fish aquaculture facilities and then effectively manage them.

• The Korean Journal of Vision Science
• /
• v.20 no.4
• /
• pp.579-588
• /
• 2018

Purpose : To analyze the eyeglasses supply system for ametropic soldiers in ROK military. Methods : We investigated and analyzed the supply system of eyeglasses for the ametropic soldiers provided by the Korean military. The refractive powers and corrected visual acuity were measured for 37 ametropic soldiers who wear insert glasses for ballistic protective and gas-masks supplied by the military based on their habitual prescriptions. Full correction of refractive error was prescribed for subjects having less than 1.0 of distance visual acuity, and comparison was held for inspecting the changes in corrected visual acuity. Suggestions were provided for solving the issues regarding current supplying system, and this study investigated the applicabilities for utilizing professional optometric manpower. Results : The new glasses supplied by army for ametropic soldiers were duplicated from the glasses they worn when entering the army. The spherical equivalent refractive powers of the conventional, ballistic protective and gas-mask insert glasses supplied for 37 ametropic soldiers were $-3.47{\pm}1.69D$, $-3.52{\pm}1.66D$ and $-3.55{\pm}1.63D$, respectively, and the spherical equivalent refractive power of full corrected glasses was $-3.79{\pm}1.66D$, which showed a significant difference(p<0.05). The distant corrected visual acuity measured at high and low contrast(logMAR) of conventional, ballistic protective and gas-mask insert glasses were $0.06{\pm}0.80$, $0.21{\pm}0.82$, $0.15{\pm}0.74$, $0.34{\pm}0.89$, $0.10{\pm}0.70$ and $0.22{\pm}0.27$, respectively, while the corrected visual acuity by full corrected glasses were increased to $0.02{\pm}1.05$, $0.10{\pm}0.07$, $0.09{\pm}0.92$, $0.26{\pm}0.10$, $0.04{\pm}1.00$ and $0.19{\pm}1.00$, respectively. There was a significant difference(p<0.05) except for the case of the low contrast corrected visual acuity of the conventional and gas-mask insert glasses. The procedure for ordering, dispensing, and supplying military glasses consists of 5 steps, and it was found that approximately two weeks or more are required to supply from the initial examination. Conclusion : The procedure of supplying the military glasses showed three issues: 1) a lack of refraction for prescription system, 2) relatively long length of time required for supplying the glasses, 3) an inaccurate power of supplied glasses. In order to solve those issues, in the short term, education is necessarily required for soldiers on the measurement of the refractive powers, and in the near future, further standard procedures for prescription of glasses as well as the securement of optometric manpower are expected.

• The Journal of Korean Society for Radiation Therapy
• /
• v.32
• /
• pp.7-15
• /
• 2020

Purpose: In modern radiotherapy technology, several methods of image guided radiation therapy (IGRT) are used to deliver accurate doses to tumor target locations and normal organs, including CBCT (Cone Beam Computed Tomography) and other devices, ExacTrac System, other than CBCT equipped with linear accelerators. In previous studies comparing the two systems, positional errors were analysed rearwards using Offline-view or evaluated only with a Yaw rotation with the X, Y, and Z axes. In this study, when using CBCT and ExacTrac to perform 6 Degree of the Freedom(DoF) Online IGRT in a treatment center with two equipment, the difference between the set-up calibration values seen in each system, the time taken for patient set-up, and the radiation usefulness of the imaging device is evaluated. Materials and Methods: In order to evaluate the difference between mobile calibrations and exposure radiation dose, the glass dosimetry and Rando Phantom were used for 11 cancer patients with head circumference from March to October 2017 in order to assess the difference between mobile calibrations and the time taken from Set-up to shortly before IGRT. CBCT and ExacTrac System were used for IGRT of all patients. An average of 10 CBCT and ExacTrac images were obtained per patient during the total treatment period, and the difference in 6D Online Automation values between the two systems was calculated within the ROI setting. In this case, the area of interest designation in the image obtained from CBCT was fixed to the same anatomical structure as the image obtained through ExacTrac. The difference in positional values for the six axes (SI, AP, LR; Rotation group: Pitch, Roll, Rtn) between the two systems, the total time taken from patient set-up to just before IGRT, and exposure dose were measured and compared respectively with the RandoPhantom. Results: the set-up error in the phantom and patient was less than 1mm in the translation group and less than 1.5° in the rotation group, and the RMS values of all axes except the Rtn value were less than 1mm and 1°. The time taken to correct the set-up error in each system was an average of 256±47.6sec for IGRT using CBCT and 84±3.5sec for ExacTrac, respectively. Radiation exposure dose by IGRT per treatment was measured at 37 times higher than ExacTrac in CBCT and ExacTrac at 2.468mGy and 0.066mGy at Oral Mucosa among the 7 measurement locations in the head and neck area. Conclusion: Through 6D online automatic positioning between the CBCT and ExacTrac systems, the set-up error was found to be less than 1mm, 1.02°, including the patient's movement (random error), as well as the systematic error of the two systems. This error range is considered to be reasonable when considering that the PTV Margin is 3mm during the head and neck IMRT treatment in the present study. However, considering the changes in target and risk organs due to changes in patient weight during the treatment period, it is considered to be appropriately used in combination with CBCT.

• Journal of the Korean Association of Geographic Information Studies
• /
• v.13 no.4
• /
• pp.111-124
• /
• 2010

To monitor the environment of land surface change is considered as an important research field since those parameters are related with land use, climate change, meteorological study, agriculture modulation, surface energy balance, and surface environment system. For the change detection, many different methods have been presented for distributing more detailed information with various tools from ground based measurement to satellite multi-spectral sensor. Recently, using high resolution satellite data is considered the most efficient way to monitor extensive land environmental system especially for higher spatial and temporal resolution. In this study, we use two different spatial resolution satellites; the one is SPOT/VEGETATION with 1 km spatial resolution to detect coarse resolution of the area change and determine objective threshold. The other is Landsat satellite having high resolution to figure out detailed land environmental change. According to their spatial resolution, they show different observation characteristics such as repeat cycle, and the global coverage. By correlating two kinds of satellites, we can detect land surface change from mid resolution to high resolution. The K-mean clustering algorithm is applied to detect changed area with two different temporal images. When using solar spectral band, there are complicate surface reflectance scattering characteristics which make surface change detection difficult. That effect would be leading serious problems when interpreting surface characteristics. For example, in spite of constant their own surface reflectance value, it could be changed according to solar, and sensor relative observation location. To reduce those affects, in this study, long-term Normalized Difference Vegetation Index (NDVI) with solar spectral channels performed for atmospheric and bi-directional correction from SPOT/VEGETATION data are utilized to offer objective threshold value for detecting land surface change, since that NDVI has less sensitivity for solar geometry than solar channel. The surface change detection based on long-term NDVI shows improved results than when only using Landsat.