• Korean Journal of Radiology
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• v.24 no.12
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• pp.1173-1175
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• 2023

• Journal of the Korean Society of Radiology
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• v.13 no.5
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• pp.773-778
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• 2019

Images using X-rays are essential to diagnosis, but noise is inevitable in the image. To compensate for this, a total variation (TV) algorithm was presented to reduce the patient's exposure dose while increasing the quality of the images. The purpose of this study is to verify the effect on the image quality in radiographic imaging according to the thickness of the additional filtration plate through simulation, and to evaluate the usefulness of the TV algorithm. By using the Geant4 Application for Tomographic Emissions (GATE) simulation image, the actual size, shape and material of the Polymethylmethacrylate (PMMA) phantom were identical, the contrast to noise ratio (CNR) and coefficient of variation (COV) were compared. The results showed that the CNR value was the highest and the COV the lowest when applying the TV algorithm. In addition, we can acquire superior CNR and COV results with 0 mm Al in all algorithm cases.

• Journal of the Korea Convergence Society
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• v.10 no.12
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• pp.143-149
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• 2019

Radiologist image perceived by radiology students plays important role for them in establishing a positive Radiology professionalism as well as having a satisfaction on their job. Thus, this study was conducted to examine the image of Radiologist perceived by both radiology students. Q-methodology was used for this study. 110 Q statements were extracted from qualitative survey from 110 radiology students. The selected statements were reviewed and revised by experts and 33 Q samples were finally selected. Then, 30 radiology students were recruited for this study and were asked to arrange the statement cards on a 9 point scale, which shaped a normal distribution. The data were then analyzed by using PQ method program. As a result, two types of Radiologist's images were explored: 'professional technology type', 'safety of patient type' The results of this study will be helpful to provide the direction that we have to pursue regarding educational and political perspectives.

• Journal of the Korean Society of Radiology
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• v.15 no.1
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• pp.21-28
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• 2021

Computed tomography (CT) has the problem of having more radiation exposure compared to other radiographic apparatus. There is a low-dose imaging technique for reducing exposure, but it has a disadvantage of increasing noise in the image. To compensate for this, various noise reduction algorithms have been developed that improve image quality while reducing the exposure dose of patients, of which the median modified Wiener filter (MMWF) algorithm that can be effectively applied to CT devices with excellent time resolution has been presented. The purpose of this study is to optimize the mask size of MMWF algorithm and to see the excellence of noise reduction of MMWF algorithm for existing algorithms. After applying the MMWF algorithm with each mask sizes set from the MASH phantom abdominal images acquired using the MATLAB program, which includes Gaussian noise added, and compared the values of root mean square error (RMSE), peak signal-to-noise ratio (PSNR), coefficient correlation (CC), and universal image quality index (UQI). The results showed that RMSE value was the lowest and PSNR, CC and UQI values were the highest in the 5 x 5 mask size. In addition, comparing Gaussian filter, median filter, Wiener filter, and MMWF with RMSE, PSNR, CC, and UQI by applying the optimized mask size. As a result, the most improved RMSE, PSNR, CC, and UQI values were showed in MMWF algorithms.

• Archives of Plastic Surgery
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• v.37 no.4
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• pp.375-379
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• 2010

Purpose: The nasal bone is the most frequently fractured facial bone. Discordance between the CT reading by the radiologist and the diagnosis by the plastic surgeon is not uncommon. This study examined the discordance and proposes a method for reducing the rate of discordance. Methods: The CT readings by the radiologist were compared with the diagnosis by the plastic surgeon in 716 patients with a clinically suspected nasal bone fracture. The CT reading was classified as the following: a nasal bone fracture, suspicious nasal bone fracture, old nasal bone fracture, no nasal bone fracture. The sensitivity, specificity and positive predictive value of the CT reading were calculated. Results: A nasal bone fracture was diagnosed in 646 patients by the plastic surgeon and confirmed intraoperatively. The reading of a "nasal bone fracture", "suspicious nasal bone fracture", "old nasal bone fracture" and "no nasal bone fracture" was 85.8%, 4.6%, 0.6% and 9.1% respectively. The sensitivity and specificity of the CT reading were 95.0% and 92.9%, respectively. The positive predictive value of the CT reading was 99.3%. The reading of "nasal bone fracture" that was not a nasal bone fracture clinically was 17.1% (12 of 70), and the reading of "no nasal bone fracture" or "old nasal bone fracture" that was found to be a nasal bone fracture clinically was 3.3% (21 of 646). The discordance rate between the CT reading by the radiologist and the diagnosis by the plastic surgeon was 4.6%. Conclusions: To reduce the discordance rate, we propose to hold a meeting with the plastic surgery-radiology staff to communicate the information regarding a suspicious or old nasal bone fracture.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.27 no.1
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• pp.179-188
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• 1997

This study was intended to compare the diagnostic ability between Waters' radiograph and CT in the diagnosis of midfacial fracture. The study group included 44 patients(male:32, female :12, age range :16-74 years old) with facial injury who underwent surgery. Waters' radiograph and both axial and coronal scanning were performed before surgery. Three oral radiologists and three non-oral radiologist interpreted 44 Waters' radiographs and 88 CT in three ways; 1) interpretation using Waters' radiograph only, 2) interpretation using CT only, 3) interpretation using Waters' radiograph and CT. The interpretation sites were confined to the walls of maxillary sinus; anterior, posterior, medial, lateral and superior wall. ROC curves were made with the findings during surgery as a gold standard except the posterior wall, where the joint evaluation of Waters' radiograph and CT by other three oral radiologists was used. ROC areas were compared according to the interpreting methods, the interpretation sites, and groups (R group ; oral radiologist group, N group ; non-oral radiologist group). The obtained results were as followed : 1. The diagnostic ability of CT only and Waters' radiograph and CT was higher than Waters' radiograph only in both groups(P<0.05). But there was no difference between CT only and Waters' radiograph and CT. 2. Generally, the diagnostic ability for the lateral antral wall was the highest and that for the posterior antral wall was the lowest in both groups(P<0.05). 3. In R group, for the anterior antral wall the diagnostic ability using CT only was increased but for the medial, lateral and superior antral walls the diagnostic ability was increased in only using Waters' radiograph and CT. 4. In N group, for the anterior and medial walls the diagnostic ability using CT only was increased. But for the posterior, lateral and superior antral walls there were no difference among three interpreting methods. 5. The diagnostic ability of R group was higher than N group in all interpreting methods.

• The Korean Journal of Health Service Management
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• v.6 no.1
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• pp.105-116
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• 2012

Some radiology majors at three-year colleges in Daegu and Gyeongsangbuk-Do Province were selected for the research. The survey was conducted by explaining its objectives and distributing the self-administered questionnaires from March 7 to 30, 2011; then, the final analysis was carried out on 122 copies, drawing the following conclusions : 1) 31.1% of the radiology majors were motivated to enter their department by good employment after graduation, and 37.7% were getting information from their parents or relatives in selecting their major. 2) The majority of the respondents wanted to get a job in a big city after graduation on the basis of good pay. 3) Department selection was significantly affected by transportation, department and school image, and school facilities, and the effects were higher among females. 4) Department satisfaction was significantly affected by professor satisfaction, prospects for the department, and support for employment activities, and the effects were higher among females. 5) School satisfaction was significantly affected by satisfaction with school selection decision, good selection, and school environment, and the effects were higher among females. 6) Females were found to have higher professional consciousness as a radiologist, showing statistically significant differences: "the occupation as a radiologist will continue to be developed" at $3.97{\pm}.837$ for males and at $4.55{\pm}.663$ for females and "the occupation as a radiologist is stable and will be help get a life-long job" at $3.82{\pm}.9.08$ for males and at $4.41{\pm}.787$ for females.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.50 no.1
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• pp.49-55
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• 2024

Neurofibromatosis type 1 (NF1) is an autosomally dominant tumor suppressor syndrome and multisystem disease. Central giant-cell granulomas (CGCGs) can be seen in patients with NF1. A 21-year-old female was diagnosed with two CGCGs, one in the mandible and then one in the maxilla, in a 7-year period. Increased incidence of CGCGs in NF1 patients was thought to be caused by an underlying susceptibility to developing CGCG-like lesions in qualitatively abnormal bone, such as fibrous dysplasia. However, germline and somatic truncating second-hit mutations in the NF1 gene have been detected in NF1 patients with CGCGs, validating that they are NF1-associated lesions. Oral manifestations in patients with NF1 are very common. Knowledge of these manifestations and the genetic link between NF1 and CGCGs will enhance early detection and enable optimal patient care.

• Journal of Periodontal and Implant Science
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• v.36 no.1
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• pp.147-154
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• 2006

Surgical intervention in the posterior maxillary region requires detailed knowledge of maxillary sinus anatomy and the possible anatomical variations. This study evaluated the incidence, location of maxillary sinus septa by using radiographic (panoramic radiography and computed tomography) findings and comparison of panoramic radography with CT in antral anatomical variation. This study was based on data from 70 sinuses in partial dentate maxilla. The sample consisted of 61 patients(25 women and 36 men, with ages ranging between 19 and 77 years and a mean age of $49.4{\pm}11.3$ years) who were being treatment-planned to receive implant-supported restorations. First, the panoramic images were examined for the presence of antral septa by radiologist and examiner who don't know about CT findings. And incidence of antral septa was evaluated using an axial plane of CT image. The incidence of septa was compared between panoramic radiography and CT. The accuracy of the incidence was compared between radiologists and dentists. A total of 20 septa were found in 70 sinuses on CT image and the prevalence of one or more septa per sinus was found to be 28.6%. The assumed incidence of septa on panoramic radiography was $27.6%{\pm}2.2%$ in radiologist and $31.9%{\pm}5.8%$ in dentists. Erroneous diagnosis rate was 11.42% in radiologist and 15.96% in dentists. 40% of antral septa were located in the anterior(premolar) region, 30% of septa were located in the middle(first molar) and posterior(second molar) region separately. Prior to implant placement, it seems appropriate to consider panoramic radiography as a standard radiographic examination and periapical radiographs may be used to complete the findings in regions not sharply depicted in the panoramic radiograph. And cross-sectional imaging should be used in sites with severe bone loss and close proximity of the maxillary sinus.

• The Korean Journal of Health Service Management
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• v.7 no.1
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• pp.107-118
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• 2013

The purpose of this study is to grasp the image of radiologists perceived by college students of radiology. The survey subjects of this study were selected college students with major in radiology with 3-year system who are attending universities where are located in Daegu and Gyeongbuk area. As for distribution and collection of questionnaire, the objective of research was explained from April 2, 2012 to April 30. 220 people's questionnaires were finally analyzed with a self-administrative method after being widely distributed. Statistical analysis was carried out frequency analysis, t-test, ANOVA, and correlation analysis. To examine factors of having influence upon the image of radiologists, the multiple regression analysis was carried out. As for survey subjects' general characteristics, gender was indicated to be 58.2% for men and 41.8% for women. School year accounted for 38.2% for freshman, 29.1% for sophomore, and 32.7% for junior. Age was the largest in under 21 years old with 43.6%. The next was in order of over 23 years old with 32.7% and 22 years old with 20%. As a result of research, the image of radiologists was being perceived positively. The radiologist was being recognized as a specialist who is sincere oneself and has strong responsibilities, does valuable and worthwhile work, and has the matured professional knowledge. However, the individual image of radiologists was a little negative. Accordingly, to promote the individual image of radiologists, a specific and positive strategy is needed for approaching people as the specialized job with autonomy and responsibility as well as radiologist oneself.