• Tuberculosis and Respiratory Diseases
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• v.52 no.1
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• pp.46-53
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• 2002

Background: Pulmonary aspergilloma is relatively common in korea. It arises from the colonization and proliferation of Aspergillus in preexisting lung parenchymal cavities, in particular tuberculosis. The most common symptom in this disorder is hemoptysis, which mayor may not be massive and life threatening. A routine chest radiography and computed tomography (CT) are the most important diagnostic procedures. A surgical resection of the aspergilloma has recently been recommended, because of the relatively low incidence of postoperative complications than in the past. A more concentrated sample of patients with aspergilloma, who either underwent a thoracotomy or tested positive for aspergillus antibodies, were reviewed. Method : The medical records of twenty-two patients with aspergilloma, who had a proven thoracotomy (9 cases), or who tested positive for the diagnostic procedure and/or aspergillus antibodies (13 cases) from January 1995 to December 2000, were reviewed retrospectively. Results : The most common underlying lung disease was a current or old healed tuberculosis, and 3 patients had cultures of mycobacterium other than tuberculosis (MOTT). The mean time until the aspergilloma was detected 5.91 years in the healed tuberculosis cases. The others cases involved a lung abscess, bronchiectasis and without lung disease. The extrapulmonary disease was alcoholism and diabetes. Hemoptysis was most common in 72.7%. A computed tomography (CT) is useful for diagnosis. The right upper lobe, especially the posterior segment, is the most common location. Bronchial artery embolization is ineffective for a long term follow-up. A lobectomy is most common in a thoracotomy, and intra-operative and post-operative complications are rare. During follow-up, the mortality rate, not from the aspergilloma but from respiratory failure, was 13.6%. Conclusion : Aspergilloma is a common cavitary lung disease, It mainly arises from tuberculosis, either current or healed, but extra-pulmonary disease including alcoholism or diabetes are other possible risk factors. Their most common problem in aspergilloma is hemoptysis. Surgery has a low risk of post-operative complications and is recommended in relatively preserved lung function or healthy patients. Medical maneuvers including embolization, and the local insertion of certain materials needs to be studied more closely.

• Tuberculosis and Respiratory Diseases
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• v.48 no.1
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• pp.45-53
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• 2000

Background: The literature on variations of rib is limited. Very little has been written in the radiological journal of this country on the subject. It seemed of interest to investigate the nature and incidence of congenital variations in a series of routine chest roentgenograms. The topic of rib variations has not been covered extensively in the radiological journals in Korea. This has presented an opportunity to investigate the nature, type, shape and incidences of congenital rib variations in normal Korean adults from a series of routine roentgenograms. Methods: Chest radiographs of 5,000 adults, who visited our hospital for a routine check-up or for employment physical examinations from January 1996 to September 1998, were consecutively reviewed. The sex distribution consisted of 2,827 male males and 2,173 female females(ratio of 1.3:1) with the age range aged between 19 and 65 years(mean age: 34.6 years) were included. The chest PAs were analyzed for the presence, type, location, and shape of the rib variations. From this data the incidence of each type of variations was calculated. Results: Seventy-six of the 5,000 adults(1.52%), 63 male(2.23%) and 13 female(0.6%), showed 88 cases of rib variation(Table 1). The most common variation was the bifid rib(n=35), followed by hypoplasia of the rib(n=22), flaring of the rib(n=18), bridging of the ribs(n=7), cervical ribs(n=3), and fusion of between ribs(n=3)(Table 2). The bifid rib(Table 1) was found most frequent in the right fourth rib(12/35, 34.3%), followed by the left fifth rib(6/35, 17.1%) and right third rib(6/35, 17.1%). Hypoplasia of the rib was common in first rib(20/22, 90.9%). Flaring of the rib was common at fourth rib(8/18, 44.4%, right and left combined), and bridging between ribs was common between first and second rib(3/7, 42.9%). Conclusion : The percentage of incidence of rib variations in adults was 1.52%. Bifid rib was the most common variation, followed by hypoplasia, flaring, bridging, cervical rib, and fusion of ribs, in decreasing order.

• The Journal of Korean Academy of Prosthodontics
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• v.41 no.2
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• pp.182-206
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• 2003

Statement of problem : Successful osseointegration of endosseous threaded implants is dependent on many factors. These may include the surface characteristics and gross geometry of implants, the quality and quantity of bone where implants are placed, and the magnitude and direction of stress in functional occlusion. Therefore clinical quantitative measurement of primary stability at placement and functional state of implant may play a role in prediction of possible clinical symptoms and the renovation of implant geometry, types and surface characteristic according to each patients conditions. Ultimately, it may increase success rate of implants. Purpose : Many available non-invasive techniques used for the clinical measurement of implant stability and osseointegration include percussion, radiography, the $Periotest^{(R)}$, Dental Fine $Tester^{(R)}$ and so on. There is, however, relatively little research undertaken to standardize quantitative measurement of stability of implant and osseointegration due to the various clinical applications performed by each individual operator. Therefore, in order to develop non-invasive experimental method to measure stability of implant quantitatively, the resonance frequency analyzer to measure the natural frequency of specific substance was developed in the procedure of this study. Material & method : To test the stability of the resonance frequency analyzer developed in this study, following methods and materials were used : 1) In-vitro study: the implant was placed in both epoxy resin of which physical properties are similar to the bone stiffness of human and fresh cow rib bone specimen. Then the resonance frequency values of them were measured and analyzed. In an attempt to test the reliability of the data gathered with the resonance frequency analyzer, comparative analysis with the data from the Periotest was conducted. 2) In-vivo study: the implants were inserted into the tibiae of 10 New Zealand rabbits and the resonance frequency value of them with connected abutments at healing time are measured immediately after insertion and gauged every 4 weeks for 16 weeks. Results : Results from these studies were such as follows : The same length implants placed in Hot Melt showed the repetitive resonance frequency values. As the length of abutment increased, the resonance frequency value changed significantly (p<0.01). As the thickness of transducer increased in order of 0.5, 1.0 and 2.0 mm, the resonance frequency value significantly increased (p<0.05). The implants placed in PL-2 and epoxy resin with different exposure degree resulted in the increase of resonance frequency value as the exposure degree of implants and the length of abutment decreased. In comparative experiment based on physical properties, as the thickness of transducer increased, the resonance frequency value increased significantly(p<0.01). As the stiffness of substances where implants were placed increased, and the effective length of implants decreased, the resonance frequencies value increased significantly (p<0.05). In the experiment with cow rib bone specimen, the increase of the length of abutment resulted in significant difference between the results from resonance frequency analyzer and the $Periotest^{(R)}$. There was no difference with significant meaning in the comparison based on the direction of measurement between the resonance frequency value and the $Periotest^{(R)}$ value (p<0.05). In-vivo experiment resulted in repetitive patternes of resonance frequency. As the time elapsed, the resonance frequency value increased significantly with the exception of 4th and 8th week (p<0.05). Conclusion : The development of resonance frequency analyzer is an attempt to standardize the quantitative measurement of stability of implant and osseointegration and compensate for the reliability of data from other non-invasive measuring devices It is considered that further research is needed to improve the efficiency of clinical application of resonance frequency analyzer. In addition, further investigation is warranted on the standardized quantitative analysis of the stability of implant.

• Journal of Conservation Science
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• v.25 no.1
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• pp.1-16
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• 2009

Jeollabuk-do is bounded by the sea, and Mahan Baekje culture have been established around a wide plain. Also, in southeastern, it was closed by Gaya kingdom where iron culture was prosperous at that time, a variety of the handles of swords with round pommel is excavated at present. The handles of swords with round pommel is the best amount of excavated objects among the swords with round pommel and producted object for the time. It supposes them to become the foundation of making the decorated swords with round pommel. But, the handles of swords with round pommel that don't have a pattern in handle is indifferent to study because the production method is simple in spite of that the value of archaeological data is sufficient. Therefore, in this study, it examined changed production techniques with the change of times concerning the handles of swords with round pommel of Mahan Baekje Gaya period(before 6C) excavated from Jeollabukdo through using X-rays in order to clarify a variety of production techniques of the handles of swords with round pommel correctly in accordance with a period of production and excavated place. As a result, identified production techniques using X-rays of the handles of swords with round pommel excavated around remains of Mahan Baekje Gaya period shows that production progress improved in order of all-in-one shape, hammer welding shape of the handle of round pommel, and two in body formation in accordance with age. Especially, in two in body shape, it products the handle of round pommel separately, after that it welds the handle of swords and then links the sword blade like a riveting or bottleneck and so on. Despite of improved hammer welding technique, the reason why it didn't utilize is it regards as inlay or gilt will be damaged. And it is judged by using riveting or bottleneck. Also, it appears to techniques of metal craft such as decoration of the handle, decoration of point of sword, inlay, and silver-plating in the period of appearing two in body shape. As clarifying correctly, it provides fundamental database of scientific research about a study of production techniques of handle of swords with round pommel.

• Journal of radiological science and technology
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• v.33 no.4
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• pp.327-334
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• 2010

Exposure during childhood results in higher risk for certain detrimental cancers than exposure during adulthood. We measured entrance skin dose (ESD) under 7-year children undergoing chest imaging and compared the relationship between ESD and age, height, weight, chest thickness. Though it is important to measure chest thickness for setting up the exposure condition of chest examination, it is difficult to measure chest thickness of children. We set up exposure parameters according to age because chest thickness of children has correlation with age. In the exposure parameters, for chest A-P examination under 2 year-children, tube voltage (kVp) in hospital A was higher than that in hospital B while tube current (mAs) was higher in hospital B, thus the ESD values were about 1.7 times higher in hospital B. However, for chest P-A examination over 4 year-children, the tube voltage was 7 kVp higher in hospital B, the tube current were same in all two systems, and focus to image receptor distance (FID) in hospital B (180 cm) was longer than that in hospital A (130 cm), thus the ESD values were 1.4 times higher in hospital A. For same ages, the ESD values for chest A-P examinations were higher than those for chest P-A examinations. Comparing ESD according to age, ESD values were $154{\mu}Gy$, $194{\mu}Gy$ and $138{\mu}Gy$ for children under 1 year, 1 to under 4 years and 4 to under 7 years of age, respectively. These values were lower than reference level ($200{\mu}Gy$) recommended in JART (japan association of radiological technologists), however these were higher than reference values recommended by EC (european commission), NRPB (national radiological protection board) and NIFDS (national institute of food & drug safety evaluation). In conclusion, the values of ESD were affected by exposure parameters from radiographer's past experience more than x-ray system. ESD values for older children were not always higher than those for younger children. Therefore we need to establish our own DRLs (diagnostic reference levels) according to age of the children in order to optimize pediatric patient protection.

• Journal of Chest Surgery
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• v.39 no.3 s.260
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• pp.220-225
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• 2006

Background: Spontaneous pneumomediastinum is an uncommon, benign, self-limited disorders that usually occurs in young adults without any apparent precipitating factors or disease. The purpose of this study was to review our experience in dealing with this entity and describe a reasonable course of assessment and management. Material and Method: A retrospective case series was conducted to identify adults patients with SPM who were diagnosed and treated in a single institution between 2001 and 2005. Result: Fifteen patients were identified who included 14 men and 1 women with a mean age of 26 years. Presenting symptoms were chest pain in 12 patients ($80\%$), dyspnea in 5 patients ($33\%$), and throat discomfort in 4 patients ($26\%$). Two cases were associated with use of inhalational drugs and 3 cases were associated with exercise. The predisposing factors were asthma, excessive exercise, and vomiting in spontaneous pneumomediastinum. The physical findings were subcutaneous emphysema in 10 patients ($77\%$). Chest radiography and computerized tomography were the diagnostic methods in all cases with CT scan revealing six cases with associated pulmonary abnormalities. Esophagogram and flexible bronchoscopy were selectively used. Fifteen patients ($100\%$) were admitted to the hospital. Their mean hospital stay was 3 days. All patients were conservatively treated. In a follow-up of 3 years no complications or recurrences were observed. Conclusion: Most simple spontaneous pneumomediastinum cases were benign diseases and most of them ($77\%$) had shown typical chest pain, dyspnea and subcutaneous emphysema. Inhalational drug use was not a major cause of SPM; however, increased use of bronchoinhalers was a suspicious cause of SPM.

• Journal of the korean academy of Pediatric Dentistry
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• v.48 no.2
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• pp.221-228
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• 2021

The aim of this study was to evaluate the use of easily accessible machine learning application to identify mesiodens, and to compare the ability to identify mesiodens between trained model and human. A total of 1604 panoramic images (805 images with mesiodens, 799 images without mesiodens) of patients aged 5 - 7 years were used for this study. The model used for machine learning was Google's teachable machine. Data set 1 was used to train model and to verify the model. Data set 2 was used to compare the ability between the learning model and human group. As a result of data set 1, the average accuracy of the model was 0.82. After testing data set 2, the accuracy of the model was 0.78. From the resident group and the student group, the accuracy was 0.82, 0.69. This study developed a model for identifying mesiodens using panoramic radiographs of children in primary and early mixed dentition. The classification accuracy of the model was lower than that of the resident group. However, the classification accuracy (0.78) was higher than that of dental students (0.69), so it could be used to assist the diagnosis of mesiodens for non-expert students or general dentists.

• Journal of the Korean Society of Radiology
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• v.13 no.1
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• pp.111-118
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• 2019

Chest digital tomosynthesis has become a practical imaging modality because it can solve the problem of anatomy overlapping in conventional chest radiography. However, because of both limited scan angle and finite-size detector, a portion of chest cannot be represented in some or all of the projection. These bring a discontinuity in intensity across the field of view boundaries in the reconstructed slices, which we refer to as the truncation artifacts. The purpose of this study was to reduce truncation artifacts using a weighted normalization approach and to investigate the performance of this approach for our prototype chest digital tomosynthesis system. The system source-to-image distance was 1100 mm, and the center of rotation of X-ray source was located on 100 mm above the detector surface. After obtaining 41 projection views with ${\pm}20^{\circ}$ degrees, tomosynthesis slices were reconstructed with the filtered back projection algorithm. For quantitative evaluation, peak signal to noise ratio and structure similarity index values were evaluated after reconstructing reference image using simulation, and mean value of specific direction values was evaluated using real data. Simulation results showed that the peak signal to noise ratio and structure similarity index was improved respectively. In the case of the experimental results showed that the effect of artifact in the mean value of specific direction of the reconstructed image was reduced. In conclusion, the weighted normalization method improves the quality of image by reducing truncation artifacts. These results suggested that weighted normalization method could improve the image quality of chest digital tomosynthesis.

• Journal of the Korean Orthopaedic Association
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• v.56 no.2
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• pp.150-156
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• 2021

Purpose: To determine how the location, displacement, intra-articular involvement, comminution of a 5th metatarsal base fracture affect results of early weight-bearing treatment. Materials and Methods: From January 2013 to July 2017, 34 cases of 34 patients diagnosed with a fracture of the zone I and II 5th metatarsal base were enrolled. The mean follow-up period was 13 months (6-15 months). One patient was excluded as a refracture during the follow-up period, and 33 patients underwent conservative treatment. Anteroposterior, lateral, and simple oblique radiography and computed tomography of the foot were performed to evaluate the location and displacement of the fracture, the degree of joint involvement, and comminution. In all 33 patients, a short leg cast or boot brace was selected immediately after the injury, tolerable weight bearing was allowed. If the pain disappeared, full weight bearing was performed after wearing a plain shoe or postoperative shoe. As a clinical result, the American Orthopedic Foot and Ankle Society (AOFAS) score was evaluated at the final follow-up. During outpatient follow-up, a simple radiograph of the foot was taken to confirm the time of radiological bone union and return to work. Results: Nine males and 24 females, with an average age of 48.7 years, were enrolled in the study. Twenty-four patients had zone I fractures, and nine patients had zone II fractures. Twenty-two out of 33 patients had a fracture displacement of 2 mm or more. Nine and five patients had joint involvement and comminution, respectively. There was a statistically significant return to work from zone I to zone II. The AOFAS score was excellent at the final follow-up and there was no significant difference. When classifying and comparing the degree of fracture displacement, joint involvement, and comminution, there were no significant differences in the radiological union time and return to work. In all cases, satisfactory results were obtained at the final follow-up. Conclusion: Satisfactory clinical results can be obtained by allowing early weight-bearing regardless of the fracture location, displacement, joint involvement, or comminution in zone I and II 5th metatarsal base fractures.

• Journal of the Korean Society of Radiology
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• v.17 no.7
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• pp.1149-1155
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• 2023

This study aims to investigate the effect of changes in the Sub ROI on exposure index(EI) and to present indicators of changes in EI values that may occur when changing Sub ROI in clinical practice. This study was conducted on a subject of 20 cm of acrylic for a setting similar to abdominal radiography, and the specifications of one acrylic sheet is 20 × 20 × 5 cm. The survey conditions were the same as 80 kVp , 320 mA, 25 ms, SID 110 cm and the Sub ROI obtained 30 images for each type using five types provided by the equipment company. The EI value provided by the equipment and entrance skin exposure(ESE) were compared and analyzed. The mean value of EI according to the change in Sub ROI was 101.18±0.27 for LS, 106.57±0.31 for AEC, 107.74±0.39 for VR, 107.90±0.38 for HR, and 109.72±0.32 for SS (p<0.01). The average value of ESE by sub ROI type (LS, AEC, VR, HR, SS) was measured to be 476.45±1.71 μGy, 476.92±1.48 μGy, 476.14±2.30 μGy, 475.61±1.96 μGy, and 477.14±1.46 μGy, with statistically significant differences (p<0.01). As a result of this study, the EI according to the sub ROI type is based on LS(109.72), which represents the minimum value. AEC increased 5.3%, VR increased 6.4%, HR increased 6.6%, SS increased 8.4%, and overall, increased by about 5.3%. As for the average value of ESE, HR(475.61 μGy)type showed the minimum value, and based on this, AEC increased 0.27%, VR increased 0.11%, LS increased 0.17%, SS increased 0.32%, and overall, increased by about 0.17%.