• Journal of radiological science and technology
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• v.42 no.4
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• pp.279-284
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• 2019

The purpose of this study was to find the best protocol for balance of image quality and dose in brain CT scan. Images were acquired using dual-source CT and AAPM water phantom, noise and dose were measured, and effective dose was calculated using computer simulation program ALARA(S/W). In order to determine the ratio of image quality and dose by each protocol, FOM (figure of merits) equation with normalized DLP was presented and the result was calculated. judged that the ratio of image quality and dose was excellent when the FOM maximized. Experimental results showed that protocol No. 21(120 kVp, 10 mm, 1.5 pitch) was the best, the organ with the highest effective dose was the brain(33.61 mGy). Among organs with high radiosensitivity, the thyroid gland was 0.78 mGy and breast 0.05 mGy. In conclusion, the optimal parameters and the organ dose in the protocol were also presented from the experiment, It may be helpful to clinicians who want to know the protocol about the optimum state of image quality and dose.

• 대한방사선방어학회:학술대회논문집
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• 2009.04a
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• pp.168-169
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• 2009

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• Toxicological Research
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• v.25 no.3
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• pp.147-157
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• 2009

This study was conducted to obtain acute information of the oral dose toxicity of lyophilized water extract of Pinelliae Rhizoma, a dried tuber of Pinellia ternata (PR) in male and female mice. In order to calculated 50% lethal dose (LD$_{50}$) and approximate lethal dose (ALD), test material was once orally administered to male and female ICR mice at dose levels of 2000, 1000, 500, 250, 125 and 0 (vehicle control) ml/kg (body weight). The mortality and changes in body weight, clinical signs, gross observation, organ weight and histopathology of principle organs were monitored 14 days after treatment with PR extract. We could not find any mortalities, clinical signs, changes in the body and organ weights, gross and histopathological findings except for dose-dependent increases in the hepatic fatty change frequencies detected in PR extract 2000 and 1000mg/kg treated in both male and female mice. The results obtained in this study suggest that LD$_{50}$ and approximate LD in mice after single oral dose of PR extracts were considered over 2000 mg/kg in both and female male mice, but more than 1000mg/kg of PR extracts treatment could induce slight hepatotoxicity the fatty changes in mice.

• Journal of Radiation Protection and Research
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• v.49 no.1
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• pp.1-18
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• 2024

Exponential growth has been observed in nuclear medicine procedures worldwide in the past decades. The considerable increase is attributed to the advance of positron emission tomography and single photon emission computed tomography, as well as the introduction of new radiopharmaceuticals. Although nuclear medicine procedures provide undisputable diagnostic and therapeutic benefits to patients, the substantial increase in radiation exposure to nuclear medicine patients raises concerns about potential adverse health effects and calls for the urgent need to monitor exposure levels. In the current article, model-based internal dosimetry methods were reviewed, focusing on Medical Internal Radiation Dose (MIRD) formalism, biokinetic data, human anatomy models (stylized, voxel, and hybrid computational human phantoms), and energy spectrum data of radionuclides. Key results from many articles on nuclear medicine dosimetry and comparisons of dosimetry quantities based on different types of human anatomy models were summarized. Key characteristics of seven model-based dose calculation tools were tabulated and discussed, including dose quantities, computational human phantoms used for dose calculations, decay data for radionuclides, biokinetic data, and user interface. Lastly, future research needs in nuclear medicine dosimetry were discussed. Model-based internal dosimetry methods were reviewed focusing on MIRD formalism, biokinetic data, human anatomy models, and energy spectrum data of radionuclides. Future research should focus on updating biokinetic data, revising energy transfer quantities for alimentary and gastrointestinal tracts, accounting for body size in nuclear medicine dosimetry, and recalculating dose coefficients based on the latest biokinetic and energy transfer data.

• Proceedings of the Korean Society of Medical Physics Conference
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• 2002.09a
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• pp.206-207
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• 2002

The effective dose due to the X-Ray radiography in the patient positioning for the heavy ion radiotherapy was measured on three regions, chest, upper-abdomen and pelvis. All the radiographic systems and the conditions used in the measurements were same as the clinical trial being performed in National Institute of Radiological Sciences, Japan. The organ or tissue for measurements was selected by following ICRP60$^1$ and the effective dose was calculated from measured organ doses and the surface dose.

• Journal of the Korean Society of Radiology
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• v.7 no.2
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• pp.137-143
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• 2013

This study presents comparison results between axial and spiral scanning in the head and chest region with 64 MDCT to evaluate organ doses in infants and toddlers, who are more radiosensitive to radiation than adults and rise in the number of CT examinations, during CT scanning. Organ doses were significantly lower in spiral scanning than axial scanning regardless of scanned regions. The average organ dose for the chest scan using pitch of 1.355 was found to be significantly higher(average -12.03%) than for the other two pitch settings(0.525 and 0.988) in the spiral scanning mode compared with the axial one. Organ doses in the spiral scanning mode were lower by average 20.54% than the axial scanning mode. The results of the study that evaluated organ doses with an anthropomorphic phantom will help to demonstrate the result values of Monte Carlo simulations and make a contribution to more accurate evaluations of organ doses in toddlers undergoing a CT examination.

• Toxicological Research
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• v.24 no.1
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• pp.79-86
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• 2008

This study was conducted to obtain information of the oral dose toxicity of low molecular fucoidan (LMF) in male and female mice. In order to calculate 50% lethal dose ($LD_{50}$) and approximate lethal dose (LD), test material was once orally administered to male and female ICR mice at dose levels of 2000, 1000, 500, 250, 125 and 0 (vehicle control) mg/kg (body wt.). The mortality and the changes on body weight, clinical signs, gross observation and organ weight and histopathology of principle organs were monitored 14 days after LMF treatment. We could not find any mortalities, clinical signs, body weight changes and gross findings. In addition, significant changes in the organ weight and histopathology of principal organs were not observed except for some sporadic findings. The results obtained in this study suggest that LMF may not be toxic in mice and may be therefore safe for clinical use. The $LD_{50}$ and approximate LD in mice after single oral dose of LMF were considered over 2000 mg/kg in both female and male mice.

• Journal of Physiology & Pathology in Korean Medicine
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• v.28 no.1
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• pp.53-58
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• 2014

The object of this study was to evaluate the single dose toxicity of Choweseuncheng-tang (CWS), a polyherbal formula have been traditionally used as prevention or treatment agent for various diseases as Tae-eumin prescription on Korean medicinal theory, Sasang-euihak, in male and female mice. Aqueous extracts of CWS (yield = 11.00%) was administered to female and male mice as an oral dose of 2,000, 1,000 and 500 mg/kg (body weight) according to the recommendation of Korea Food and Drug Administration (KFDA) Guidelines. Animals were monitored for the mortality and changes in body weight, clinical signs and gross observation during 14 days after dosing, upon necropsy; organ weight and histopathology of 14 principle organs were also examined. As results, we could not find any CWS treatment related mortality and clinical signs, changes in the body and organ weights, gross findings and changes in histopathology of principle organs, except for some dose-independent accidental findings. The results obtained in this study suggest that the 50% lethal dose and approximate lethal dose of CWS aqueous extracts in both female and male mice were considered as over 2,000 mg/kg, the limited highest dosage recommended by KFDA Guidelines, and can be safety used in clinics.

• The Journal of the Korean dental association
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• v.53 no.8
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• pp.558-568
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• 2015

Objective: The objectives of this study were to measure pediatric organ and effective doses of cone-beam computed tomography (CBCT) for orthodontic analysis and to compare them to those of panoramic and lateral cephalometric radiography, the conventional radiography for orthodontic analysis. Materials and Methods: Alphard VEGA for CBCT, Planmeca Proline XC for panoramic radiography and Orthophos CD for cephalometric radiography were used for this study. Thermoluminescent dosimeter (TLD) chips were located at 24 anatomic sites of 10-year-old anthropomorphic phantom and exposed during CBCT (C-mode; $200{\times}179mm$ FOV), panoramic and lateral cephalometric radiographic procedures at the clinical exposure settings for 10-year-old patient. Pediatric organ and effective doses were measured and calculated using ICRP 2007 tissue weighting factors. Results: Effective doses of CBCT, panoramic radiography and lateral cephlometric radiography in pediatric clinical exposure settings were $292.5{\mu}Sv$, $19.3{\mu}Sv$, and $4.4{\mu}Sv$ respectively. The thyroid gland contributed most significantly to the effective dose in all the radiographic procedures. Conclusion: Effective dose of CBCT was about 12 times to conventional radiographic procedures for orthodontic analysis in pediatric patient. The use of CBCT for orthodontic analysis should be fully justified over conventional radiography and dose optimization to decrease thyroid dose is needed in pediatric patients.

• Biomolecules & Therapeutics
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• v.2 no.2
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• pp.161-172
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• 1994

This study was conducted to examine DA-3002, a biosynthetic human growth hormone, for its acute and subacute toxicities in mice and rats. The drug was administered subcutaneously and orally at a dose level of 1.0, 3.0, 8.9, 26.7 or 80.0 lU/kg once for single dose toxicity and given subcutaneously at a dose level of 0.34, 1.7 or 8.4 lU/kg daily for 13 weeks to investigate repeated dose toxicity. In the acute toxicity study, doses up to 80 lU/kg had no adverse effect on the behavior or body weight gain. Pathological examinations revealed no abnormal changes which could be attributed to toxic effect of DA-3002. In the subacute toxicity study, the growth hormone was tolerated well in broth mice and rats. No drug related deaths occurred and all animals appeared to be normal throughout the dosing period. Increases in body weight gain, food utilisation and absolute organ weights were observed in the rats in the high dose group. Mild changes in the blood chemical parameters were also seen in the treated groups. Histopathologically, however, no abnormal changes were observed in any organ. The changes noted during the treatment periods presumably represent exaggerated pharmacological effects of the growth hormone, and no observed adverse effect level (NOAEL) was considered to be more than 8.4 lu/kg/day.