• Korean Journal of Acupuncture
• /
• v.31 no.1
• /
• pp.20-32
• /
• 2014

Objectives : There has been some controversy about the modulatory effects on brain function during acupuncture on each side of the same acupoint. This study was designed to investigate and compare the blood oxygen level-dependent(BOLD) responses of acupuncture on each side of ST36. Methods : Fourteen healthy subjects were recruited for imaging and received acupuncture or placebo stimulations either on the left or on the right acupoint of ST36 in each scan. For the voxel-wise statistical analysis, one sample T-test and the within-subject analysis of variance(ANOVA) test were performed using SPM8 software. Results : This study showed that acupuncture on each side of ST36 showed different BOLD signal patterns. Higher BOLD responses after acupuncture stimulations at the left ST36 compared to the right were observed mainly in the parahippocampal gyrus(BA 28), dorsolateral prefrontal cortex(DLPFC, BA 44), thalamus, culmen and claustrum. We investigated the different neural responses between rest and activation periods of placebo and acupuncture stimulations on each side of ST36. Acupuncture at the right ST36 elicited activation mainly in the insula, supplementary motor area(SMA) and anterior cingulate cortex(ACC), while acupuncture at the left ST36 elicited activation mainly in the insula, primary somatosensory cortex(SI, BA 2) and DLPFC(BA 44). Conclusions : To our knowledge, this is the first reported functional MRI study directly comparing when needling at the right and at the left side of ST36. This study's preliminary results proved to be evidence of acupuncture's different effects when performed on opposite sides of an acupoint.

• Korean Journal of Remote Sensing
• /
• v.37 no.6_3
• /
• pp.1985-1999
• /
• 2021

The purpose of this study is to apply urban heat island reduction techniques(green roof, cool roof, and cool pavements using heat insulation paint or blocks) recommended by the Environmental Protection Agency (EPA) to our study area and determine their actual effects through a comparative analysis between land cover objects. To this end, the area of Mugye-ri, Jangyu-myeon, Gimhae, Gyeongsangnam-do was selected as a study area, and measurements were taken using a drone DJI Matrice 300 RTK, which was equipped with a thermal infrared sensor FLIR Vue Pro R and a visible spectrum sensor H20T 1/2.3" CMOS, 12 MP. A total of nine heat maps, land cover objects (711) as a control group, and heat island reduction technique-applied land covering objects (180) were extracted every 1 hour and 30 minutes from 7:15 am to 7:15 pm on July 27. After calculating the effect values for each of the 180 objects extracted, the effects of each technique were integrated. Through the analysis based on daytime hours, the effect of reducing heat islands was found to be 4.71℃ for cool roof; 3.40℃ for green roof; and 0.43℃ and -0.85℃ for cool pavements using heat insulation paint and blocks, respectively. Comparing the effect by time period, it was found that the heat island reduction effect of the techniques was highest at 13:00, which is near the culmination hour, on the imaging date. Between 13:00 and 14:30, the efficiency of temperature reduction changed, with -8.19℃ for cool roof, -5.56℃ for green roof, and -1.78℃ and -1.57℃ for cool pavements using heat insulation paint and blocks, respectively. This study was a case study that verified the effects of urban heat island reduction techniques through the use of high-resolution images taken with drones. In the future, it is considered that it will be possible to present case studies that directly utilize micro-satellites with high-precision spatial resolution.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
• /
• v.26 no.3
• /
• pp.220-237
• /
• 2021

Since the functional importance of marine phytoplankton was firstly advocated from early 1880s massive data on the species composition and abundance were produced by classical microscopic observation and the advanced auto-imaging technologies. Recently, pigment composition resulted from direct chemical analysis of phytoplankton samples or indirect remote sensing could be used for the group-specific quantification, which leads us to more diversified data production methods and for more improved spatiotemporal accessibilities to the target data-gathering points. In quite a few cases of many long-term marine ecosystem monitoring programs the phytoplankton species composition and abundance was included as a basic monitoring item. The phytoplankton data could be utilized as a crucial evidence for the long-term change in phytoplankton community structure and ecological functioning at the monitoring stations. Usability of the phytoplankton data sometimes is restricted by the differences in data producers throughout the whole monitoring period. Methods for sample treatments, analyses, and species identification of the phytoplankton species could be inconsistent among the different data producers and the monitoring years. In-depth study to determine the precise quantitative values of the phytoplankton species composition and abundance might be begun by Victor Hensen in late 1880s. International discussion on the quality assurance of the marine phytoplankton data began in 1969 by the SCOR Working Group 33 of ICSU. Final report of the Working group in 1974 (UNESCO Technical Papers in Marine Science 18) was later revised and published as the UNESCO Monographs on oceanographic methodology 6. The BEQUALM project, the former body of IPI (International Phytoplankton Intercomparison) for marine phytoplankton data QA/QC under ISO standard, was initiated in late 1990. The IPI is promoting international collaboration for all the participating countries to apply the QA/QC standard established from the 20 years long experience and practices. In Korea, however, such a QA/QC standard for marine phytoplankton species composition and abundance data is not well established by law, whereas that for marine chemical data from measurements and analysis has been already set up and managed. The first priority might be to establish a QA/QC standard system for species composition and abundance data of marine phytoplankton, then to be extended to other functional groups at the higher consumer level of marine food webs.

• Journal of the Korean Society of Radiology
• /
• v.83 no.1
• /
• pp.149-161
• /
• 2022

Purpose To investigate the correlation between computer-aided diagnosis (CAD) parameters in 3-tesla (T) MRI and pathologic immunohistochemical (IHC) markers in invasive carcinoma of no special type (NST). Materials and Methods A total of 94 female who were diagnosed with NST carcinoma and underwent 3T MRI using CAD, from January 2018 to April 2019, were included. The relationship between angiovolume, curve peak, and early and late profiles of dynamic enhancement from CAD with pathologic IHC markers and molecular subtypes were retrospectively investigated using Dwass, Steel, Critchlow-Fligner multiple comparison analysis, and univariate binary logistic regression analysis. Results In NST carcinoma, a higher angiovolume was observed in tumors of higher nuclear and histologic grades and in lymph node (LN) (+), estrogen receptor (ER) (-), progesterone receptor (PR) (-), human epidermal growth factor 2 (HER2) (+), and Ki-67 (+) tumors. A high rate of delayed washout and a low rate of delayed persistence were observed in Ki-67 (+) tumors. In the binary logistic regression analysis of NST carcinoma, a high angiovolume was significantly associated with a high nuclear and histologic grade, LN (+), ER (-), PR (-), HER2 (+) status, and non-luminal subtypes. A high rate of washout and a low rate of persistence were also significantly correlated with the Ki-67 (+) status. Conclusion Angiovolume and delayed washout/persistent rate from CAD parameters in contrast enhanced breast MRI correlated with predictive IHC markers. These results suggest that CAD parameters could be used as clinical prognostic, predictive factors.

• Dementia and Neurocognitive Disorders
• /
• v.23 no.1
• /
• pp.54-66
• /
• 2024

Background and Purpose: Dementia subtypes, including Alzheimer's dementia (AD), dementia with Lewy bodies (DLB), and frontotemporal dementia (FTD), pose diagnostic challenges. This review examines the effectiveness of ¹⁸F-Fluorodeoxyglucose Positron Emission Tomography (¹⁸F-FDG PET) in differentiating these subtypes for precise treatment and management. Methods: A systematic review following Preferred Reporting Items for Systematic reviews and Meta-Analyses guidelines was conducted using databases like PubMed and Embase to identify studies on the diagnostic utility of ¹⁸F-FDG PET in dementia. The search included studies up to November 16, 2022, focusing on peer-reviewed journals and applying the goldstandard clinical diagnosis for dementia subtypes. Results: From 12,815 articles, 14 were selected for final analysis. For AD versus FTD, the sensitivity was 0.96 (95% confidence interval [CI], 0.88-0.98) and specificity was 0.84 (95% CI, 0.70-0.92). In the case of AD versus DLB, ¹⁸F-FDG PET showed a sensitivity of 0.93 (95% CI 0.88-0.98) and specificity of 0.92 (95% CI, 0.70-0.92). Lastly, when differentiating AD from non-AD dementias, the sensitivity was 0.86 (95% CI, 0.80-0.91) and the specificity was 0.88 (95% CI, 0.80-0.91). The studies mostly used case-control designs with visual and quantitative assessments. Conclusions: ¹⁸F-FDG PET exhibits high sensitivity and specificity in differentiating dementia subtypes, particularly AD, FTD, and DLB. This method, while not a standalone diagnostic tool, significantly enhances diagnostic accuracy in uncertain cases, complementing clinical assessments and structural imaging.

• The Korean Journal of Nuclear Medicine Technology
• /
• v.14 no.2
• /
• pp.21-25
• /
• 2010

Purpose: For better PET imaging with accuracy the transmission scanning is inevitably required for attenuation correction. The attenuation is affected by condition of acquisition and patient position, consequently quantitative accuracy may be decreased in emission scan imaging. In this paper, the present study aims at providing the measurement for attenuation varying with the positions of the patient's arm in whole body PET/CT, further performing the comparative analysis over its SUV changes. Materials and Methods: NEMA 1994 PET phantom was filled with $^{18}F$-FDG and the concentration ratio of insert cylinder and background water fit to 4:1. Phantom images were acquired through emission scanning for 4min after conducting transmission scanning by using CT. In an attempt to acquire image at the state that the arm of the patient was positioned at the lower of ahead, image was acquired in away that two pieces of Teflon inserts were used additionally by fixing phantoms at both sides of phantom. The acquired imaged at a were reconstructed by applying the iterative reconstruction method (iteration: 2, subset: 28) as well as attenuation correction using the CT, and then VOI was drawn on each image plane so as to measure CT number and SUV and comparatively analyze axial uniformity (A.U=Standard deviation/Average SUV) of PET images. Results: It was found from the above phantom test that, when comparing two cases of whether Teflon insert was fixed or removed, the CT number of cylinder increased from -5.76 HU to 0 HU, while SUV decreased from 24.64 to 24.29 and A.U from 0.064 to 0.052. And the CT number of background water was identified to increase from -6.14 HU to -0.43 HU, whereas SUV decreased from 6.3 to 5.6 and A.U also decreased from 0.12 to 0.10. In addition, as for the patient image, CT number was verified to increase from 53.09 HU to 58.31 HU and SUV decreased from 24.96 to 21.81 when the patient's arm was positioned over the head rather than when it was lowered. Conclusion: When arms up protocol was applied, the SUV of phantom and patient image was decreased by 1.4% and 9.2% respectively. With the present study it was concluded that in case of PET/CT scanning against the whole body of a patient the position of patient's arm was not so much significant. Especially, the scanning under the condition that the arm is raised over to the head gives rise to more probability that the patient is likely to move due to long scanning time that causes the increase of uptake of $^{18}F$-FDG of brown fat at the shoulder part together with increased pain imposing to the shoulder and discomfort to a patient. As regarding consideration all of such factors, it could be rationally drawn that PET/CT scanning could be made with the arm of the subject lowered.

• Radiation Oncology Journal
• /
• v.28 no.3
• /
• pp.155-165
• /
• 2010

Purpose: In order to evaluate the positional uncertainty of internal organs during radiation therapy for treatment of liver cancer, we measured differences in inter- and intra-fractional variation of the tumor position and tidal amplitude using 4-dimentional computed radiograph (DCT) images and gated orthogonal setup kilovolt (KV) images taken on every treatment using the on board imaging (OBI) and real time position management (RPM) system. Materials and Methods: Twenty consecutive patients who underwent 3-dimensional (3D) conformal radiation therapy for treatment of liver cancer participated in this study. All patients received a 4DCT simulation with an RT16 scanner and an RPM system. Lipiodol, which was updated near the target volume after transarterial chemoembolization or diaphragm was chosen as a surrogate for the evaluation of the position difference of internal organs. Two reference orthogonal (anterior and lateral) digital reconstructed radiograph (DRR) images were generated using CT image sets of 0% and 50% into the respiratory phases. The maximum tidal amplitude of the surrogate was measured from 3D conformal treatment planning. After setting the patient up with laser markings on the skin, orthogonal gated setup images at 50% into the respiratory phase were acquired at each treatment session with OBI and registered on reference DRR images by setting each beam center. Online inter-fractional variation was determined with the surrogate. After adjusting the patient setup error, orthogonal setup images at 0% and 50% into the respiratory phases were obtained and tidal amplitude of the surrogate was measured. Measured tidal amplitude was compared with data from 4DCT. For evaluation of intra-fractional variation, an orthogonal gated setup image at 50% into the respiratory phase was promptly acquired after treatment and compared with the same image taken just before treatment. In addition, a statistical analysis for the quantitative evaluation was performed. Results: Medians of inter-fractional variation for twenty patients were 0.00 cm (range, -0.50 to 0.90 cm), 0.00 cm (range, -2.40 to 1.60 cm), and 0.00 cm (range, -1.10 to 0.50 cm) in the X (transaxial), Y (superior-inferior), and Z (anterior-posterior) directions, respectively. Significant inter-fractional variations over 0.5 cm were observed in four patients. Min addition, the median tidal amplitude differences between 4DCTs and the gated orthogonal setup images were -0.05 cm (range, -0.83 to 0.60 cm), -0.15 cm (range, -2.58 to 1.18 cm), and -0.02 cm (range, -1.37 to 0.59 cm) in the X, Y, and Z directions, respectively. Large differences of over 1 cm were detected in 3 patients in the Y direction, while differences of more than 0.5 but less than 1 cm were observed in 5 patients in Y and Z directions. Median intra-fractional variation was 0.00 cm (range, -0.30 to 0.40 cm), -0.03 cm (range, -1.14 to 0.50 cm), 0.05 cm (range, -0.30 to 0.50 cm) in the X, Y, and Z directions, respectively. Significant intra-fractional variation of over 1 cm was observed in 2 patients in Y direction. Conclusion: Gated setup images provided a clear image quality for the detection of organ motion without a motion artifact. Significant intra- and inter-fractional variation and tidal amplitude differences between 4DCT and gated setup images were detected in some patients during the radiation treatment period, and therefore, should be considered when setting up the target margin. Monitoring of positional uncertainty and its adaptive feedback system can enhance the accuracy of treatments.

• The Journal of Korean Society for Radiation Therapy
• /
• v.31 no.1
• /
• pp.33-41
• /
• 2019

Purpose : To evaluate the effectiveness of Jaw-tracking(JT) technique in Intensity-modulated radiation therapy(IMRT) and Volumetric-modulated arc therapy(VMAT) for radiation therapy of esophageal cancer by analyzing volume dose of perimetrical normal organs along with the low-dose volume regions. Materials and Method: A total of 27 patients were selected who received radiation therapy for esophageal cancer with using $VitalBeam^{TM}$(Varian Medical System, U.S.A) in our hospital. Using Eclipse system(Ver. 13.6 Varian, U.S.A), radiation treatment planning was set up with Jaw-tracking technique(JT) and Non-Jaw-tracking technique(NJT), and was conducted for the patients with T-shaped Planning target volume(PTV), including Supraclavicular lymph nodes(SCL). PTV was classified into whether celiac area was included or not to identify the influence on the radiation field. To compare the treatment plans, Organ at risk(OAR) was defined to bilateral lung, heart, and spinal cord and evaluated for Conformity index(CI) and Homogeneity index(HI). Portal dosimetry was performed to verify a clinical application using Electronic portal imaging device(EPID) and Gamma analysis was performed with establishing thresholds of radiation field as a parameter, with various range of 0 %, 5 %, and 10 %. Results: All treatment plans were established on gamma pass rates of 95 % with 3 mm/3 % criteria. For a threshold of 10 %, both JT and NJT passed with rate of more than 95 % and both gamma passing rate decreased more than 1 % in IMRT as the low dose threshold decreased to 5 % and 0 %. For the case of JT in IMRT on PTV without celiac area, $V_5$ and $V_{10}$ of both lung showed a decrease by respectively 8.5 % and 5.3 % in average and up to 14.7 %. A $D_{mean}$ decreased by $72.3{\pm}51cGy$, while there was an increase in radiation dose reduction in PTV including celiac area. A $D_{mean}$ of heart decreased by $68.9{\pm}38.5cGy$ and that of spinal cord decreased by $39.7{\pm}30cGy$. For the case of JT in VMAT, $V_5$ decreased by 2.5 % in average in lungs, and also a little amount in heart and spinal cord. Radiation dose reduction of JT showed an increase when PTV includes celiac area in VMAT. Conclusion: In the radiation treatment planning for esophageal cancer, IMRT showed a significant decrease in $V_5$, and $V_{10}$ of both lungs when applying JT, and dose reduction was greater when the irradiated area in low-dose field is larger. Therefore, IMRT is more advantageous in applying JT than VMAT for radiation therapy of esophageal cancer and can protect the normal organs from MLC leakage and transmitted doses in low-dose field.

• Nuclear Medicine and Molecular Imaging
• /
• v.42 no.1
• /
• pp.8-16
• /
• 2008

Purpose: To assess the effect of extracranial-intracranial (EC-IC) bypass surgery on hemodynamic improvement, we evaluated serial regional cerebral hemodynamic change of the middle cerebral artery (MCA) in symptomatic patients with atherosclerotic occlusion of the internal carotid artery (ICA) or MCA using $^{99m}Tc$-ECD acetazolamide stress brain perfusion SPECT (Acetazolamide SPECT). Materials and Methods: The patients who had suffered a recent stroke with atherosclerotic ICA or MCA occlusion underwent EC-IC bypass surgery and Acetazolamide SPECT at 1 week before and three to six months after surgery. For image analysis, attenuation corrected images were spatially normalized to SPECT templates with SPM2. Anatomical automated labeling was applied to calculate mean counts of each Volume-Of-Interest (VOI). Seven VOIs of bilateral frontal, parietal, temporal regions of the MCA territory and the ipsilateral cerebellum were defined. Using mean counts of 7 VOIs, cerebral perfusion index and perfusion reserve index were calculated. Results: Seventeen patients (M:F =12:5, mean age $53{\pm}2yr$) were finally included in the analysis. The cerebral blood flow of the parietal region increased at 1 week (p = 0.003) and decreased to the preoperative level at 3-6 months (p = 0.003). The cerebrovascular reserve of the frontal and parietal regions increased significantly at 1 week after surgery (p<0.01) and improved further at 3-6 months. Conclusion: Cerebrovascular reserve of the MCA territory was significantly improved at early postoperative period after EC-IC bypass and kept improved state during long-term follow-up, although cerebral blood flow did not significantly improved. Therefore, cerebrovascular reserve may be a good indicator of postoperative hemodynamic improvement resulted from bypass effect.

• Journal of the Korean earth science society
• /
• v.38 no.4
• /
• pp.283-292
• /
• 2017

In this study, the empirical models were established to estimate the concentrations of surface-level $PM_{2.5}$ over Seoul, Korea from 1 January 2012 to 31 December 2013. We used six different multiple linear regression models with aerosol optical thickness (AOT), ${\AA}ngstr{\ddot{o}}m$ exponents (AE) data from Moderate Resolution Imaging Spectroradiometer (MODIS) aboard Terra and Aqua satellites, meteorological data, and planetary boundary layer depth (PBLD) data. The results showed that $M_6$ was the best empirical model and AOT, AE, relative humidity (RH), wind speed, wind direction, PBLD, and air temperature data were used as input data. Statistical analysis showed that the result between the observed $PM_{2.5}$ and the estimated $PM_{2.5}$ concentrations using $M_6$ model were correlations (R=0.62) and root square mean error ($RMSE=10.70{\mu}gm^{-3}$). In addition, our study show that the relation strongly depends on the seasons due to seasonal observation characteristics of AOT, with a relatively better correlation in spring (R=0.66) and autumntime (R=0.75) than summer and wintertime (R was about 0.38 and 0.56). These results were due to cloud contamination of summertime and the influence of snow/ice surface of wintertime, compared with those of other seasons. Therefore, the empirical multiple linear regression model used in this study showed that the AOT data retrieved from the satellite was important a dominant variable and we will need to use additional weather variables to improve the results of $PM_{2.5}$. Also, the result calculated for $PM_{2.5}$ using empirical multi linear regression model will be useful as a method to enable monitoring of atmospheric environment from satellite and ground meteorological data.