• Journal of radiological science and technology
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• v.44 no.6
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• pp.607-613
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• 2021

Long-bone examination is mainly used for inspection of the lower extremities. Recently, a long length detector (FXRD-1751S, VIEWORKS, Korea) with three digital detectors attached has been developed. High energy X-rays are used because pelvic areas require high image quality. In this case, X-rays are transmitted a lot in thin areas such as an ankle, and it is not suitable for diagnosing an image. Therefore, this study use copper filters made with 3D printers to increase image quality in the Long-bone inspection. A copper filter was manufactured in consideration of the overall thickness of the lower part. The experiment was conducted in anterior-posterior (AP) and lateral (LAT) positions, depending on the presence or absence of the filter. 5x5 pixels of region of interest (ROI) were selected from the pelvis, knee, and ankle areas. X-rays were irradiated under the conditions of 70 kVp and 40 mAs for AP, 80 kVp, and 63 mAs for lat when without filters, 90 kVp and 80 mAs for AP, 90 kVp and 100 mAs for lat when with filters. signal to noise ratio(SNR) ratio and contrast to noise (CNR) values were measured 1106.38, 14.34 before applying the filter and 1189.32, 70.43 after the filter. For the knee area, 650.44, 97.61 before applying the filter, and 1013.17, 444.24 after applying the filter. For the ankle area, 206.65, 23.68 before applying the filter and 993.50, 136.11 after applying the filter. In the Long-bone examination, SNR and CNR were greatly measured when the filter was applied, confirmed the availability of using the copper additional filter.

• Korean Journal of Ichthyology
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• v.33 no.1
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• pp.1-7
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• 2021

Using stereo, light, and scanning electron microscopes, we researched the anatomical and histological structure of Chaenogobius gulosus's olfactory organ and compared it to those of sympatric gobies Luciogobius guttatus and Favonigobius gymnauchen. Results revealed the following common characteristics: i) tubular anterior nostril (AN) and flat posterior nostril (PN), ii) a single longitudinal lamella, iii) two accessory nasal sacs (ANS, ethmoidal and lacrimal), iv) abundant sensory epithelium lymphatic cells (LC), v) an eosinophil cell, and vi) a ciliary length a quarter of the knob diameter in the olfactory receptor neuron (ORN). Some characteristics are specific to C. gulosus and different from the other two gobies: i) 0.5~1.0 mm AN and 0.2~0.5 mm PN (vs. 0.2~0.3 mm and 0.2~0.3 mm in L. guttatus; 0.2~0.4 mm and 0.1~0.3 mm in F. gymnauchen), ii) two ANS (vs. absence in L. guttatus; two in F. gymnauchen), iii) abundant LC (vs. low in L. guttatus and F. gymnauchen), iv) low density non-sensory cilia on the lamellar surface (vs. high in L. guttatus; low in F. gymnauchen), and v) a quarter ciliary length to knob diameter ratio in the ORN (vs. mixture of a quarter to equal ratio in L. guttatus; two or three times in F. gymnauchen). From these results, we confirmed the C. gulosus olfactory organ has adapted anatomically and histologically to the sand-rock tidal zone.

• Journal of radiological science and technology
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• v.39 no.2
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• pp.199-208
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• 2016

$^{99}mTc-MAG_3$ Renal scan is a method that acquires dynamic renal scan image by using $^{99}mTc-MAG_3$ and dynamically visualizes process of radioactive agent being absorbed to kidney and excreted continuously. Once the test starts, ratio in both kidneys in 1~2.5 minutes was measured to obtain split renal function and split renal function can be expressed in ratio based on overall renal function. This study is based on compares split renal function obtained from data acquired from posterior detector, which is a conventional renal function test method, with split renal function acquired from the geometric mean of values obtained from anterior and posterior detectors, and studies utility of attenuation compensation depending on difference in geometric mean kidney depth. From July, 2015 to February 2016, 33 patients who undertook $^{99}mTc-MAG_3$ Renal scan(13 male, 20 female, average age of 44.66 with range of 5~70, average height of 160.40cm, average weight of 55.40kg) were selected as subjects. Depth of kidney was shown to be 65.82 mm at average for left and 71.62 mm at average for right. In supine position, 30 out of 33 patients showed higher ratio of deep-situated kidney and lower ratio of shallow-situated kidney. Such result is deemed to be due to correction by attenuation between deep-situated kidney and detector and in case where there is difference between the depth of both kidneys such as, lesions in or around kidney, spine malformation, and ectopic kidney, ratio of deep-situated kidney must be compensated for more accurate calculation of split renal function, when compared to the conventional test method (posterior detector counting).

• The Korean Journal of Nuclear Medicine
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• v.38 no.6
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• pp.492-497
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• 2004

Purpose: it is very important to differentiate breast cancer from benign mass. There are many reports to evaluate the differential diagnosis under the several diagnostic tools. We evaluated the usefulness of mammography and Tc-99m MIBI scintimammography in the differential diagnosis of breast mass and correlated with pathologic findings. Materials and Methods: This study included 80 patients (a8e: 24-72, mean: 48.4) who underwent mammography and Tc-99m MIBI scintimammography for breast masses. Scintimammographies (anterior-posterior and lateral projections) were acquired in 10 minutes and 2 hours after intravenous injection of Tc-99m MIBI. four specialists in diagnostic radioloay and nuclear medicine evaluated the findings of breast masses under the mammography and Tc-99m MIBI scintimammography, and calculated the tumor to background (T/B) ratio. The pathologic results were obtained and we statistically analyzed the correlations between pathologic results and imaging findings under the mammography and Tc-99m MIBI scintimammography by chi-square and correlation test. Results: The sensitivity, specificity, positive predictive value, and negative predictive value of mammography for detection of breast cancer were 87.5%, 56.3%, 75.0%), and 75.0% respectively. 45 cases of 80 patients were suspicious for breast cancer under the Tc-99m MIBI scintimammography. 41 cases of 45 patients were confirmed as breast cancer and the remaining 4 cases were confirmed as benign masses. The sensitivity, specificity, positive predictive value and negative predictive value of Tc-99m MIBI scintimammography for detection of breast cancer were 85.4%, 87.5%, 91.1%, and 80.8% respectively. The sensitivity of scintimammography was lower than that of mammography for detection of breast cancer, however the specificity, positive predictive value, and negative predictive value were higher. In the benign mass, the mean T/B ratio in 10 minutes was $1.409{\pm}0.30$, and that in 2 hours was $1.267{\pm}0.42$. The maximal T/B ratio of benign mass in 10 minutes was $1.604{\pm}0.42$, and that in 2 hours was $1.476{\pm}0.50$. In the malignant mass, the mean T/B ratio in 10 minutes was $2.220{\pm}1.07$, and that in 2 hours was $1.842{\pm}0.75$. The maximal T/B ratio of malignant mass was $2.993{\pm}1.94$, and that in 2 hours was $2.480{\pm}1.34$. And the T/B ratio under the early and delayed images were meaningful. Conclusion: The scintimammography is useful diagnostic tool to differentiate breast cancer from benign mass, although the sensitivity of mammography for detection of breast mass is high. Especially, the use of the T/B ratio is helpful to diagnose breast cancer.

• Journal of Chest Surgery
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• v.41 no.5
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• pp.563-567
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• 2008

Background: The histomorphological properties of the left anterior desecending artery (LAD), the left internal thoracic arteries (LITA), the radial arteries (RA) and the intercostal arteries (ICA) were studied for their use as a conduit for coronary artery bypass grafting (CABG), and we compared them with each other. Material and Method: All the vessels were harvested from nineteen cadavers (17 males and 2 females). The mid-portion of the LAD, the mid-portion of the LITA, the distal RA and the mid-portion of the 5th ICA were obtained. All of them were stained with hematoxylin-eosin and with Van Gieson's elastin stain. The morphological characteristics were examined and the thicknesses of the intima and media (I/M ratio: the intima to media ratio) were compared using one-way ANOVA tests. Result: The mean age of the cadavers was $61.5{\pm}9.6$ years. The LITA and ICA were elastic arteries, and the LAD and RA were muscular arteries. The I/M ratio showed statistically significant differences: $0.07{\pm}0.03$ in the LITA, $0.16{\pm}0.11$ in the ICA, $0.45{\pm}0.29$ in the RA and $0.93{\pm}0.52$ in the LAD, respectively. Conclusion: This study showed that the degrees of intimal hyperplasia of the CA and the various conduits for CABG were different significantly. The ICA was found to have relatively favorable characteristics as a coronary by pass conduit, but its suitability for clinical use is a challenging issue.

• Korean Journal of Ichthyology
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• v.4 no.2
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• pp.1-25
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• 1992

Taxonomic study of the five species (Acanthogobius elongata, A. flavimanus, A. lactipes, A. luridus and Synechogobius) from Korea was carried out based on morphometric, cephalic sensory canal and ecological characters. Taxonomic revision and classificational keys are provided. Synechogobius hasta is easily distinguished from four species of the genus Acanthogobius in eleven characters, i. e., the number of dorsal and anal fin rays, the transverse scales, the vertebral numbers, the formula of interneural spine of the first dorsal fin, the number of interhemal spine anterior to the first hemal spine, the number of epipleural and pleurals, the ratio of caudal peduncle length, the ratio of caudal peduncle depth and the regular variations in the ratio of body parts with the body length. In the genus Acanthobobius, A. elongata is distinguished from other 3 congeneric species in the ratio of body parts and the oculoscapular sensory canal. Moreover, A. flavimanus differs from other 3 congeneric species in the lateral scales, the transverse scales, the number of predorsal scales, the vertebral number, the number of epipleural and pleurals. Sensory papillae rows of S. hasta is not similar that of the genus Acanthogobius in having a singular sensroy papillae rows. A. elongata has no oculoscapular sensory canal D and A. flavimanus has transverse sensory papillae in cheek, and these are one of the unique characters distinguished form other congeneric species. In the spawning period inferred from gonadosomatic index, A. elongata varied from late March to late June ; A. flavimanus, January to April ; A. lactipes, May to September ; A. luridus, early May to early July and S. hasta, early March to early May.

• Restorative Dentistry and Endodontics
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• v.30 no.3
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• pp.178-183
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• 2005

This study was done to evaluate whether vital bleaching agents could influence on the translucency of the bovine enamel. The anterior bovine teeth that were extracted one day before and without any gross discoloration were obtained and then were preserved in physiologic saline. 6 mm cylindrical tooth specimens were fabricated with diamond puncher perpendicularly on labial surface of bovine tooth. After embedded in transparent acrylic resin with labial surface being exposed, they were cut to a thickness of 1.2 mm with low speed diamond saw (Isomat, Buehler Co., Lake Bluff, IL, USA). They were smoothly ground to 1 mm thickness of enamel with sandpaper. 24 specimens were randomly divided into 3 groups and control group respectively. Opalescence (10% carbamide peroxide, Ultradent, South Jordan, USA), Rembrandt (10% carbamide peroxide, DenMat, USA) and Opalescence F (15% carbamide peroxide with fluoride, Ultradent, USA) were applied on labial sides of the bovine enamel for 7 days (bleaching agents were reapplied every 24 hours) and the opposite surface was contacted to cotton that soaked in distilled water. The control group was soaked in distilled water. Three stimulus value X, Y and Z were evaluated with colorimeter (Color ' Color Differencerneter, Model TC-6FX, Tokyo Denshoku Co., Japan) on the labial surface of all specimen three times on white and black background plate before the bleaching agents were applied and on 3rd, 5th and 7th day after applied. The degree of translucency was normally assessed by measuring the inverse property, opacity (contrast ratio). 10% Opalescence, 15% Opalescence-F, and control group showed no significant variation in the translucency of bovine enamel, However Rembrandt decreased the translucency of it (p < 0.01).

• The korean journal of orthodontics
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• v.27 no.4 s.63
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• pp.643-659
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• 1997

For the total treatment of skeletal malocclusions, 3-dimensional evaluation and diagnosis are essential. Although anteroposterior discrepancies can be evaluated through various methods, the satisfactory methods for evaluations of facial asymmetry and transverse discrepancies are yet to be found. The adequate diagnosis and treatment of transverse discrepancies may be more important in the maintenance of functional occlusion as well as for the stability of results obtained from orthognathic surgery than the anteroposterior or vertical discrepancies. Since the soft tissue effects from the transverse discrepancies may not be pronounced, especially when combined with anteroposterior or vertical discrepancies which have prominent characteristics, the differentiation of their effects may be difficult from visual inspection alone. Therefore it is essential that the normal facial proportions would be established from the posteroanterior cephalometry as a reference for the accurate diagnosis and treatment. The present study evaluates 76 subjects from Yonsei University freshmen with normal facial symmetry and occlusion. Posteroanterior cephalograms were taken from the subjects and the normal values and facial proportions are obtained. The results are as follows. 1. The transverse and vortical values from posteroanterior cephalometry and their ratio, with means and standard deviations are calculated. 2. The ratio of vertical values to transverse values is 0.837 (male 0.836, female 0.841). 3. The Proportion of maxillary and mandibular widths is 0.747 (male 0.745, female 0.752), with statistically significant correlation. 4. Various degree of significant correlations are observed in the following craniofacial widths; (Cranial width, Bizygomaticofrontal suture width, Facial width, Maxillary width, Upper & Lower Intermolar width, Mandibular width). 5. Although the facial height as well as other line measurements increase as the facial widths increase, angle measurement ($Bj\ddot{o}rk$ Sum, Mandibular Plane Angle, Gonial Angle), decreases and posterior to anterior facial height ratio increases, therefore indicating the tendency for a brachycephalic facial type. These results may be used as references for the treatment planning in orthognathic and orthodontic treatments for the dentofacial deformity patients.

• Journal of the korean academy of Pediatric Dentistry
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• v.28 no.2
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• pp.247-254
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• 2001

There is a growing tendency for injury and it is essential to know about the epidemiology of the injured teeth for proper and timely treatment. Through empirical data analysis of 120 children who came to pediatric dentistry of Kangnung National University Dental Hospital, this study purposes to give an understanding about the injury and analyzes the frequency by children's sex and age, the number of injured teeth according to the area in the mouth, the types of injury, causes and places of injury, the frequency occurred by month and hour, the position of injured teeth, and the elapse of time. The main findings of this study are summarized as follows: 1. The frequency analysis by sex shows that the rate of boys is more likely to be higher than girls(1.6:1). 2. The frequency analysis by age shows that the ratio of children between aged 2~4 and 8~10 are high. 3. The number of injured teeth is generally one(51.7%). 4. Periodontal tissue injury is the main cause for the primary teeth. In case of permanent teeth, the ratio of hard tissue injury which is much increased than the case of the primary teeth, is similar to that of periodontal tissue injury. 5. The main cause of injury is fall for both dentition; In case of permanent dentition, the ratio of injury by sports is increased. 6. The place of injury for primary teeth is mainly home(38.8%); Street and school for permanent teeth(42.5% and 35%, respectively). 7. The frequency by month shows that the injury is most frequently occurred in July. 8. The frequency analysis by hour shows that injury for primary teeth mostly happens in the morning; in the afternoon for permanent teeth. 9. The position of injured teeth according to the area in the mouth is mainly maxilla anterior in both case of primary and permanent teeth and especially the ratio of central incisors is high, 10. More than half(59.2%) of patients came to the hospital within one day and the seriously injured were likely to come within one day than the slightly injured.

• Journal of the Korean Society of Radiology
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• v.16 no.7
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• pp.897-904
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• 2022

The purpose of this study is to compare the difference in dose and image quality when applying the diagnostic reference level (DRL) test conditions for head radiography in a digital radiation environment and the test conditions currently applied in clinical practice. I would like to review the conditions of radiographic examination. In this study, the head model phantom was targeted, and the investigation conditions were divided into clinical conditions (Clinic), DRL value (DRL₇₅), and DRL average value (DRL_mean). For dose, Enterance surface dose (ESD) was measured, and for image quality, signal-to-noise ratio and contrast-to-noise ratio were measured and analyzed for comparison. The average values of skull anterior posterior(AP) ESD according to the changes in test conditions were Clinic 1214.03±4.21 µGy, DRL₇₅ 3017.83±8.14 µGy, DRL_mean 2283.50±7.09 µGy, and skull lateral (Lat). The average value of ESD was statistically significant with Clinic 762.79±3.54 µGy, DRL₇₅ 2168.57±10.83 µGy, and DRL_mean 1654.43±6.48 µGy (p<0.01). The average values of SNR and CNR measured in the orbital, maxillary sinus, frontal sinus, and sella turcica were statistically significant (p<0.01). As a result of this study, compared to DRL, the conditions used in clinical practice showed lower dose levels of about 58% for AP and about 70% for Lat., and there was no qualitative difference in terms of image quality. Through this study, it is necessary to consider a new diagnostic reference level suitable for the digital radiation environment, and it is considered that the dose should be reduced accordingly.