• Imaging Science in Dentistry
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• 제52권1호
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• pp.1-9
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• 2022

Purpose: This systematic review aimed to compare assessments of the healing of periapical endodontic surgery using conventional radiography and cone-beam computed tomography (CBCT). Materials and Methods: This review of clinical studies was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) checklist. All articles published from 1990 to March 2020 pertaining to clinical and radiographic healing assessments after endodontic surgery using conventional radiography and CBCT were included. The question was "healing assessment of endodontic surgery using cone-beam computed tomography." The review was conducted by manual searching, as well as undertaking a review of electronic literature databases, including PubMed and Scopus. The studies included compared radiographic and CBCT assessments of periapical healing after periapical endodontic surgery. Results: The initial search retrieved 372 articles. The titles and abstracts of these articles were read, leading to the selection of 73 articles for full-text analysis. After the eligibility criteria were applied, 11 articles were selected for data extraction and qualitative analysis. The majority of studies found that CBCT enabled better assessments of healing than conventional radiography, suggesting higher efficacy of CBCT for correct diagnosis and treatment planning. A risk of bias assessment was done for 10 studies, which fell into the low to moderate risk categories. Conclusion: Three-dimensional radiography provides an overall better assessment of healing, which is imperative for correct diagnosis and treatment planning.

• Journal of Periodontal and Implant Science
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• 제25권1호
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• pp.67-75
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• 1995

The progress of periodontal disease and the wound healing process after treatment result in alveolar bone bone change. So, detection of it is very important in the diagnosis and the radiograph of periodontal disease. Various effects have been made to assess the subtle alveolar bone change and digital subtraction radiography (DSR) has been reported to be the best method in evaluating it qualitatively and quantitatively. The present study was performed to estimate the detectable alveolar bone change qualitatively with digital subtraction radiography. For the in vitro study, 10 intraoral standard radiographs were taken from porcine dry mandible which a rectangular cortical bone chip of 0.1mm to 1.0mm thickness with 0.1mm increment was attached on the buccal surface. The radiographs without and with bone plates were reviewed at the same time by 10 observers and requested to detect the presence of cortical bone plates. Digital Subtraction radiograph was reviewed subsequently by using the DSR system(digital converter-256 grey-levels,DT 2851,Data Translation Co., U.S.A;IBM 386 ; CCD camera, FOTOVIX, Tamrom Co., Japan). The detectable thickness of cortical bone plate was O.4mm on the intraoral radiograph and 0.2mm on the subtaction images. For the human study, radiographs were taken from patients by using intraoral film holding device and aluminum reference wedge before and 3 month after bone graft and 1 week after osteoplasty. The grey level change was estimated in the subtraction images and calculated to aluminum equivalent thickness. The grey level of the grafted site was higher that that of healthy controls. Average grey levels of change on healthy controls were O.48mm aluminum equivalent. However, the amount of changes in grafted sites were 1.87mm aluminum thickness equivalent and in the site of osteoplasty were -1.49mm aluminum thickness equivalent. In conclusion, digital subtraction radiography was more effective in detecting as subtle change of alveolar bone than intraoral standard radiography. With the aid of quantitative analysis of digital subtraction radiography, alveolar bone resorption of apposition can be estimated during diagnosis and treatment of periodontally diseased patients.

• 한국방사선학회논문지
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• 제8권4호
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• pp.203-210
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• 2014

X선을 이용한 chest radiography는 일반적으로 180 cm의 SID에서 실시되고 있다. digital chest radiography에서 AEC를 적용하고 120 kVp, 320 mA에서 SID를 180 cm부터 340 cm까지 20 cm 단위로 증가시켜 가며 영상의 질과 환자선량의 관계를 알아보았다. chest phantom 영상의 정성적인 영상평가를 위해 VGA를, 정량적인 평가를 위해 SNR을 분석하였다. 선량은 ESAK로 측정하고 effective dose는 PCXMC를 이용하였다. 연구결과 일반적으로 시행되는 SID 180 cm를 기준으로 했을 때, ESAK의 경우 240 cm, 280 cm, 320 cm에서 각각 8.7%, 11.47%, 13.56%의 유의한 감소가 있었다. effective dose의 경우 전신에 대해 2.89%, 4.67%, 6.41%의 감소, 폐에서 5.08%, 6.98%, 9.6%의 감소가 관찰되었다. SNR의 경우 각각 9.04%, 8.24%, 11.46%의 감소가 관찰되었으며 특히, SID 260 cm ~ 300 cm 구간에서 8.03%의 작은 감소가 나타났고 SID 340 cm까지도 5.24로 5이하로 감소되지 않았다. VGA에서는 통계적으로 유의한 차이가 없는 진단적 가치가 높은 영상으로 평가되었다. 따라서 eigital chest radiography에서 SID를 300 cm까지 증가시킴으로 화질의 저하 없이 환자선량을 감소시킬 수 있을 것으로 기대된다.

• 대한안전경영과학회지
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• 제13권2호
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• pp.91-96
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• 2011

The purpose of this study was to minimize of entrance surface dose (ESD) at the eye using high kVp technique in the computed radiography. We used REX-650R (Listem, Korea) general X-ray unit, and external detector with ESD dosimeter of Piranha 657 (RTI Electronics, Sweden). We used head of the whole body phantom. The total 64 images of X-ray anterior-posterior of skull were acquired using the film/screen (F/S) method and the digital of computed radiography method. The three radiology professor of more 10 years of clinical career evaluated a X-rays images in the same space by 5-point scale. The external detector was performed measurement of ESD of three times by same condition on the eye of the head phantom. The good image quality in the F/S method (90 kVp, 2.5 mAs) showed at the minimized ESD of 0.310 ${\pm}$ 0.001 mGy. the good image quality in the computed radiography method (90 kVp, 2.0 mAs) showed at the minimized ESD of 0.180 ${\pm}$ 0.002 mGy (P = 0.002). Finally the radiation dose could reduced about 50% in the computed radiography method more than the F/S method. In addition the eye entrance surface dose using high kVp technique with the computed radiography was reduced 92% more than conventional technique (F/S method).

• 대한의용생체공학회:의공학회지
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• 제28권2호
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• pp.199-204
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• 2007

In digital radiography, to improve the contrast of digital radiography image, the multi-scale nonlinear amplification algorithm based on unsharp masking is one of the major image enhancement algorithms. In this paper, we used the Laplacian pyramid to decompose a digital radiography(DR) image. In our simulation, the DR image was decomposed into seven layers and the coefficients of the each layer was amplified with nonlinear function. We also imported a noise containment algorithm to limit noise amplification. To enhance the contrast of image, we proposed a new adaptive non-linear gain amplification coefficients. As a result of having applied to some clinical data, a detail visibility was improved significantly without unacceptable noise boosting. Images that acquired with the proposed adaptive non-linear gain coefficients have shown superior quality to those that applied similar gain control method and expected to be accepted in the clinical applications.

• Imaging Science in Dentistry
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• 제39권4호
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• pp.195-198
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• 2009

Purpose : To establish reference doses of periapical radiography in Chonnam Province, Korea. Materials and Methods : The target-skin distances were measured for dental patient's 1235 exposures including 345 mandibular molar areas. Each periapical radiation exposure was simulated with exactly the same patients exposure parameters and the simulated radiation doses were measured utilizing Mult-O-Meter (Unfors Instruments, Billadal, Sweden). The measurements were done in 44 dental clinics with 49 dental x-ray sets in Chonnam Province for one or two weeks at each dental clinic during year 2006. Results : The third quartile patient surface doses were 2.8 mGy for overall periapical exposures and 3.2 mGy for periapical mandibular molar exposures. Conclusion : The third quartile patient surface doses in Chonnam Province can be used as a guide to accepted clinical practice to reduce patient radiation exposure for the surveyed reference doses were below the recommended dental periapical radiography dose of 7 mGy by IAEA.

• 한국의료질향상학회지
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• 제9권1호
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• pp.90-100
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• 2002

Background : This study was attempted to provide us with basic data on how to environmental improvement with patients for examination, and to offer them better treatment. This study was performed to compare the patients, perception between before and after improvement in the diagnostic radiography room. Methods : The data was collected by interviewing 75 patients who underwent the radiography under the diagnostic radiology at Seoul National University Hospital in Korea. The interview ran from August 9 to October 18, 1999. Data were analyzed by percentage and paired t-test. SD(Semantic Differential) method was composed of adjective 13 words. Results : Patients were attending the elementary schools in the Seoul residents. There was no significant difference in kindness unkindness dimension and were significant differences in other dimensions. The mean score of response level to present room was 3.67 and that of improvement room was 2.16. Conclusions : The results of this study suggest a radiography room plan which is considering emotional aspect of children.

• The Journal of Korean Physical Therapy
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• 제19권3호
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• pp.41-46
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• 2007

Purpose: This study was to investigate how dose the radiography findings are to magnetic resonance (MR) image findings in the L5-S1 instability patients. The subjects of this study were comprised of eleven males and fifteen females, who had Lumbago and agreed with this research. Methods: Radiography and MR images of Lumbar spine were acquired respectively from subjects in conditions of maximum flexion and extension. The horizontal and angular displacements in lumabosacral spine radiography were used to assess the instability of lumbar spine. MR images were also used to evaluate the intervertebral disc abnormalities and change of bone marrow. Results: The results are as follows. 1. In the case of flexion transitional displacement proposed by Dupuis et al, the specificity and negative predictive value were good accuracy ($0.7{\sim}0.8$), and the negative predictive value was in average. In the case of extension displacement, the negative predictive value was about average ($0.6{\sim}0.7$), but the sensitivity, specificity and positive predictive value were below the poor (<0.6). On the other side, the specificity was about average but other things were below in the case of angular displacement. 2. In the case of flexion transitional displacement proposed by Dupuis et al., compared with the intervertebral disc abnormalities, the negative prediction value was excellent, the sensitivity good, and the specificity about average. In the case of extension, the negative prediction value was about average, but the other things were poor. On the other side the specificity and negative predictive value had good accuracy and the sensitivity and positive prediction value were below average in the case of angular displacement. Conclusion: The above results show that the radiography finding is sufficiently helpful to find the lumbar spine instability as an economic point of view.

• 대한방사선기술학회지:방사선기술과학
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• 제42권6호
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• pp.477-482
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• 2019

Recently, due to the increased use of medical radiation, the radiation exposure of radiation workers should be considered as well as medical exposure of patients. And it is recommended to close the door during radiography. however, In this study, when the door was inevitably opened for radiography, the proposed method was to install the shield as a method of reducing the exposure dose. And its efficiency was analyzed. In simple chest radiography, the measurement point was changed according to the measurement location. Dose rate were measured 10 times for each condition using a dosimeter. And the average value was derived. Using this, the change of dose according to the opening and closing of the door and the installation of the shield was analyzed. Using this, we compared and analyzed the dose change according to the door opening and closing and the installation of the shield, and significance was verified through the SPSS ver. 24. Depending on whether the door was opened or closed, 11,215.35%, 159.0%, 101.9% increased in front of the door in the consol room, behind the wall and behind the lead glass. Depending on the installing of the shield, the 49.2%, 29.6%, 19.9%, 30.6% decrease in front of the door in the examination and consol room, behind the wall and lead glass. In addition, statistical analysis was showed that there were significant differences in both the results according to whether the door was opened or closed and shielding(p<.05). Close the door during radiography. However, when the door should be opened, it was confirmed that the dose rate were reduced by installing the shield. Therefore, to optimize radiation protection, it is recommended to install shields when opening the door.

• 한국치위생학회지
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• 제12권5호
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• pp.987-997
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• 2012

Objectives : This study was carried out in order to obtain basic data for students' efficient acquirement and instruction of radiography technology in the future by surveying dental hygiene students' recognition of periapical radiography. Methods : This study carried out a questionnaire survey targeting dental hygiene students from December 2009 to December 2010, and obtained the following results. Results : 1. As a result of examining recognition on periapical radiography, the bisecting angle technique was indicated to be averagely $3.84{\pm}0.566$ points. The paralleling technique was indicated to be $2.66{\pm}0.701$ points. 2. As a result of examining about problems given the bisecting angle technique, what had been most difficult given the bisecting angle technique was indicated to be the highest in cone positioning with 34.2%. The most difficulty given deciding on the X-ray vertical-angel irradiation direction was indicated to be the highest with 66.9% in adjusting the cone direction on the virtual bisector. 3. As a result of examining about problems given the paralleling technique, what had been most difficult in the process of the paralleling technique was indicated to be the highest with 56.7% in fixing the film immobilization device inside the mouth. Conclusions : Examining the above results, it is considered that there is a need of understanding morphological and anatomical structure inside the mouth in order to reduce the mistake rate given the periapical radiography, and that it is important to increase skill level by repetitively shooting several times with having enough time.