• Journal of the Korean Society of Radiology
• /
• v.9 no.5
• /
• pp.279-285
• /
• 2015

The eye of human is a radiation sensitive organ and this organ should be shielded from radiation exposure during brain CT procedures. In the brain CT procedures, bismuth protector using to reduce the radiation exposure dose for eye. But protecting the bismuth always accompanies problem of the image quality reduction including artifact. This study aim is the eye radiation exposure dose and image quality evaluation of the new tube current modulation such as new organ based-tube current modulation, longitudinal-TCM, angular-TCM between shielding scan technique using bismuth and lead glasses. As a result, radiation dose of eye is reduced 25.88% in new OB TCM technique then reference scan technique and SNR new OB TCM is 6.05 higher than bismuth shielding scan technique and lower than reference scan technique. In clinical brain CT, new OB TCM technique will contribute to reduction of radiation dose for eye without decrease of image quality.

• Journal of the Korean Society of Radiology
• /
• v.8 no.4
• /
• pp.147-153
• /
• 2014

We tried to assessment about characteristics of image through quantitative evaluation method and qualitative evaluation method in Full Field Digital Mammography. It satisfied an approval standard of ten score regardless of compression ratio measuring detection score after compressing and appling an algorithm of JPEG2000 orJPEG compression targeting ACR accreditation phantom. Also, it was apparent that when we selected and compressed the image of real fine lesion and measured a change of diagnosis ability magnifing over 50 percent after compressing over 20:1 ratio, it had a strong influence on diagnosis ability. We realized that the difference between the original image according to compression ratio measuring a quantitative evaluation which is PSNR,RMSE,MAE and SSIM was relatively allowable.

• Journal of the Korean Society of Radiology
• /
• v.13 no.4
• /
• pp.667-674
• /
• 2019

Because examination with technegas produces images through simple diffusion accumulation, the examination room can become contaminated after scan. Therefore, radiation workers and patients awaiting examination will be affected by internal exposure from technegas inhalation. Before and after gravity ventilation, I am trying to find a way to reduce the exposure dose of waiting patients according to a comparative analysis of horizontal spatial dose rates over time. Spatial dose ratio were measured for 10 minutes from various distances and angles around ventilator's location before and after gravity ventilation. Then, mean values, standard deviation and reduction ratio were calculated. The highest reduction rate of gravity ventilation was 95.31% and the highest reduction ratio was 1 to 3 minutes. Therefore, the gravity ventilation could reduce the exposure dose of radiologic technologists, waiting patients, patient guardians and nurses. In conclusion, the reduction of the exposure dose during the technegas ventilation study through gravity ventilation will play a role in optimiging the protection and it is in accordance with the recommended reduction of the medical exposure by ICRP 103.

• Journal of radiological science and technology
• /
• v.31 no.1
• /
• pp.71-81
• /
• 2008

Our objective was to evaluate the image of spatial domain filtering as an alternative to additional image reconstruction using different kernels in MDCT. Derived from thin collimated source images were generated using water phantom and abdomen B10(very smooth), B20(smooth), B30(medium smooth), B40 (medium), B50(medium sharp), B60(sharp), B70(very sharp) and B80(ultra sharp) kernels. MTF and spatial resolution measured with various convolution kernels. Quantitative CT attenuation coefficient and noise measurements provided comparable HU(Hounsfield) units in this respect. CT attenuation coefficient(mean HU) values in the water were values in the water were $1.1{\sim}1.8\;HU$, air($-998{\sim}-1000\;HU$) and noise in the water($5.4{\sim}44.8\;HU$), air($3.6{\sim}31.4\;HU$). In the abdominal fat a CT attenuation coefficient($-2.2{\sim}0.8\;HU$) and noise($10.1{\sim}82.4\;HU$) was measured. In the abdominal was CT attenuation coefficient($53.3{\sim}54.3\;HU$) and noise($10.4{\sim}70.7\;HU$) in the muscle and in the liver parenchyma of CT attenuation coefficient($60.4{\sim}62.2\;HU$) and noise ($7.6{\sim}63.8\;HU$) in the liver parenchyma. Image reconstructed with a convolution kernel led to an increase in noise, whereas the results for CT attenuation coefficient were comparable. Image scanned with a high convolution kernel(B80) led to an increase in noise, whereas the results for CT attenuation coefficient were comparable. Image medications of image sharpness and noise eliminate the need for reconstruction using different kernels in the future. Adjusting CT various kernels, which should be adjusted to take into account the kernels of the CT undergoing the examination, may control CT images increase the diagnostic accuracy.

• Journal of Dental Rehabilitation and Applied Science
• /
• v.30 no.1
• /
• pp.28-35
• /
• 2014

Osteochondroma is the most common benign bone tumor. The majority of osteochondromas (85%) present as solitary, nonhereditary lesions. In general, osteochondroma has no symptoms,however, facial asymmetry, malocclusion, crossbite and mouth opening can be occurred in case of temporomandibular joint involved. Radiologic analyses are indispensable element to diagnose osteochondroma and pathogenetic analysis showed that hereditary multiple osteochondromas are caused by mutations in either of two genes: exostosis(multiple)-1 (EXT1), which is located on chromosome 8q24.11 - q24.13 or exostosis(multiple)-2 (EXT2), which is located on chromosome 11p11 - 12. Recently, reduced mRNA of EXT1 was described in nonhereditary osteochondromas. The treatment of choice for osteochondroma is surgical unless the skeleton is still immature. Surgery associated with orthodontic treatment can be a valid approach to minimize facial asymmetry and malocclusion in case of temporomandibular with osteochondroma.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.14 no.4
• /
• pp.1871-1876
• /
• 2013

In this study, we developed and characterized the shielding properties of dose reduction fiber (DRF, Buffalo Co.) sheet during brain and chest CT examinations. The DRF sheet was composed of $1{\sim}500{\mu}m$ oxide Bismuth ($Bi_2O_3$) and 5 ~ 50 nm nano-barium sulfate ($BaSO_4$). Phantom and clinical studies were performed for characterization of the DRF shielding properties. In clinical study, we measured doses of eye, chest, abdomen and reproductive system of 60 patients in 3 hospitals during brain and chest CT examinations. We could determined the shielding effect of the DRF by comparing the doses when we used the DRF sheet or not. When we used the sheet during CT examination, the scattered dose were reduced about 20~50%. So, we suggest that the fiber should be used in radiological examinations for reducing patients doses.

• Journal of the Korean Society of Radiology
• /
• v.17 no.5
• /
• pp.775-782
• /
• 2023

In order to overcome practical limitations in installing, managing and operating MRI machines with expensive equipment, this study developed and utilized virtual reality (VR) experience education by combining virtual reality (VR) with magnetic resonance imaging devices. The Students who experienced virtual reality-based educational systems were surveyed to identify possible side effects during the experience and self-directed learning ability and academic self-efficacy surveys were conducted to analyze the impact of virtual reality-based practice on learning. In the analysis of the self-directed learning ability survey there was no difference in the average between the student group who experienced education and the student group who did not but there was a significant difference in the average for each group. Virtual Reality-based practical education is expected to provide an efficient practice system by providing new learning methods and opportunities for education that can be repeated anytime, anywhere regardless of time and space.

• The Korean Journal of Emergency Medical Services
• /
• v.22 no.3
• /
• pp.7-34
• /
• 2018

Purpose: The purposes of this research were to study the validity of the National Examination based on smart based test(SBT) by 7 types of healthcare occupation. Methods: We conducted a questionnaires survey among 1,219 people including 210 professors for all 7 types of healthcare occupation and 573 clinical specialists ; 436 students from random sampling participated and the reliability of the questionnaire was tested using Cronbach's alpha. Results: Professors from 7 types of healthcare occupation were investigated for their opinions on the introduction of the SBT system ; 65.9% of the professors answered positively on the introduction of the SBT National Examination System, while 40.1% of the clinical experts answered likewise. In particular, professors and the clinical experts recognized altogether that the multimedia questionnaire, being effective for the evaluation of clinical and practical competence of the subjects, enabling the evaluation of various areas and strengthening the school education in clinical practices, the 42.0% of the students from 7 departments answered that the future direction of the national test is in the SBT test system with significant difference (p=.000) found in students majoring in order of Emergency Medical Services, Radiology and Physical therapy, compared to students from other majors, showing the positive response to the SBT system. Conclusion: The results of this study comprehensively evaluated the positive recognition of development of multimedia items and SBT system in national examination of 7 types of healthcare occupation in professors, field specialists and students.

• Journal of radiological science and technology
• /
• v.32 no.4
• /
• pp.411-418
• /
• 2009

To evaluate the bone mineral density (BMD) and biochemical markers. We evaluated the BMD of femoral neck and lumbar spines of 998(male 568, female 430) persons who took a regular health screening in Woosuk University Hospital from September 2007 to March 2008 by dual energy bone mineral densitometry. Results of BMD are different in terms of biochemical markers. Especially aged people showed osteoporotic change progressively. Degree of osteoporosis increases with age. A steep decrease of BMD can be found in postmenopausal women who have low level of female hormone. More persistent effort is needed to find out the factors that can reduce BMD values for prevention of problems by osteoporosis. In essence, research on factors related to other biochemical markers must be studied continuously.

• Journal of Sensor Science and Technology
• /
• v.12 no.1
• /
• pp.16-23
• /
• 2003

Thermoluminescent properties of $Li_2B_4O_7$ single crystal grown by Czochralski method have been investigated. The high quality $Li_2B_4O_7$ single crystal without core was obtained at rotation speed of 10 rpm for seed crystal and pulling speed below $0.18\;mm{\cdot}h^{-1}$. The structure of $Li_2B_4O_7$ single crystal was classified as tetragonal by XRD analysis. The TL glow curve was composed with three overlapped peaks which can be easily deconvoluted and the TL response of $Li_2B_4O_7$ single crystal TLD to X-ray radiation is linear within the range of $50\;mGy{\sim}1.5\;Gy$. Activation energies of three TL glow peaks analyzed by the various heating rates method and PL spectrum were 0.93, 1.78 and 2.25 eV, respectively.