• Title/Summary/Keyword: Evaluation contrast effect

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Performance Evaluation of Reconstruction Algorithms for DMIDR (DMIDR 장치의 재구성 알고리즘 별 성능 평가)

  • Kwak, In-Suk;Lee, Hyuk;Moon, Seung-Cheol
    • The Korean Journal of Nuclear Medicine Technology
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    • v.23 no.2
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    • pp.29-37
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    • 2019
  • Purpose DMIDR(Discovery Molecular Imaging Digital Ready, General Electric Healthcare, USA) is a PET/CT scanner designed to allow application of PSF(Point Spread Function), TOF(Time of Flight) and Q.Clear algorithm. Especially, Q.Clear is a reconstruction algorithm which can overcome the limitation of OSEM(Ordered Subset Expectation Maximization) and reduce the image noise based on voxel unit. The aim of this paper is to evaluate the performance of reconstruction algorithms and optimize the algorithm combination to improve the accurate SUV(Standardized Uptake Value) measurement and lesion detectability. Materials and Methods PET phantom was filled with $^{18}F-FDG$ radioactivity concentration ratio of hot to background was in a ratio of 2:1, 4:1 and 8:1. Scan was performed using the NEMA protocols. Scan data was reconstructed using combination of (1)VPFX(VUE point FX(TOF)), (2)VPHD-S(VUE Point HD+PSF), (3)VPFX-S (TOF+PSF), (4)QCHD-S-400((VUE Point HD+Q.Clear(${\beta}-strength$ 400)+PSF), (5)QCFX-S-400(TOF +Q.Clear(${\beta}-strength$ 400)+PSF), (6)QCHD-S-50(VUE Point HD+Q.Clear(${\beta}-strength$ 50)+PSF) and (7)QCFX-S-50(TOF+Q.Clear(${\beta}-strength$ 50)+PSF). CR(Contrast Recovery) and BV(Background Variability) were compared. Also, SNR(Signal to Noise Ratio) and RC(Recovery Coefficient) of counts and SUV were compared respectively. Results VPFX-S showed the highest CR value in sphere size of 10 and 13 mm, and QCFX-S-50 showed the highest value in spheres greater than 17 mm. In comparison of BV and SNR, QCFX-S-400 and QCHD-S-400 showed good results. The results of SUV measurement were proportional to the H/B ratio. RC for SUV is in inverse proportion to the H/B ratio and QCFX-S-50 showed highest value. In addition, reconstruction algorithm of Q.Clear using 400 of ${\beta}-strength$ showed lower value. Conclusion When higher ${\beta}-strength$ was applied Q.Clear showed better image quality by reducing the noise. On the contrary, lower ${\beta}-strength$ was applied Q.Clear showed that sharpness increase and PVE(Partial Volume Effect) decrease, so it is possible to measure SUV based on high RC comparing to conventional reconstruction conditions. An appropriate choice of these reconstruction algorithm can improve the accuracy and lesion detectability. In this reason, it is necessary to optimize the algorithm parameter according to the purpose.

Lung Cancer Screening with Low-dose Computed Tomography (저선량 CT를 이용한 폐암의 선별 검사)

  • Hwang, Jung Hwa
    • Tuberculosis and Respiratory Diseases
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    • v.57 no.2
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    • pp.118-124
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    • 2004
  • Lung cancer is the leading cause of cancer death for men and women in the industrialized world. It is desirable to detect disease at a stage when it is not causing symptoms and when control or cure is possible. If the screening test detects patients with the disease at an early stage, they can be examined to confirm the diagnosis and intervention can alter the natural history of the disease. The results of screening programs designed to detect early lung cancer using either conventional chest radiograph or sputum cytology are disappointing for a diagnostic screening test. Because of advances in helical CT imaging techniques, screening for lung cancer has been suggested as a possible method of improving outcome. Findings in recent publications suggest that substantial dose reduction is possible in chest CT. The advantages of low-dose CT are more sensitive than chest radiograph for detecting small pulmonary nodules that may be lung cancers, shorter scanning time than conventional chest CT scan without intravenous contrast injection, cheaper cost than standard CT, low radiation dose. However, the true clinical significance of the small tumors found by screening is still unknown, and their effect on mortality awaits future investigation. Furthermore, in addition to detecting an increased number of lung cancers, low-dose CT found at least one indeterminate nodule in many of all screened patients. The majority should be benign but evaluation of all these indeterminate nodules is not a trivial problem in routine practice. In conclusion, lung cancer screening with low-dose CT is a complex subject. The true effectiveness of lung cancer screening (a reduction in mortality from lung cancer) with low-dose CT can be determined through well-designed randomized control trials with enrolment of appropriate subjects.

Effects of Eye Protective Device and Ear Protective Device Application on Sleep Disorder with Coronary Disease Patients in CCU (수면안대와 귀마개 적용이 중환자실 관상동맥질환자의 수면양상에 미치는 효과)

  • Koo, Yoon-Jung;Koh, Hyo-Jung
    • Journal of Korean Academy of Nursing
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    • v.38 no.4
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    • pp.582-592
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    • 2008
  • Purpose: The purpose of this research was to analyze the effects of an eye protective device and ear protective device application on sleep disorder with coronary disease patients in CCU. Methods: The research design was set up as a nonequivalent control group non-synchronized design. The subjects were coronary disease patients in the CCU of a tertiary hospital. The subjects were composed of 20 in the group with an eye protective device, 18 in the group with an ear protective device, 17 in the group with an eye protective device and ear protective device and 20 in the control group. The data was analyzed by $X^2-test$, ANOVA, Repeated measures ANOVA, Sheffe-test, Simple main effect and Time contrast using SPSS Win 12.0. Results: The hypothesis, 'There are significant differences in sleep quantity among the four groups' was supported (F=1,342.71, p=.000). The hypothesis, 'There are significant differences in the subjective evaluation of the general sleep patterns among the four groups' was supported (F=3,638.73, p=.000). In addition the hypothesis, 'There are significant differences in degree of sleep among the four groups' was supported (F=1,616.61, p=.000). Conclusion: It is cost effective and a simple eye protective device and ear protective device should be applied to patients according to their preference and characteristics in the clinical setting.

Effect of Mineral Trioxide Aggregate and Calcium Hydroxide on Reparative Dentin Formation in Rats

  • Ra, Ji-Young;Lee, Wan;Kim, Hyun-Jin
    • International Journal of Oral Biology
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    • v.37 no.2
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    • pp.77-83
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    • 2012
  • We investigated the pulpal response to direct pulp capping in rat molar teeth using mineral trioxide aggregate (MTA) and calcium hydroxide (CH). A palatal cavity was prepared in rat maxillary molar teeth. Either MTA or CH was placed on the exposed pulp and all cavities were restored with composite. Rats were sacrificed for histological evaluation after 12 hours and at 2, 7, 14 and 21 days. In both the MTA and CH groups, reparative dentin formation was clearly observed on histology after 14 days. The MTA-capped pulps were found to be mostly free from inflammation, and hard tissue of a tubular consistent barrier was observed. In contrast, in CH-capped teeth, excessive formation of reparative dentin toward residual pulp was evident. The pulpal cell response beneath the reparative dentin layer was examined by immunofluorescence using antibodies against DSP. After 2 days, a few DSP immunopositive cells, most of which showed a cuboidal shape, appeared beneath the predentin layer. At 7 days, DSP-immunopositive cells with columnar odontoblast-like cells were seen beneath the newly formed hard tissues. At 14 and 21 days, DSP was more abundant in the vicinity of the odontoblastic process along the dentinal tubules than in the mineralized reparative dentin. The CH group showed strong expression patterns in terms of DSP immunoreactivity. Our results thus indicate that MTA may be a more effective pulp capping material as it induces the differentiation of odontoblast-like cells and the formation of reparative dentin without the loss of residual pulp functions.

Behavioral characteristics of phosphorus in sediments according to the forms of phosphorus

  • Kim, Tae-hoon;Lee, Jongjun;Kim, Jungsoo;Oh, Jong-min
    • Journal of Ecology and Environment
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    • v.38 no.3
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    • pp.319-326
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    • 2015
  • This study investigates the behavioral characteristics and forms of phosphorus in the sediment according to the oxygen condition (aerobic/anaerobic). In the behavioral characteristics analysis, Al-P and Fe-P concentrations were the highest among the forms of inorganic phosphorus, and therefore had the strongest impact on sorption and release corresponding to environmental condition changes. In the experimental investigation of the inorganic forms of phosphorus in the sediment according to the oxygen condition, we determined that the forms of inorganic phosphorus did not greatly affect the sorption or release reaction because the distribution ratios of the inorganic forms remained constant corresponding to changes of dissolved oxygen (DO) conditions. In contrast, the forms of organic phosphorus in the sediments affected both sorption and release. Furthermore, labile-P and moderately labile-P forms were the major mechanisms of sorption in sediment. Moderately labile-P was the greatest contributor to phosphorus release action in sediment. As environmental changes are important for the behavioral characteristics of phosphorus in sediment, the forms of phosphorus should be considered to have a greater effect, especially in the organic phosphorus case. Therefore, based on the present study results, sediment evaluation aimed at controlling internal pollutants in reservoirs should include an examination of the forms of phosphorus present, as well as the release characteristics of environmental changes, which are influential factors of phosphorus control. Further research in this field is required.

Study of the Efficacy of Korean Red Ginseng in the Treatment of Androgenic Alopecia (고려 홍삼의 탈모증 개선 효과에 대한 임상 연구)

  • Kim, Jae-Hwan;Yi, Sang-Min;Choi, Jae-Eun;Son, Sang-Wook
    • Journal of Ginseng Research
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    • v.33 no.3
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    • pp.223-228
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    • 2009
  • Alopecia is a common form of hair loss in both male and female, affecting approximately ten million Koreans. Although medical treatments have been developed to treat alopecia, these treatments still have limitations due to complications that come with these treatments. In contrast, Korean red ginseng has been shown to have a stimulating effect on hair follicle and it has already been added to hair treatment products as a safe ingredient. This study was conducted to objectively evaluate the efficacy of Korean red ginseng in the treatment of alopecia. 40 patients suffering from androgenic alopecia were recruited and randomly divided into the experimental (20 patients) and control (20 patients) groups. The experimental group took Korean red ginseng extract (3,000 mg/day) for 24 weeks while the control group took a placebo. The changes of hair counts, thickness, and density were evaluated with Folliscope$^{(R)}$. Patient satisfaction was evaluated through a questionnaire, and clinical photographs were rated by dermatologists. The result of the study showed that Korean red ginseng effectively increased hair density and thickness. Patient satisfaction and evaluation of photographs by dermatologists also confirmed the effectiveness of Korean red ginseng in the treatment of alopecia.

Phenotypic diversity, major genes and production potential of local chickens and guinea fowl in Tamale, northern Ghana

  • Brown, Michael Mensah;Alenyorege, Benjamin;Teye, Gabriel Ayum;Roessler, Regina
    • Asian-Australasian Journal of Animal Sciences
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    • v.30 no.10
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    • pp.1372-1381
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    • 2017
  • Objective: Our study provides information on phenotypes of local chickens and guinea fowl and their body measures as well as on major genes in local chickens in northern Ghana. Methods: Qualitative and morphometric traits were recorded on 788 local chickens and 394 guinea fowl in urban households in Tamale, Ghana. Results: The results showed considerable variation of color traits and numerous major genes in local chickens, while color variations and related genotypes in guinea fowl were limited. In local chickens, white was preferred for plumage, whereas dark colors were preferred for beak and shanks. More than half of the chickens carried at least one major gene, but the contributions of single gene carriers were low. All calculated allele frequencies were significantly lower than their expected Mendelian allele frequencies. We observed higher mean body weight and larger linear body measures in male as compared to female chickens. In female chickens, we detected a small effect of major genes on body weight and chest circumference. In addition, we found some association between feather type and plumage color. In guinea fowl, seven distinct plumage colors were observed, of which pearl grey pied and pearl grey were the most prevalent. Male pearl grey pied guinea fowl were inferior to pearl grey and white guinea fowl in terms of body weight, body length and chest circumference; their shank length was lower than that of pearl grey fowl. Conclusion: Considerable variation in qualitative traits of local chickens may be indicative of genetic diversity within local chicken populations, but major genes were rare. In contrast, phenotypic and genetic diversity in local guinea fowl is limited. Broader genetic diversity studies and evaluation of trait preferences of local poultry producers are required for the design of appropriate breeding programs.

Effect of Mixed Soybeans Materials on Qulity Characteristics of Traditional Soybean Paste(Doenjang) during Aging (혼합콩이 전통된장의 숙성 중 품질에 미치는 영향)

  • Kim, Gwi-Young;Moon, Hye-Kyung;Lee, Su-Won;Moon, Jae-Nam;Yoon, Won-Jung
    • Korean journal of food and cookery science
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    • v.26 no.3
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    • pp.314-322
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    • 2010
  • The effects of five colored soybean (blue, red, yellow, white, and black) varieties on the quality characteristics of soybean paste (Doenjang) were investigated for proximate composition, salt content, pH, color, organic acid content, amino acid content, and mineral content after 80 days of aging. Soybean paste (Doenjang) samples were divided into TDS (traditional Doenjang prepared with soybean) and TDM (traditional Doenjang prepared with mixed soybeans, kidney bean, black soybean, kind of small bean, sword bean, green bean, red bean, at a radio of 1:1:1:1:1(w/w)). Moisture content was 49.66% for TDM and 49.52% for TDM. Protein and salt contents of the TDS sample were higher than those of TDM. The "L" values of the TDB sample increased the aging period was decreased. In contrast, the "L" and "$\alpha$" values of TDM did not show any significant differences. The main organic acids detected were malic acid > lactic acid > tartaric acid in the TDS and TDM samples. Glutamic acid contents were 2.83 g/100 g for the TDS sample and 2.15 g/100 g for the TDM. The levels of K, Mg, and Ca of the TDS sample were higher than those of TDM. No significant difference occurred between TDS and TDM regarding their quality characteristics after 80 days of aging. Further studies needed include sensory evaluation and functionality of soybean paste made from mixed soybean materials.

Epidural Adhesiolysis in Low Back Pain (요통환자에서 경막외 유착 용해술에 의한 제통효과)

  • Lee, Sang-Chul;Oh, Wan-Soo;Kim, Jin-Kyoung;Roh, Chang-Joon;Son, Jong-Chan
    • The Korean Journal of Pain
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    • v.10 no.2
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    • pp.214-219
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    • 1997
  • Background: Epidural neural blockade with local anesthetics combined with steroids has been in clinical trials for patients with low back pain. But pain treatment of low back pain remains somewhat problematic. Many patients with low back pain have epidural fibrosis and adhesions proved with magnetic resonance imaging(MRI) examination. These findings might play an important role in the origin of back pain. Present study was aims to investigate the effect of epidural adhesiolysis in patients with low back pain. Methods: We investigated 76 patients suspected with epidural fibrosis and adhesion was suspected. Nerve pathology was demonstrated and epidural fibrosis suspected or proved with MRI examination. 17G needle specially designed by Racz was inserted at sacral hiatus and catheter was inserted untill its tip was located at lesion site under fluoroscopic guidance. Injection of contrast dye was achieved and prospected spread of agents. Injection of 0.25% bupivacaine, triamcinolone, and 10% hypertonic saline via catheter were carried out daily for 3 days. Evaluation included assessment of pain relief (Numerical Rating Scale; NRS) post-epidural adhesiolysis 3 days, 1 week, and 3 months. We also looked for complication of epidural adhesiolysis. Results: Statistical analysis(Friedman nonparametric repeated measures test and Dune's multiple comparison test) demonstrated NRS was significantly less during 3 months after epidural adhesiolysis(P<0.05). Especially, there is a extremely significance in post-epidural adhesiolysis 3 days (P<0.001). Only four patients reported any complications the most common symptom among three persistent headache but disappeared after a few months without residual sequelae. Conclusion: We conclude epidural adhesiolysis is a safe and effective method of pain therapy for low back pain with proven lumbo-sacral fibrosis and adhesion. A direct visualization by epiduroscopy may be more useful to the resulting functional changes after epidural adhesiolysis.

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The Effects of Habituation and Sensitization on Psychophysiological Differentiation of Responses to Auditory Stimulation with Automobile Horns

  • Estate M. Sokhadze;Sohn, Jin-Hun
    • Science of Emotion and Sensibility
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    • v.3 no.2
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    • pp.17-28
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    • 2000
  • Psychoacoustic characteristics of automobile horns play significant role in resulting subjective evaluation and psychphysiological reactions. However, comparison and differentiation of physiological responses to commercially available horns is a complicated task due to the small contrast in technical features of horns and the influence of such processes as habituation on physiological outcome with the increased number of auditory stimulation trials. In a study on 10 college students, there was performed comparative analysis of reactivity of physiological responses mediated by central and autonomic nervous systems in order to identify the role of habituation on decrement of psychophysiological responsivity and assess the ability to differentiate subjectively most and least preferred, as well as most and least appropriate horns according to physiological manifestations. The EEG and autonomic responses to 7 automobile horns were analyzed during 3 blocks of trials, with varying order of stimuli and changed acoustic parameters of horns in each block. Thus, responses were analyzed for totally 21 trials of auditory stimulation. It was shown that electrodermal and cardiovascular responses have different reactivity patterns to repeated stimulation: skin conductance measures habituated, cardiac reactivity showed no signs of habituation, and the vascular response demonstrated sensitization. The temporal EEG exhibited marked habituation of fast beta band power, while alpha-blocking effect did not habituate during the course of experiment. Differentiation of physiological responses of most and least preferred and appropriate horns was possible in our study, however, some cardiovascular reactivity measures differentiated during the entire course of the experiment, while EEG and electrodermal parameters showed significant differences only during first block of trials, and were later affected by the habituation.

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