• The Korean Journal of Nuclear Medicine Technology
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• v.18 no.1
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• pp.82-88
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• 2014

Purpose: The purpose of study was to evaluate radiation dose for pediatric patients by changing tube voltage (kVp) and tube current (mA) at minimum conditions. By evaluating radiation dose, we want to provide dose reduction for pediatric patients and maintain good quality of SPECT/CT images. Materials and Methods: Discovery NM/CT 670 Scanne was used as SPECT/CT. Tube voltages are 80 and 100 kvP. Tube currents are 10, 15, 20, 25 mA. Using PMMA (Polymethyl methacrylate) Phantom, radiation dose which were calculated at center and peripheral dose and SNRD (Signal to Noise Ratio Dose) were evaluated. Using the CT performance phantom, spatial resolution was evaluated as the MTF (Modulation Transfer Function) graph. Jaszczak phantom was used for SPECT image evaluation by CNR (Contrast to Noise to Ratio). Results: Radiation dose using the PMMA phantom was higher peripheral dose than center dose about 7%. SNRD were 7.8, 8.2, 8.3, 8.8, 8.8, 9.9, 9.8, 9.6 for 80 kVp 10, 15, 20, 25 mA, 100 kVp 10, 15, 20, 25 mA. We can distinguish 35, 45, 70, 71, 52, 58, 90, 110 linepair for 80 kVp 10, 15, 20, 25 mA, 100 kVp 10, 15, 20, 25 mA at resolution with MTF. CNR of SPECT images using CT attenuation map were 57.8, 57.7, 57.1, 56.7, 56.6, 56.7, 56.7, 56.7% for 80 kVp 10, 15, 20, 25 mA, 100 kVp 10, 15, 20, 25 mA. Conclusion: In this study, radiation dose for pediatric patients showed decreased low dose condition. And SNRD value was similar in all condition. Resolution showed higher value at 100kVp than 80kVp. for CNR, there was no significant difference. we should take additional study to prove better quality and dose reduction.

• Archives of Obesity and Metabolism
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• v.3 no.1
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• pp.43-48
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• 2024

Idiopathic intracranial hypertension (IIH) is characterized by increased intracranial pressure without detectable causes. Its main symptoms include headache, vision problems, and pulsatile tinnitus. Obesity is a major risk factor for IIH; therefore, weight reduction is required to ameliorate these symptoms in patients with obesity and IIH. We present four cases of obesity-related IIH whose symptoms improved through weight reduction. In three patients, the dose of IIH medications, such as acetazolamide, decreased. Based on these cases, we report that weight reduction contributes to the improvement of symptoms in patients with IIH as the main part of treatment. Further clinical research is necessary to evaluate the effects of weight reduction on IIH treatment in Korean patients.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.41 no.3
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• pp.348-353
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• 1996

Mutation tachniques inducing more useful mutations and reducing somatic effects need to be improved for crop breeding. Seeds of barley varieties ; Dema, Grosso were treated with two types of mutagens ; 1) chemical treatment: single treatment or double treatment of two mutagens (N-nitroso-N-methylurea ; MNH, Sodium Azide; NaN$_3$) 2) gamma ray irradiation treatment. After treatment, half of seeds were used for germination test and half of seeds were sown to the field. With the higher dose of mutagen both chemical and gamma ray were plants treated, the higher rate of growth reduction rate was in M$_1$ seedling. In chemical treatment, germination rate of seeds, growth rate of coleoptile and root in double treatment of chemical mutagens were better than single treatments, especially in same dose. Growth inhibition rate of plant in double treatment of 1.0mM MNH(0.5mM MNH + 0.5mM MNH), for example, were less than one of plants of single treatment of 1.0mM MNH in pot and petri dish test. Growth reduction rate of culm and fertility rate in M$_1$ plants double treated in same dose of single treatment were also less than single one. With the higher dose of mutagen both chemical and gamma ray were plants treated, the higher frequency of chlorophyll mutants was in M$_2$ seedling. The rate of chlorophyll mutants in double treatment of chemical mutagens were higher than single treatment. Double treatment methods can be a improved method for induction of new good mutants, which were induced more useful mutations and reduced harmful somatic effects.

• Journal of the Korean Society of Radiology
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• v.16 no.1
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• pp.7-13
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• 2022

This study compared the aortic root image by using the ECG gating and non-ECG gating methods. We observed the presence or absence of progression of the aortic root image in the images examined by the high pitch (flash) chest pain protocol method and in the patients tested without ECG gating by the conventional method. The AAPM phantom was scanned by using high pitch (flash) chest pain protocol and general chest pain protocol. CTDI values were compared. By ECG gating, the blurring of ascending aorta was significantly reduced compared to the existing non-ECG gating test method, and the image quality of the aortic root was improved. Within the parametar range that did not show differences in noise, uniformity, and high contrast resolution, CTDI values were lower when tested with the high-pitch chest pain protocol. It was found that there is an advantage in dose reduction, and if it is applied and applied to diagnostic fields such as dissection using the dose reduction mode in the cardiac field, it is a very important test for patients who need rapid diagnosis and prompt treatment as well as a dramatic reduction in exposure dose. It is presumed to be a method.

• Childhood Kidney Diseases
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• v.21 no.1
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• pp.35-39
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• 2017

Azathioprine is commonly used as immunosuppressive therapy for various inflammatory diseases including chronic glomerulonephritis. Myelosuppression is a common side effect of azathioprine, resulting in the need for dose reduction. However, severe pancytopenia or alopecia is not often encountered. Here, we report a case of severe myelosuppression, and alopecia totalis that occurred after azathioprine treatment in a patient with IgA nephropathy. A 10-year-old boy with IgA nephropathy was treated with oral deflazacort and later with azathioprine. After 4 weeks, the patient complained of hair loss, and despite a dose reduction in azathioprine, he developed bone marrow suppression and alopecia totalis in two weeks. The blood indices and alopecia of the patient had returned to normal after azathioprine withdrawal and 3 consecutive doses of granulocyte colony-stimulating factor. We suggest that physicians remain vigilant to the side effects of azathioprine. Unusual hair loss after azathioprine treatment might suggest a defect in the metabolism of the drug, warranting the discontinuation of azathioprine to prevent more severe side effects.

• Journal of Korean Society on Water Environment
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• v.26 no.6
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• pp.948-953
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• 2010

In this study, degradation of estrone (E1) and $17{\alpha}$-ethynylestradiol (EE2) by gamma-irradiation and subsequent reduction of estrogenic activity as a function of absorbed dose were conducted using the yeast two-hybrid assay. Relative potency of E1 and EE2 compared to estrogenic activity of $17{\beta}$-estradiol (E2) was found to be 0.0144 and 0.1605, respectively. More than 90% of E1 and EE2 (both $5.0{\times}10^{-6}M$) was removed at an absorbed dose of 5 kGy, but more than 40% of estrogenic activity still remained. The addition of $TiO_2$ catalyst appeared to improve the removal efficiency of E1 and decrease estrogenic activity while there was no significant effect for EE2. Additionally, the calculated estrogenic activity of E1 and EE2 based on a regression model was well correlated with the observed activity.

• The Korean Journal of Pain
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• v.24 no.1
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• pp.22-30
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• 2011

Background: Pregabalin has been shown to have analgesic effect in acute pain models. The primary objective was to examine the efficacy a single dose of pregabalin, would have on morphine consumption following lumbar discectomy. Methods: With ethical approval a randomized, placebo-controlled prospective trial was undertaken in 32 patients (ASA I-II, 18-65 years) with radicular low back pain for > 3 months undergoing elective lumbar discectomy. Patients received either oral pregabalin 300 mg (PG Group) or placebo (C Group) one hour before surgery. Pain intensity, the accumulative morphine consumption and adverse effects were recorded for 24 hours following surgery. Functional, psychological and quantitative sensory testing were also assessed. Results: Fourteen patients out of the 32 recruited were randomized to receive pregabalin. Morphine consumption was reduced (absolute difference of 42.3%) between groups with medium effect size. (Mann-Whitney; U =52.5, z-score= 2.84, P = 0.004, r = 0.14). This was not associated with a significant difference in the incidence of adverse effects between the two groups. The median pain intensity (VAS) on movement was not significantly different between groups. Conclusions: A single pre-operative dose of pregabalin (300 mg) did not result in a reduction in pain intensity compared to placebo in this patient cohort but the significant reduction in morphine consumption suggests that a fixed peri-operative dosing regime warrants investigation.

• International Journal of Oral Biology
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• v.43 no.4
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• pp.185-191
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• 2018

Alcohol intake is known to affect various organs in the human body, causing reduction of salivation in the oral cavity. Hypo-salivation effect of alcohol is a common feature, but the mechanism in salivary glands is still poorly studied. Therefore, in this study, the changes in salivary secretion and water channel protein (aquaporin5, AQP5) in salivary glands of mice were investigated after ethanol administration. Animals were divided in to 4 groups with the control, 4 g/kg ethanol, 8 g/kg ethanol and 16 g/kg ethanol administration groups. One hour after ethanol administration, saliva was collected from the oral cavity, and the animals were killed and parotid and submandibular glands were extracted to analyze the histopathology, AQP5 immunihistochemistry and AQP5 protein level. According to the results, the salivation rate decreased irrespective of the ethanol dose in mice, and viscosities increased with increase in ethanol dose. However, there were no pathological changes in parotid and submandibular glands due to ethanol administration. Expression of AQP5 in parotid and submandibular glands decreased with increase ethanol administration These results indicate that the reduction of salivary secretion due to acute alcohol intake is closely related to decrease of the water channel protein such as AQP5 in parotid glands and submandibular glands, rather than the damage of salivary glands.

• Journal of the Korean Society of Radiology
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• v.83 no.3
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• pp.669-679
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• 2022

Purpose To evaluate the feasibility of pediatric low-dose facial CT reconstructed with filtered back projection (FBP) using adequate kernels. Materials and Methods We retrospectively reviewed the clinical and imaging data of children aged < 10 years who underwent facial CT at our emergency department. The patients were divided into two groups: low-dose CT (LDCT; Group A, n = 73) with a fixed 80-kVp tube potential and automatic tube current modulation (ATCM) and standard-dose CT (SDCT; Group B, n = 40) with a fixed 120-kVp tube potential and ATCM. All images were reconstructed with FBP using bone and soft tissue kernels in Group A and only bone kernel in Group B. The groups were compared in terms of image noise, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR). Two radiologists subjectively scored the overall image quality of bony and soft tissue structures. The CT dose index volume and dose-length product were recorded. Results Image noise was higher in Group A than in Group B in bone kernel images (p < 0.001). Group A using a soft tissue kernel showed the highest SNR and CNR for all soft tissue structures (all p < 0.001). In the qualitative analysis of bony structures, Group A scores were found to be similar to or higher than Group B scores on comparing bone kernel images. In the qualitative analysis of soft tissue structures, there was no significant difference between Group A using a soft tissue kernel and Group B using a bone kernel with a soft tissue window setting (p > 0.05). Group A showed a 76.9% reduction in radiation dose compared to Group B (3.2 ± 0.2 mGy vs. 13.9 ± 1.5 mGy; p < 0.001). Conclusion The addition of a soft tissue kernel image to conventional CT reconstructed with FBP enables the use of pediatric low-dose facial CT protocol while maintaining image quality.

• Korean Journal of Digital Imaging in Medicine
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• v.15 no.2
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• pp.13-18
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• 2013

Purpose : Fluoroscopy equipment, depending on the type of changes that occur in the patient's position ESD and study the patient's scatter ray of ESD Practitioners considered a comparative analysis was to evaluate the correct dose. Materials and Methods : HITACHI four overtube type TU-8000 Flat Detector and Under tube C-Arm Philips' Multi Diagnost Eleva with Flat Detector type were measured by. Each devices is a measure of the patient's esd randophantom position in tabel unfors Xi multi funtion then fixed to the abdomen fluoroscopy and 10 seconds, spot was measured three times, practitioners of the incident surface dose by considering the patient's scatter ray of the table for each device in the average human stomach 21cm thickness acrylic phantom ($25cm{\times}25cm$) Place the practitioner position after position randophantom unfors Xi multi funtion in the thyroid and stomach 1 minute by a fixed one-time fluoroscopy and measured. Results : 10 seconds and the patient perspective of the c-arm ESD 1.2 times smaller on the AP and oblique measurements were measured in the 6-13 times smaller. spot positions to changes in the measured three times on the AP of the abdomen, ESD is 18 times smaller c-arm measurements and the oblique measurement was 19-30 times smaller. And 1 minute at practitioners fluoroscopy esd in the thyroid 2.12 times the c-arm, chest 1.75 times less the dose was measured. On the AP, depending on the device, but the lack of dose difference oblique positions of the two devices depending on changes in the area due to changes in both the AP than on the dose increased, the difference in dose between the two devices, the maximum difference was approximately 27 times. Conclusion : Fluoroscopic equipment at the time of inspection in accordance with changes in dose according to the patient and the patient's positions changes, because the area of the scatter ray considering the change of dose measurements be made, and study of the equipment according to the characteristics of the efficiency and the exposure of the patient and practitioner is considered smooth study equipment manufacturers that can be done is to build the system and think that is also important. Various fluoroscopy when you check future changes in many factors of change in dose for the equipment in the laboratory system by considering the scatter ray radiation shielding for the management to take advantage of reckless undertube have been utilized as more exposure Reduction activities can help is considered as the direction.