• Title/Summary/Keyword: Quantitative CT

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Quantitative Analysis of Regional Cerebral Blood Flow using $^{99m}Tc-HMPAO$ SPECT in Parkinson's Disease (파킨슨병에서 $^{99m}Tc-HMPAO$ SPECT를 이용한 국소뇌혈류의 정량적 분석)

  • Lee, Myung-Chul;Bae, Sang-Kyun;Lee, Myung-Hae;Chung, June-Key;Koh, Chang-Soon;Roh, Jae-Kyu;Myung, Ho-Jin
    • The Korean Journal of Nuclear Medicine
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    • v.26 no.2
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    • pp.251-256
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    • 1992
  • Regional cerebral blood flow were measured in 10 patients with Parkinson's disease and 12 normal persons using $^{99m}Tc-HMPAO$ SPECT. Reconstructed images were interpreted qualitatively and were compared with those findings of CT. For the quantitative analysis, six pairs of region of interest matched with the perfusion territories of large cerebral arteries and cerebellar hemisphere were determined. From the count values, indices showing the degree of asymmetry between right and left cerebral or cerebellar hemisphere, cerebral asymmetry index (ASI) and percent index of cerebellar asymmetry (PIA), and an index showing change of each region, region to cerebellum ratio (RCR) were obtained. ASI of normal persons and patients were $0.082{\pm}0.033$ and $0.108{\pm}0.062$, respectively and PIA were $-0.4{\pm}0.7%$ and $-0.7{\pm}1.0%$, respectively, which showed no statistically significant difference between normal persons and patients. Among 10 RCR's, those of both regions of basal ganglia and both regions of anterior cerebral artery were significantly reduced. We concluded that the most significant reduction of regional cerebral blood flow in patients with Parkinson's disease was observed in the regions of basal ganglia and in the regions of anterior cerebral artery, and the degree of change in hemispheric blood flow was similar in both hemisphere.

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Selection of suitable reference gene for gene expression studies of porcine ovaries under different conditions in quantitative reverse transcription polymerase chain reaction assay

  • Kim, Hwan-Deuk;Jeon, Hye-Jin;Jang, Min;Bae, Seul-Gi;Yun, Sung-Ho;Han, Jee-Eun;Kim, Seung-Joon;Lee, Won-Jae
    • Journal of Animal Reproduction and Biotechnology
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    • v.37 no.2
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    • pp.96-105
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    • 2022
  • The ovary undergoes substantial physiological changes along with estrus phase to mediate negative/positive feedback to the upstream reproductive tissues and to play a role in producing a fertilizable oocyte in the developing follicles. However, the disorder of estrus cycle in female can lead to diseases, such as cystic ovary which is directly associated with decline of overall reproductive performance. In gene expression studies of ovaries, quantitative reverse transcription polymerase chain reaction (qPCR) assay has been widely applied. During this assay, although normalization of target genes against reference genes (RGs) has been indispensably conducted, the expression of RGs is also variable in each experimental condition which can result in false conclusion. Because the understanding for stable RG in porcine ovaries was still limited, we attempted to assess the stability of RGs from the pool of ten commonly used RGs (18S, B2M, PPIA, RPL4, SDHA, ACTB, GAPDH, HPRT1, YWHAZ, and TBP) in the porcine ovaries under different estrus phase (follicular and luteal phase) and cystic condition, using stable RG-finding programs (geNorm, Normfinder, and BestKeeper). The significant (p < 0.01) differences in Ct values of RGs in the porcine ovaries under different conditions were identified. In assessing the stability of RGs, three programs comprehensively agreed that TBP and YWHAZ were suitable RGs to study porcine ovaries under different conditions but ACTB and GAPDH were inappropriate RGs in this experimental condition. We hope that these results contribute to plan the experiment design in the field of reproductive physiology in pigs as reference data.

Image-Based Assessment and Clinical Significance of Absorbed Radiation Dose to Tumor in Repeated High-Dose $^{131}I$ Anti-CD20 Monoclonal Antibody (Rituximab) Radioimmunotherapy for Non-Hodgkin's Lymphoma (반복적인 $^{131}I$ rituximab 방사면역치료를 시행 받은 비호지킨 림프종 환자 군에서 종양 부위의 영상기반 방사선 흡수선량 평가와 임상적 의의)

  • Byun, Byung-Hyun;Kim, Kyeong-Min;Woo, Sang-Keun;Choi, Tae-Hyun;Kang, Hye-Jin;Oh, Dong-Hyun;Kim, Byeong-Il;Cheon, Gi-Jeong;Choi, Chang-Woon;Lim, Sang-Moo
    • Nuclear Medicine and Molecular Imaging
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    • v.43 no.1
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    • pp.60-71
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    • 2009
  • Purpose: We assessed the absorbed dose to the tumor ($Dose_{tumor}$) by using pretreatment FDG-PET and whole-body (WB) planar images in repeated radioimmunotherapy (RIT) with $^{131}I$ rituximab for NHL. Materials and Methods: Patients with NHL (n=4) were administered a therapeutic dose of $^{131}I$ rituximab. Serial WB planar images alter RIT were acquired and overlaid to the coronal maximum intensity projection (MIP) PET image before RIT. On registered MIP PET and WB planar images, 2D-ROls were drawn on the region of tumor (n=7) and left medial thigh as background, and $Dose_{tumor}$ was calculated. The correlation between $Dose_{tumor}$ and the CT-based tumor volume change alter RIT was analyzed. The differences of $Dose_{tumor}$ and the tumor volume change according to the number of RIT were also assessed. Results: The values of absorbed dose were $397.7{\pm}646.2cGy$ ($53.0{\sim}2853.0cGy$). The values of CT-based tumor volume were $11.3{\pm}9.1\;cc$ ($2.9{\sim}34.2cc$), and the % changes of tumor volume before and alter RIT were $-29.8{\pm}44.3%$ ($-100.0%{\sim}+42.5%$), respectively. $Dose_{tumor}$ and the tumor volume change did not show the linear relationship (p>0.05). $Dose_{tumor}$ and the tumor volume change did not correlate with the number of repeated administration (p>0.05). Conclusion: We could determine the position and contour of viable tumor by MIP PET image. And, registration of PET and gamma camera images was possible to estimate the quantitative values of absorbed dose to tumor.

Evaluation of Radioactivity Concentration According to Radioactivity Uptake on Image Acquisition of PET/CT 2D and 3D (PET/CT 2D와 3D 영상 획득에서 방사능 집적에 따른 방사능 농도의 평가)

  • Park, Sun-Myung;Hong, Gun-Chul;Lee, Hyuk;Kim, Ki;Choi, Choon-Ki;Seok, Jae-Dong
    • The Korean Journal of Nuclear Medicine Technology
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    • v.14 no.1
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    • pp.111-114
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    • 2010
  • Purpose: There has been recent interest in the radioactivity uptake and image acquisition of radioactivity concentration. The degree of uptake is strongly affected by many factors containing $^{18}F$-FDG injection volume, tumor size and the density of blood glucose. Therefore, we investigated how radioactivity uptake in target influences 2D or 3D image analysis and elucidate radioactivity concentration that mediate this effect. This study will show the relationship between the radioactivity uptake and 2D,3D image acquisition on radioactivity concentration. Materials and Methods: We got image with 2D and 3D using 1994 NEMA PET phantom and GE Discovery(GE, U.S.A) STe 16 PET/CT setting the ratio of background and hot sphere's radioactivity concentration as being a standard of 1:2, 1:4, 1:8, 1:10, 1:20, and 1:30 respectively. And we set 10 minutes for CT attenuation correction and acquisition time. For the reconstruction method, we applied iteration method with twice of the iterative and twenty times subset to both 2D and 3D respectively. For analyzing the images, We set the same ROI at the center of hot sphere and the background radioactivity. We measured the radioactivity count of each part of hot sphere and background, and it was comparative analyzed. Results: The ratio of hot sphere's radioactivity density and the background radioactivity with setting ROI was 1:1.93, 1:3.86, 1:7.79, 1:8.04, 1:18.72, and 1:26.90 in 2D, and 1:1.95, 1:3.71, 1:7.10, 1:7.49, 1:15.10, and 1:23.24 in 3D. The differences of percentage were 3.50%, 3.47%, 8.12%, 8.02%, 10.58%, and 11.06% in 2D, the minimum differentiation was 3.47%, and the maximum one was 11.06%. In 3D, the difference of percentage was 3.66%, 4.80%, 8.38%, 23.92%, 23.86%, and 22.69%. Conclusion: The difference of accumulated concentrations is significantly increased following enhancement of radioactivity concentration. The change of radioactivity density in 2D image is affected by less than 3D. For those reasons, when patient is examined as follow up scan with changing the acquisition mode, scan should be conducted considering those things may affect to the quantitative analysis result and take into account these differences at reading.

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Assessment of Acquisition Protocols for Post-Radioembolization Yttrium-90 PET/CT: Initial Study (90Y SIR-Spheres를 사용한 암의 간 전이치료에서 PET 영상획득에 관한 초기연구)

  • Bahn, Young Kag;Oh, Shin Hyun;Kim, Jung Yul;Lee, Seung Jae;Park, Joon Young;Shin, Heui Soon;Lim, Han Sang;Kim, Jae Sam
    • The Korean Journal of Nuclear Medicine Technology
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    • v.18 no.1
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    • pp.89-93
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    • 2014
  • Purpose: We investigated the quantitative evaluation of PET/CT images for evaluation after treatment in the treatment of liver metastasis of cancer with $^{90}YSIR$-Sphere. Materials and Methods: Confirmed the correlation between the measured counts was expressed by setting a region of interest from the image and a measure of the dose calibrator to see a correlation diagram of an image in a PET of $^{90}Y$. A portion uptake coefficients between PET images were acquired for 20 minutes LIST mode in 15 patients treated for liver metastasis of cancer using $^{90}Y$ SIR-Spheres high, intermediate portion, a lower portion, three measuring the coefficient of the region of interest is divided into parts, we studied the conditions for proper image acquisition. Results: Coefficient of sites that set the region of interest of the PET image and the measured counts of $^{90}Yappears$ that there is a correlation diagram statistically, ($R^2=0.956$), correlation diagram from the PET image of $^{90}Yis$, PET coefficient the coefficients of all regions of interest were increased in proportion to the image acquisition time, partial ROI coefficients of the PET image is higher about 10 minutes on average, about 14 minutes on average, the central portion is lower part 19 minute average in, confirmed the equilibrium of the standard deviation. Conclusion: Using the isotope $^{90}Y$, it is suitable to obtain a PET image, to obtain the time of proper image, the evaluation of PET/CT images, using the $^{90}Y$ SIR-Spheres and that in the treatment of liver metastases of cancer, it is useful for assessing treatment.

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Low-Tube-Voltage CT Urography Using Low-Concentration-Iodine Contrast Media and Iterative Reconstruction: A Multi-Institutional Randomized Controlled Trial for Comparison with Conventional CT Urography

  • Kim, Sang Youn;Cho, Jeong Yeon;Lee, Joongyub;Hwang, Sung Il;Moon, Min Hoan;Lee, Eun Ju;Hong, Seong Sook;Kim, Chan Kyo;Kim, Kyeong Ah;Park, Sung Bin;Sung, Deuk Jae;Kim, Yongsoo;Kim, You Me;Jung, Sung Il;Rha, Sung Eun;Kim, Dong Won;Lee, Hyun;Shim, Youngsup;Hwang, Inpyeong;Woo, Sungmin;Choi, Hyuck Jae
    • Korean Journal of Radiology
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    • v.19 no.6
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    • pp.1119-1129
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    • 2018
  • Objective: To compare the image quality of low-tube-voltage and low-iodine-concentration-contrast-medium (LVLC) computed tomography urography (CTU) with iterative reconstruction (IR) with that of conventional CTU. Materials and Methods: This prospective, multi-institutional, randomized controlled trial was performed at 16 hospitals using CT scanners from various vendors. Patients were randomly assigned to the following groups: 1) the LVLC-CTU (80 kVp and 240 mgI/mL) with IR group and 2) the conventional CTU (120 kVp and 350 mgI/mL) with filtered-back projection group. The overall diagnostic acceptability, sharpness, and noise were assessed. Additionally, the mean attenuation, signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), and figure of merit (FOM) in the urinary tract were evaluated. Results: The study included 299 patients (LVLC-CTU group: 150 patients; conventional CTU group: 149 patients). The LVLC-CTU group had a significantly lower effective radiation dose ($5.73{\pm}4.04$ vs. $8.43{\pm}4.38mSv$) compared to the conventional CTU group. LVLC-CTU showed at least standard diagnostic acceptability (score ${\geq}3$), but it was non-inferior when compared to conventional CTU. The mean attenuation value, mean SNR, CNR, and FOM in all pre-defined segments of the urinary tract were significantly higher in the LVLC-CTU group than in the conventional CTU group. Conclusion: The diagnostic acceptability and quantitative image quality of LVLC-CTU with IR are not inferior to those of conventional CTU. Additionally, LVLC-CTU with IR is beneficial because both radiation exposure and total iodine load are reduced.

A Measurement Method for Cervical Neural Foraminal Stenosis Ratio using 3-dimensional CT (3차원 컴퓨터단층촬영상을 이용한 신경공 협착률 측정방법)

  • Kim, Yon-Min
    • Journal of the Korean Society of Radiology
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    • v.14 no.7
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    • pp.975-980
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    • 2020
  • Cervical neural foraminal stenosis is a very common spinal disease that affects a relatively large number of people of all ages. However, since imaging methods that quantitatively provide neural foraminal stenosis are lacking, this study attempts to present quantitative measurement results by reconstructing 3D computed tomography images. Using a 3D reconstruction software, the surrounding bones were removed, including the spinous process, transverse process, and lamina of the cervical spine so that the neural foramen were well observed. Using Image J, a region of interest including the neural foramen area of the 3D image was set, and the number of pixels of the neural foramen area was measured. The neural foramen area was calculated by multiplying the number of measured pixels by the pixel size. In order to measure the widest area of the neural foramen, it was measured between 40-50 degrees in the opposite direction and 15-20 degrees toward the head. The measured cervical neural foramen area showed consistent measurement values. The largest measured area of the right neural foramen C5-6 was 12.21 ㎟, and after 2 years, the area was measured to be 9.95 ㎟, indicating that 18% stenosis had progressed. Since 3D reconstruction using axial CT scan images, no additional radiation exposure is required, and the area of stenosis can be objectively presented. In addition, it is good to explain to patients with neural stenosis while viewing 3D images, and it is considered a good method to be used in the evaluation of the progression of stenosis and post-operative evaluation.

Exploring the Types of Elementary Students' Scientific Creativity According to the Structural Relationship between Creative Process and Product (창의 과정과 산물의 구조적 관계에 따른 초등학생의 과학 창의성 유형 탐색)

  • Kim, Minju;Lim, Chaeseong
    • Journal of The Korean Association For Science Education
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    • v.42 no.1
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    • pp.33-49
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    • 2022
  • This study aims to explore, using both quantitative and qualitative data analyzing the structural relationship between creative process and product, the types of elementary students' scientific creativity. For this, 105 fifth-graders responded to a scientific creativity test that assesses creative process and product, and four students who scored the highest were interviewed. In the interview, they were asked about the cognitive process they used in generating the creative product. Then, correlation analysis and structural equation modeling were used, along with the interview data, to type the students. The main findings of the study are as follows. First, the structural equation modeling of creative process and product gave satisfactory results in absolute and incremental fit indexes. Second, among the three components of creative process - knowledge, inquiry skill-observation, and creative thinking skills -, only creative thinking skills had significant effects on creative product. Third, divergent thinking skills had the strongest correlation with the creative product, followed by convergent thinking skills. Associational thinking skills did not have significant correlation. Fourth, elementary students' scientific creativity could be categorized into Creative Type, Useful Type, Original Type, and Non-creative Type, based on their creative product. The Non-creative Type could be further classified into Common Type, Repetitive Type, Non-response Type, Irrelevant Type, and Abstract Type. Fifth, most students used either knowledge or observation in their creative process, making them either Knowledge-oriented Type or Observation-oriented Type. In addition, there were DT Type, DT-CT Type, and DT-CT-AT Type among the students, based on the kinds of creative thinking skills they mainly used in the process. This study provides implications for educators and researchers in scientific creativity education.

Stability Study for Herbal Drug According to Storage Conditions and Periods (탕약의 실온과 냉장보관 및 기간별 안정성에 대한 실험적 연구)

  • Son, Jin-Young;Shin, Jang-Woo;Son, Chang-Gue
    • The Journal of Korean Medicine
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    • v.30 no.2
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    • pp.127-132
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    • 2009
  • Objectives: This study aimed to investigate the stability of a decoction using three herbal plants and their major components according to the storage conditions and periods. Materials and Methods: A three-herb mixture (1:1:1) of Glycyrrhiza uralensis Fischer, Artemisia capillaris Thunberg, and Poncirus trifoliata Rafinesqui was decocted and kept at room temperature ($25{\pm}2^{\circ}C$) or cold temperature ($4^{\circ}C$) for 0, 2, 4 or 8 weeks in liquid form in a plastic pack under dark conditions. At time points given, they were lyophilized. 200 mg of powdered samples were dissolved in 1 mL of 90% methanol and then applied to a high performance thin layer chromatography (HPTLC) with glycyrrhizin, 6,7-dimethoxycoumarin or poncirin for quantitative or qualitative analysis. Results: There were no gross changes in HPTLC-based compositional band-patterns of the three herbal mixture according to the storage conditions and period. The major components of each herb, glycyrrhizin, 6,7-dimethoxycoumarin and poncirin, showed slight time-dependent reduction in their contents both at room and cold temperature for 8 weeks. Conclusion: We could conclude that the current herbal decoction is generally safe for the stability at both RT or CT for at least 8 weeks. Nevertheless, we proposed that further advanced studies are required for more multiple herbal mixtures and longer storage periods.

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Automated 2D/3D Image Matching Technique with Dual X-ray Images for Estimation of 3D In Vivo Knee Kinematics

  • Kim, Yoon-Hyuk;Phong, Le Dinh;Kim, Kyung-Soo;Kim, Tae-Seong
    • Journal of Biomedical Engineering Research
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    • v.29 no.6
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    • pp.431-435
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    • 2008
  • Quantitative information of a three dimensional(3D) kinematics of joint is very useful in knee joint surgery, understanding how knee kinematics related to joint injury, impairment, surgical treatment, and rehabilitation. In this paper, an automated 2D/3D image matching technique was developed to estimate the 3D in vivo knee kinematics using dual X-ray images. First, a 3D geometric model of the knee was reconstructed from CT scan data. The 3D in vivo position and orientation of femoral and tibial components of the knee joint could be estimated by minimizing the pixel by pixel difference between the projection images from the developed 3D model and the given X-ray images. The accuracy of the developed technique was validated by an experiment with a cubic phantom. The present 2D/3D image matching technique for the estimation of in vivo joint kinematics could be useful for pre-operative planning as well as post-operative evaluation of knee surgery.