• Journal of the Korean Society of Radiology
• /
• v.15 no.2
• /
• pp.159-164
• /
• 2021

The examination using diagnostic x-ray equipment is one of the most useful diagnostic equipment for identifying information in the human body in diagnostic radiology. For this reason, the number of examinations has recently increased a lot. Increasing the number of examinations will accelerate the aging of the device. In addition, this makes them aware of the importance of quality control for the diagnostic x-ray device. Particularly, in a diagnostic x-ray device, quality control refers to an act of always maintaining a certain level of image quality by identifying and correcting all problems that may lead to reduction of the diagnosis area in advance. Therefore, this study summarizes and reports general information about quality control in examinations using diagnostic x-ray equipment.

• Imaging Science in Dentistry
• /
• v.44 no.1
• /
• pp.31-35
• /
• 2014

Purpose: This study was performed to investigate the effect of image enhancement of periapical radiographs according to the diagnostic task. Materials and Methods: Eighty digital intraoral radiographs were obtained from patients and classified into four groups according to the diagnostic tasks of dental caries, periodontal diseases, periapical lesions, and endodontic files. All images were enhanced differently by using five processing techniques. Three radiologists blindly compared the subjective image quality of the original images and the processed images using a 5-point scale. Results: There were significant differences between the image quality of the processed images and that of the original images (P< 0.01) in all the diagnostic task groups. Processing techniques showed significantly different efficacy according to the diagnostic task (P< 0.01). Conclusion: Image enhancement affects the image quality differently depending on the diagnostic task. And the use of optimal parameters is important for each diagnostic task.

• Imaging Science in Dentistry
• /
• v.46 no.4
• /
• pp.245-249
• /
• 2016

Purpose: This study was designed to evaluate differences in the required visibility of anatomic structures according to the diagnostic tasks of implant planning and periapical diagnosis. Materials and Methods: Images of a real skull phantom were acquired under 24 combinations of different exposure conditions in a cone-beam computed tomography scanner (60, 70, 80, 90, 100, and 110 kV and 4, 6, 8, and 10 mA). Five radiologists evaluated the visibility of anatomic structures and the image quality for diagnostic tasks using a 6-point scale. results: The visibility of the periodontal ligament space showed the closest association with the ability to use an image for periapical diagnosis in both jaws. The visibility of the sinus floor and canal wall showed the closest association with the ability to use an image for implant planning. Variations in tube voltage were associated with significant differences in image quality for all diagnostic tasks. However, tube current did not show significant associations with the ability to use an image for implant planning. conclusion: The required visibility of anatomic structures varied depending on the diagnostic task. Tube voltage was a more important exposure parameter for image quality than tube current. Different settings should be used for optimization and image quality evaluation depending on the diagnostic task.

• Korean Journal of Radiology
• /
• v.24 no.10
• /
• pp.1006-1016
• /
• 2023

Objective: Computed tomography (CT) is an established method for the diagnosis, staging, and treatment of multiple myeloma. Here, we investigated the potential of photon-counting detector computed tomography (PCD-CT) in terms of image quality, diagnostic confidence, and radiation dose compared with energy-integrating detector CT (EID-CT). Materials and Methods: In this prospective study, patients with known multiple myeloma underwent clinically indicated whole-body PCD-CT. The image quality of PCD-CT was assessed qualitatively by three independent radiologists for overall image quality, edge sharpness, image noise, lesion conspicuity, and diagnostic confidence using a 5-point Likert scale (5 = excellent), and quantitatively for signal homogeneity using the coefficient of variation (CV) of Hounsfield Units (HU) values and modulation transfer function (MTF) via the full width at half maximum (FWHM) in the frequency space. The results were compared with those of the current clinical standard EID-CT protocols as controls. Additionally, the radiation dose (CTDIvol) was determined. Results: We enrolled 35 patients with multiple myeloma (mean age 69.8 ± 9.1 years; 18 [51%] males). Qualitative image analysis revealed superior scores (median [interquartile range]) for PCD-CT regarding overall image quality (4.0 [4.0-5.0] vs. 4.0 [3.0-4.0]), edge sharpness (4.0 [4.0-5.0] vs. 4.0 [3.0-4.0]), image noise (4.0 [4.0-4.0] vs. 3.0 [3.0-4.0]), lesion conspicuity (4.0 [4.0-5.0] vs. 4.0 [3.0-4.0]), and diagnostic confidence (4.0 [4.0-5.0] vs. 4.0 [3.0-4.0]) compared with EID-CT (P ≤ 0.004). In quantitative image analyses, PCD-CT compared with EID-CT revealed a substantially lower FWHM (2.89 vs. 25.68 cy/pixel) and a significantly more homogeneous signal (mean CV ± standard deviation [SD], 0.99 ± 0.65 vs. 1.66 ± 0.5; P < 0.001) at a significantly lower radiation dose (mean CTDIvol ± SD, 3.33 ± 0.82 vs. 7.19 ± 3.57 mGy; P < 0.001). Conclusion: Whole-body PCD-CT provides significantly higher subjective and objective image quality at significantly reduced radiation doses than the current clinical standard EID-CT protocols, along with readily available multi-spectral data, facilitating the potential for further advanced post-processing.

• Journal of The Korean Radiological Technologist Association
• /
• v.28 no.1
• /
• pp.120-144
• /
• 2002

Purpose The quality assurance in a computed tomography gives a definition to be all the activity so as to optimize the performance of the device and keep an invariable quality of image, and it is to raise a high diagnostic efficiency to obtain a much info

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2008.06a
• /
• pp.499-499
• /
• 2008

High voltage transformer of Diagnostic X-ray system has been contributed to wiping out disease to get a good quality images from patients. High voltage transformer of diagnostic X-ray system has been usefully used for diagnostic purpose but if high voltage transformer performances are deteriorated, low quality image will be archived. In this case, operator has to exposure to get a more good quality images. In this case, unexpected radiation could be exposed to patient and it is very harmful to the patient. And I would like to design and make equipment to checkable high voltage transformer performance after that I wish to test and study what it is most influences in radiation output quality.

• Journal of Korean Society for Quality Management
• /
• v.23 no.4
• /
• pp.58-63
• /
• 1995

To access the quality of a fit to a set of data it is always useful to conduct a posteriori analysis involving the examination of residuals, detection of influential data values, etc. Smoothing splines are a type of nonparametric regression estimators for the diagnostic problem. And leverage value, Cook's distance, and DFFITS are used for detecting influential data. Since high leverage points will always have small residuals, the new diagnostic measures including of properties of leverage and residuals are needed. In this paper, we propose FVARATIO version as diagnostic measure in nonparametric regression. Also we consider the rough bound as analogy with linear regression case.

• Korean Journal of Childcare and Education
• /
• v.20 no.2
• /
• pp.105-126
• /
• 2024

Objective: The study aimed to develop and validate a tool for assessing daycare center organizational competence and for autonomously managing childcare quality. Methods: Through literature review and expert reviews, items were derived and validated using the Content Validity Index. Data from a survey involving 216 directors and 509 teachers were analyzed using SPSS and AMOS to assess reliability and conduct confirmatory factor analysis. Results: Results revealed a 36-item diagnostic tool across four subcategories: shared values (6 items), training abilities (18 items), environmental support (6 items), and organizational promotion (6 items). A diagnostic tool named S.T.E.P+ was developed, named after the first letters of the four subfactors. Skewness and kurtosis were within normality assumptions. Good fit indices (CFI, TLI) and low SRMR and RMSEA values indicated a satisfactory model fit. Cronbach's α values showed high reliability for all factors. The tool enables autonomous diagnosis of childcare quality. Conclusion/Implications: This tool can effectively autonomously diagnose whether a daycare center is providing quality childcare.

• Korean Journal of Radiology
• /
• v.22 no.6
• /
• pp.944-950
• /
• 2021

Objective: To demonstrate the feasibility of percutaneous microwave ablation in desmoid fibromatosis with respect to tumor volume control and improvement in the quality of life. Materials and Methods: Twelve microwave ablations were performed in 9 patients with a histological diagnosis of desmoid fibromatosis between January 2010 and January 2019. The study population included 6 female and 3 male, with an age range of 21-76 years (mean = 46.6 years; standard deviation [SD] = 19.3 years). The mean major axis of the tumors was 10.9 cm (SD = 5.2 cm) and mean lesion volume was 212.7 cm³ (SD = 213 cm³). Their anatomical distribution was as follows: 3 lesions in the thigh, 2 in the gluteus, 2 in the leg and 2 in the periscapular region. We evaluated the reduction in tumor volume and improvement in the quality of life based on the Eastern Cooperative Oncology Group (ECOG) scale. Results: An average tumor volume reduction of 70.4% (SD = 24.9) was achieved, while the quality of life (ECOG scale) improved in 88.9% of patients. Conclusion: Percutaneous microwave ablation may potentially be a safe, effective, and promising technique for controlling tumor volume and improving the quality of life in patients with desmoid fibromatosis.

• The Korean Journal of Cytopathology
• /
• v.19 no.2
• /
• pp.65-71
• /
• 2008

In Korea, the quality control(QC) program forcytopathology was introduced in 1995. The program consists of a checklist for the cytolopathology departments, analysis data on all the participating institutions' QC data, including the annual data on cytologic examinations, the distribution of the gynecological cytologic diagnoses, as based on The Bethesda System 2001, and the data on cytologic-histolgical correlation of the gynecological field, and an evaluation for diagnostic accuracy. The diagnostic accuracy program has been performed 3 times per year with using gynecological, body fluid and fine needle aspiration cytologic slides. We report here on the institutional QC data and the evaluation for diagnostic accuracy since 2004, and also on the new strategy for quality control and assurance in the cytologic field. The diagnostic accuracy results of both the participating institutions and the QC committee were as follows; Category 0 and A: about 94%, Category B: 4-5%, Category C: less than 2%. As a whole, the cytologic daignostic accuracy is relatively satisfactory. In 2008, on site evaluation for pathology and cytology laboratories, as based on the "Quality Assurance Program for Pathology Services" is now going on, and a new method using virtual slides or image files for determining the diagnostic accuracy will be performed in November 2008.