• Journal of radiological science and technology
• /
• v.41 no.5
• /
• pp.457-462
• /
• 2018

The purpose of this study was to compare image quality of indirect digital radiography (IDR) system using the International Electro-technical Commission standard (IEC 62220-1), and to suggest the analysis of noise power spectrum (NPS) which were applied to IEC 62220-1 in medical imaging. In this study, Pixium 4600 (Trixell, France) which is indirect flat panel detector (FPD) was used. The size of image receptor (IR) is $7{\times}17$ inch (matrix $3001{\times}3001$) which performed 14bit processing and pixel pitch is $143{\mu}m$. In IEC standard, NPS evaluation were applied to RQA3, RQA5, RQA7 and RQA9. Because of different radiation quality, each region of interesting (ROI) were compared. The results of NPS indicated up to $3.5mm^{-1}$ including low Nyquist frequency. RQA5 indicated the lowest NPS and the others indicated higher NPS results relatively. NPS result of ROI a38 was higher than ROI a92 and this result indicated that there are more noise in left (cathode) than right (anode). This study were to evaluate NPS by using different radiation quality and setting the each ROI, and to suggest the quantitative methods of measuring NPS.

• Journal of Radiation Protection and Research
• /
• v.24 no.3
• /
• pp.161-170
• /
• 1999

System performances in terms of image quality between an amorphous silicon DR system and a conventional film-screen system were evaluated. Various aspects of image quality MTF (modulation transfer function), NPS (noise power spectrum), SNR(signal-to-noise ratio) and contrast were measured and calculated. The MTF of the DR system was comparable to the film-screen systems. The noise was mainly dominated by the quantum mottle in both systems and the electronic noise was found in the DR system. The contrast of the DR system was better than the film-screen systems by virtue of high sensitivity and image processing. Compared to the film-screen systems in general radiography, the DR system had similar resolution and showed better contrast with the same exposure condition after contrast manipulation. The results of this study provide some useful information about the performance of the DR system in connection with medical applications.

• Journal of Dental Anesthesia and Pain Medicine
• /
• v.16 no.2
• /
• pp.103-109
• /
• 2016

Background: One nostril must be selected for nasotracheal intubation. In some cases, structural anomalies within the nasal cavity hinder the insertion of the tube or complications, such as epistaxis, develop. This study examined the possibility of using radiography to select the nostril that would induce fewer complications. Methods: Four hundred and five patients who underwent nasotracheal intubation under general anesthesia were studied. A 7.0-mm internal diameter nasal right angle endotracheal (RAE) tube and 6.5-mm internal diameter nasal RAE tube were inserted into men and women, respectively. Complications were considered to have developed in cases in which insertion of the tube into the nasal cavity failed or epistaxis occurred. The tube was inserted into the other nostril for insertion failures and hemostasis was performed in cases of epistaxis. The degree of nasal septal deviation was determined from posteroanterior skull radiographs or panoramic radiographs; the incidence of complications was compared depending on the direction of the septal deviation and the intubated nostril. Results: The radiographs of 390 patients were readable; 94 had nasal septum deviation. The incidence of complications for cases without nasal septum deviation was 16.9%, that for cases in which the tube was inserted into the nostril on the opposite side of the deviation was 18.5%, and that for cases in which the tube was inserted into the nostril with the deviation was 35.0%, showing a high incidence of complications when intubation is performed through the nostril with septum deviation (chi-square test, P < 0.05 ). Conclusions: Although there were no differences in the incidence rates of complications between intubation through the left nostril and that through the right nostril, radiological findings indicated that incidence of complications significantly increased when the tube was inserted into the nostril with the septum deviation.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.30 no.4
• /
• pp.667-672
• /
• 2003

Rieger syndrome is a rare, autosomal dominant genetic disorder characterized by malformation of the anterior chamber of the eye(goniodysgenesis) coincident with hypodontia. It may also be accompanied by a spectrum of dental, craniofacial and somatic anomalies. Mutations in paired-like homeodomain transcription factor2(PITX2) are associated with the syndrome, and its frequency in the general population has been estimated to be 1 : 200,000. In the present case, the patient, 4 year 7 month-old female, had posterior embryotoxon and polycoria. The maxilla was retrusive in cephalometric radiography. She had congenital missing on #52, #62 and some tooth germs of permanent tooth were not detected in panoramic radiography. The purpose of this paper is to report the dental and craniofacial findings and review the pertinent literature through this case.

• Journal of Radiation Industry
• /
• v.12 no.4
• /
• pp.365-372
• /
• 2018

The use of CT examinations is increasing rapidly and radiation dose from CT examinations is much higher than other diagnostic radiography examinations including general radiography and mammography. DRLs used to optimize the radiation dose of patients by diagnostic radiology in each country. The objective of this study was to investigate and to analyze the status of DRLs from CT examinations in domestic and other countries. In other countries, DRLs were set for each age group and each examination considering the medical situation of each country. In Korea, DRLs were set for adults and children in 2017. For adults, DRLs were set for 13 examinations. Reported DLP values were 1119, 297, $472mGy{\cdot}cm$ for head, chest and abdomen pelvis examination, respectively. For children, DRLs were set for head examinations. Reported DLP values were 298 (0~1 years), 404 (2~5 years), 494 (6~10 years), 1,088 (11~15 years) $mGy{\cdot}cm$. DRLs of Korea were similar to other countries for head examinations. For chest examinations and abdomen pelvis examinations were relatively lower than other countries. As a major reason for relatively low radiation dose, it is considered to contribute the activity and management of medical radiation safety at national level.

• Journal of Dental Anesthesia and Pain Medicine
• /
• v.22 no.6
• /
• pp.427-435
• /
• 2022

Background: This study aimed to investigate the relationship between pharyngeal morphology and the success or failure of blind nasotracheal intubation using standard lateral cephalometric radiography and to analyze the measurement items affecting the difficulty of blind nasotracheal intubation. Methods: Assuming a line perpendicular to the Frankfort horizontal (FH) plane, the reference point (O) was selected 1 cm above the posterior-most end of the hard palate. A line passing through the reference point and parallel to the FH plane is defined as the X-axis, and a line passing through the reference point and perpendicular to the X-axis is defined as the Y-axis. The shortest length between the tip of the uvula and posterior pharyngeal wall (AW), shortest length between the base of the tongue and posterior pharyngeal wall (BW), and width of the glottis (CW) were measured. The midpoints of the lines representing each width are defined as points A, B, and C, and the X and Y coordinates of each point are obtained (AX, BX, CX, AY, BY, and CY). For each measurement, a t-test was performed to compare the tracheal intubation success and failure groups. A binomial logistic regression analysis was performed using clinically relevant items. Results: The items significantly affecting the success rate of blind nasotracheal intubation included the difference in X coordinates at points A and C (Odds ratio, 0.714; P-value, 0.024) and the ∠ABC (Odds ratio, 1.178; P-value, 0.016). Conclusion: Using binomial logistic regression analysis, we observed statistically significant differences in AX-CX and ∠ABC between the success group and the failure group.

• Journal of Veterinary Clinics
• /
• v.40 no.2
• /
• pp.135-138
• /
• 2023

A one-month-old Thoroughbred colt presented with left hindlimb lameness grade 5/5, according to the American Association of Equine Practitioners' lameness scale. The colt started showing signs of lameness two weeks earlier without being involved in an accident. A local veterinarian examined the foal; radiography revealed no significant findings under the hip joint. No improvement was noted after 15 days of non-steroidal anti-inflammatory drugs (NSAIDs) medication. On presentation at our hospital, ultrasonography was performed, which revealed no significant findings in the iliac wings. The foal underwent a computed tomography (CT) scan under general anesthesia. CT revealed bone cysts in the following that could have caused the lameness: the left transverse process of the 5th, 6th lumbar, and the 1st sacrum vertebrae; osteophytes in the auricular surface of the ilium, suggestive of sacroiliac arthritis. The foal recovered smoothly from anesthesia with assistance. The foal was treated with NSAIDs and rested for more than six months. The owner reported that the foal showed no lameness one year later. CT revealed bony changes in the lumbosacral region that were not detected by radiography and ultrasonography, suggesting that CT could be useful for detecting abnormalities in the pelvic region of horses.

• Tuberculosis and Respiratory Diseases
• /
• v.86 no.3
• /
• pp.226-233
• /
• 2023

Background: Inactive or old, healed tuberculosis (TB) on chest radiograph (CR) is often found in high TB incidence countries, and to avoid unnecessary evaluation and medication, differentiation from active TB is important. This study develops a deep learning (DL) model to estimate activity in a single chest radiographic analysis. Methods: A total of 3,824 active TB CRs from 511 individuals and 2,277 inactive TB CRs from 558 individuals were retrospectively collected. A pretrained convolutional neural network was fine-tuned to classify active and inactive TB. The model was pretrained with 8,964 pneumonia and 8,525 normal cases from the National Institute of Health (NIH) dataset. During the pretraining phase, the DL model learns the following tasks: pneumonia vs. normal, pneumonia vs. active TB, and active TB vs. normal. The performance of the DL model was validated using three external datasets. Receiver operating characteristic analyses were performed to evaluate the diagnostic performance to determine active TB by DL model and radiologists. Sensitivities and specificities for determining active TB were evaluated for both the DL model and radiologists. Results: The performance of the DL model showed area under the curve (AUC) values of 0.980 in internal validation, and 0.815 and 0.887 in external validation. The AUC values for the DL model, thoracic radiologist, and general radiologist, evaluated using one of the external validation datasets, were 0.815, 0.871, and 0.811, respectively. Conclusion: This DL-based algorithm showed potential as an effective diagnostic tool to identify TB activity, and could be useful for the follow-up of patients with inactive TB in high TB burden countries.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
• /
• v.27 no.2
• /
• pp.49-61
• /
• 1997

The purpose of this study was to compare E-speed film, CDR, and modified CDR images by means of observing some artificial defects of alveolar bone wall in the sound human dried mandibles. High diagnostic accuracy was shown in 1 wall and 4 wall defects by all 5 observers (2 Radiologists, 2 Periodontists, 1 General practitioner), but the diagnosis in 2 wall and 3 wall defects was inaccurate. Modified CDR images had the more diagnostic accuracy than E-speed film and CDR images, but there was no statistical difference among them. Finally, radiologist used modified CDR images more than others and used equalization effect more than the change in contrast and/or brightness.

• Journal of Chest Surgery
• /
• v.35 no.12
• /
• pp.906-908
• /
• 2002

A 60-year-old male was admitted to our hospital complaining of general weakness. Chest radiography showed lung mass on left lower lobe. After left lower lobectomy and mediastinal lymph node dissection, The mass was pathologically diagnosed as large cell neuroendocrine carcinoma. Pulmonary large cell neuroendocrine carcinoma is rare. Herein we report a case of large cell neuroendocrine carcinoma in lung.