• Title/Summary/Keyword: Radiology science department

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Dose Assessment of Orbital Adnexa in Electron Beam Therapy for Orbital Lymphoma (안와림프종의 전자선 치료 시 안구 부속기관에 대한 선량평가)

  • Dong Hwan Kim;Yong In Cho
    • Journal of the Korean Society of Radiology
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    • v.18 no.3
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    • pp.283-292
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    • 2024
  • Radiation side effects and complications on the ocular adnexa during electron beam therapy for orbital lymphoma can increase the incidence of posterior subcapsular cataracts. This study simulated a medical linear accelerator and a mathematical model of the eye using monte carlo simulations to evaluate the dose to the ocular adnexa and compare the shielding effectiveness on different parts of the ocular adnexa based on lens shield thickness. The dose assessment results of the ocular adnexa showed that the lens's sensitive area had the highest absorbed dose distribution when no shield was used, followed by the lens's non-sensitive area, the anterior chamber, vitreous humor, cornea, and eyelid in descending order. With the use of a shield, a 2 mm thick shield demonstrated a dose reduction effect of over 90% in the lens's sensitive area, over 83% in the non-sensitive area and anterior chamber, and a dose reduction effect of 30 to 62% in the vitreous body, cornea, and eyelid. For dose reduction in the lens's sensitive area during electron beam therapy for orbital lymphoma, it is necessary to use a shield of at least 2 mm thickness. Additionally, shielding strategies considering the thickness and area of the shield for other ocular adnexa besides the lens are required.

Performance Characteristics of MicroPET R4 Scanner for Small Animal Imaging (소동물 영상을 위한 MicroPET R4스캐너의 특성평가)

  • Lee, Byeong-Il;Lee, Jae-Sung;Kim, Jin-Su;Lee, Dong-Soo;Choi, Chang-Un;Lim, Sang-Moo
    • The Korean Journal of Nuclear Medicine
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    • v.39 no.1
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    • pp.49-56
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    • 2005
  • Purpose: Dedicated animal PET is useful equipment for the study of new PET tracer. recently, microPET R4 was installed in the Korea institute of radiology and medical science. In this study, we measured the characteristics of scanner. Materials and methods: Resolution was measured using a line source (F-18:65 ${\mu}Ci$, inner diameter: 0.5 mm). The line source was put in the axial direction and was moved from the center of field of view to outside with 1 mm interval. PET images were reconstructed using a filtered back-protection and ordered subset expectation maximization. line source (16.5 ${\mu}Ci$, 78 mm) was put on the tenter of axial direction to measure the sensitivity when the deadtime was under 1%. Images were acquired during 4 minutes respectively from center to 39 mm outward. Delayed count was subtracted from total count and then decay was corrected for the calculation of sensitivity. Noise equivalent count ratio and scatter fraction were calculated using cylindrical phantom. Results: Spatial resolution of reconstructed image using filtered back-projection was 1.86 mm(radial), 1.95 mm(tangential), 1.95 mm(axial) in the tenter of field of view, and 2.54 mm, 2.8 mm, 1.61 mm in 2 cm away from the center respectively. Sensitivity was 2.36% at the center of transaxial field of view. Scatter fraction was 20%. Maximal noise equivalent count ratio was 66.4 kcps at 242 kBq/mL. Small animal images were acquired for confirmation of performance. Conclusion: Performance characteristics of microPET R4 were similar with reported value. So this will be a useful tool for small animal imaging.

Dental CBCT aided diagnosis of periapical and periodontal lesions (임상가를 위한 특집 3 - CBCT를 이용한 치주-근관 복합병소 진단)

  • Lee, Jae-Seo
    • The Journal of the Korean dental association
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    • v.50 no.4
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    • pp.196-202
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    • 2012
  • Radiographic diagnosis of periapical lesions is based on many factors, including anatomical limitations such as thickness of the cortical bone; positioning of the apical abscess to the cortical bone; and is complicated by proximity to other anatomical structures and neighboring teeth. With conventional radiographs, these structures are often superimposed. Dental CBCT with its associated geometric accuracy offers accurate visualizations of the complex relationships and boundaries between teeth, related anatomical features, and their associated pathology. Its images also provide us internal tooth morphology, periodontal ligament space, the presence or absence of periapicl lesions in association wi th critical anatomical structures and maxillary sinus involement. Using 3 D imaging makes it easier for clinicians to detect, diagnosis, and develop highly effective treatment plans. Now, 4 cases of periapical and periodontal pathosis with CBCT images are to be presented including periapical abscess, furcation involvement, periapical pathosis involving maxillary sinus, and osteomyelitis. CBCT analyze specific area of interest and provides the highly detailed anatomical information. It also facilitates earlier and more accurate diagnosis, and treatment planning decisions and more predictable outcome.

Estrus Behavior and Superovulatory Response in Black Bengal Goats (Capra hircus) Following Administration of Prostaglandin and Gonadotropins

  • Mishra, O.P.;Gawande, P.G.;Nema, R.K.;Tiwari, S.K.
    • Asian-Australasian Journal of Animal Sciences
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    • v.17 no.10
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    • pp.1374-1377
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    • 2004
  • The present study was conducted to explore the possibilities of estrus induction and superovulation in a native Indian breed of goats called 'Black Bengal'. Forty-two adult non-pregnant females were divided in two groups, of which 18 goats were subjected to a superovulatory treatment comprising of equine chorionic gonadotropin (eCG), Prostaglandin (PGF2$\alpha$) and human chorionic gonadotropin (hCG) to induce superovulation. The remaining 24 goats received no treatment and served as controls for the parameter under study as well as recipients for embryo transfer studies. The average duration of estrus was found to be significantly increased in treated goats (34.2${\pm}$3.4 h) compared to controls 3.0${\pm}$2.4 h). The average duration between PGF administration and occurrence of estrus was 2.0${\pm}$5.2 h. After mid ventral laparotomy, superovulatory responses indicated a significant increase in the number of follicles, which was 8.27${\pm}$0.37 in the treatment group compared to 4.16${\pm}$0.17 in the control group. The number of corpora lutea was also significantly increased in treated animals compared to control (2.90${\pm}$0.86 vs. 0.74${\pm}$0.04) respectively per ovary per goat.

Pharyngeal airway dimensions in skeletal class II: A cephalometric growth study

  • Uslu-Akcam, Ozge
    • Imaging Science in Dentistry
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    • v.47 no.1
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    • pp.1-9
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    • 2017
  • Purpose: This retrospective study aimed to evaluate the nasopharyngeal and oropharyngeal dimensions of individuals with skeletal class II, division 1 and division 2 patterns during the pre-peak, peak, and post-peak growth periods for comparison with a skeletal class I control group. Materials and Methods: Totally 124 lateral cephalograms (47 for skeletal class I; 45 for skeletal class II, division 1; and 32 for skeletal class II, division 2) in pre-peak, peak, and post-peak growth periods were selected from the department archives. Thirteen landmarks, 4 angular and 4 linear measurements, and 4 proportional calculations were obtained. The ANOVA and Duncan test were applied to compare the differences among the study groups during the growth periods. Results: Statistically significant differences were found between the skeletal class II, division 2 group and other groups for the gonion-gnathion/sella-nasion angle. The sella-nasion-B-point angle was different among the groups, while the A-point-nasion-B-point angle was significantly different for all 3 groups. The nasopharyngeal airway space showed a statistically significant difference among the groups throughout the growth periods. The interaction among the growth periods and study groups was statistically significant regarding the upper oropharyngeal airway space measurement. The lower oropharyngeal airway space measurement showed a statistically significant difference among the groups, with the smallest dimension observed in the skeletal class II, division 2 group. Conclusion: The naso-oropharyngeal airway dimensions showed a statistically significant difference among the class II, division 1; class II, division 2; and class I groups during different growth periods.

Impact of radiotherapy on mandibular bone: A retrospective study of digital panoramic radiographs

  • Palma, Luiz Felipe;Tateno, Ricardo Yudi;Remondes, Cintia Maria;Marcucci, Marcelo;Cortes, Arthur Rodriguez Gonzalez
    • Imaging Science in Dentistry
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    • v.50 no.1
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    • pp.31-36
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    • 2020
  • Purpose: The purpose of this study was to investigate the impact of radiotherapy on mandibular bone tissue in head and neck cancer patients through an analysis of pixel intensity and fractal dimension values on digital panoramic radiographs. Materials and Methods: Thirty patients with radiographic records from before and after 3-dimensional (3D) conformational radiotherapy were selected. A single examiner carried out digital analyses of pixel intensity values and fractal dimensions, with the areas of interest unilaterally located in the right angle medullary region of the mandible below the mandibular canal and posterior to the molar region. Results: Statistically significant decreases were observed in the mean pixel intensity (P=0.0368) and fractal dimension (P=0.0495) values after radiotherapy. Conclusion: The results suggest that 3D conformational radiotherapy for head and neck cancer negatively affected the trabecular microarchitecture and mandibular bone mass.

Development of a Program for Anger Management Based on Self-efficacy in Patients with Breast Cancer (유방암 환자의 분노관리 자기효능감 증진 프로그램 개발)

  • Oh, Pok-Ja;Choi, Seung-Yi
    • Korean Journal of Adult Nursing
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    • v.21 no.2
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    • pp.199-211
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    • 2009
  • Purpose: The purpose of this study was to develop a program for anger management based on self-efficacy. Methods: In this study, four types of approaches to enhance anger control were developed; 1) a role play for vicarious experiences; 2) an assertive training for anger expression; 3) a 30-minute long education program & a 20-minute long telephone call coaching for verbal persuasion; and 4) a booklet for anger management and self care behaviors. One group pretest-posttest design was used for evaluating the program. Study subjects were 6 cancer patients undergoing chemotherapy. The group were received a 4-week intervention, 60 ~ 90 minutes a day weekly, and measured the variables at baseline, 4 weeks later. Anger-in, anger-out, and anger-control were measured by STAXI-K. Data was analysed by Wilcoxon using SPSS/WIN 12.0 program. Anger situation was analysed according to primary anger-thoughts and secondary anger-thoughts based on cognitive theories of anger. Results: The program for anger management consisted of a role play, assertive training, education, telephone call coaching and a booklet. The program revealed significantly less Anger-in (Z = -1.997, p = .046), anger-out (Z = -2.207, p = .027). No difference, however, was found in anger control (Z= -1.826, p=.068). Conclusion: This evaluation suggested that more assertive training and longer intervention may be needed to maximize anger control.

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Effect of water extract of Danshen on bone regeneration of rat calvarial defect model (랫드 두개골 결손부에서 단삼 수용성 추출물의 골형성 효과)

  • Shim, Kyung Mi;Kim, Se Eun;Kang, Seong Soo
    • Korean Journal of Veterinary Research
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    • v.50 no.3
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    • pp.171-177
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    • 2010
  • The purpose of this study was to evaluate the osteogenic capacity of water extract of danshen (Salvia miltiorrhiza Bunge). We have established in rat critical-sized calvarial defect model using the combination with collagen scaffold and danshen hydrophilic extract. All rats were extinguished at 8 weeks after bone graft surgery, and the bone regeneration ability of bone grafting sides was evaluated by plain radiography and micro-CT. These results revealed water extract of danshen had the potential to promote osteogenesis especially continuous oral administration with local treatment compared to one-shot local treatment. This compound may provide a new alternative agent for growth factors to promote bone healing and bone regeneration. In conclusion, these results suggest that danshen hydrophilic extract have the potential to promote osteogenesis in bone defects. Further studies about fusion technology with salvianolic acid B, peptides, growth factors, and scaffolds using of the combination of tissue engineering, cell engineering and mechanical engineering are needed.

Dental maturity of Saudi children: Role of ethnicity in age determination

  • Baghdadi, Ziad D.
    • Imaging Science in Dentistry
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    • v.43 no.4
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    • pp.267-272
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    • 2013
  • Purpose: Demirjian's dental maturity scores and curves have been widely used for human age determination. Several authors have reported considerable differences between the true and estimated age based on the Demirjian curves, which have been accounted for by ethnicity. The purpose of the current study was to assess the role of ethnicity-specific dental maturation curves in age estimation of Saudi children. Materials and Methods: A sample of 452 healthy Saudi children aged 4 to 14 years were aged based on the original French-Canadian Demirjian curves and several modified Demirjian curves specified for certain ethnic groups: Saudi, Kuwaiti, Polish, Dutch, Pakistani, and Belgian. One-way ANOVA and a post hoc Scheff$\acute{e}$'s test were used to assess the differences between chronological age and dental age estimated by the different curves (P<0.05). Results: The curves designed for Dutch, Polish, Saudi, and Belgian (5th percentile) populations had a significantly lower error in estimating age than the original French-Canadian and Belgian (50th percentile) curves. The optimal curve for males was the Saudi one, with a mean absolute difference between estimated age and chronological age of 8.6 months. For females, the optimal curve was the Polish one, with a mean absolute difference of 7.4 months. It was revealed that accurate age determination was not related to certain ethnicity-specific curves. Conclusion: We conclude that ethnicity might play a role in age determination, but not a principal one.

A Study on the Difference Method of Magnetic Resonance Signal Measurement when Using Multi-channel Coil and Parallel Imaging

  • Choi, Kwan-Woo;Lee, Ho-Beom;Son, Soon-Yong;Jeong, Mi-Ae
    • Journal of Magnetics
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    • v.22 no.2
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    • pp.220-226
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    • 2017
  • SNR (signal to ratio) is a criterion for providing objective information for evaluating the performance of a magnetic resonance imaging device, and is an important measurement standard for evaluating the quality of MR (Magnetic Resonance) image. The purpose of our study is to evaluate the correct SNR measurement for multi-channel coil and parallel imaging. As a result of research, we found that both T1 and T2 weighted images show the narrowest confidence interval of the method recommended by NEMA (The National Electrical manufacturers Association) 1 having a single measurement method, whereas the ACR (American College of Radiology) measurement method using a multi-channel coil and a parallel imaging technique shows the widest confidence interval. There is a significance in that we quantitatively verified the inaccurate problems of a signal to noise ratio using a ACR measurement method when using a multi-channel coil and a parallel imaging technique of which method does not satisfy the preconditions that researchers could overlook.