• Journal of radiological science and technology
• /
• v.46 no.6
• /
• pp.501-508
• /
• 2023

This study used a adult absorption dose phantom (CIRS model 701-G, USA) made of human equivalent material and the vascular imaging equipment Allura Xper FD 20 (Philips, Netherlands). Optically stimulated luminescent dosimeters (OSLD) were inserted into the anatomical positions corresponding to each organ, and the exposure dose was measured. Dose area product (DAP) and air kerma (AK) measured by the dose meter in the equipment were compared. Continuous imaging was performed at two angles for a total of 20 minutes, with a frame per seconds of 3.75 and 7.5 fps and an FOV of 42 cm, 37 cm, and 31 cm, respectively, under the conditions of fluoflavor I, II, and III, each selected for 5 repetitions. This study was found that selecting a lower fps was the most effective way to reduce patient exposure dose, and adjusting the fluoflavor was a good alternative method for reducing patient exposure dose at high fps. Therefore the method of condition change with the greatest dose reduction effect is to set the minimum FPS and can reduce patient exposure dose according to geometric conditions and fluoflavor characteristics.

• Journal of radiological science and technology
• /
• v.44 no.4
• /
• pp.315-325
• /
• 2021

The purpose of this study is to investigate the changes in lipid proton (LP) composition according to the induced obese fatty liver and to use it as basic data for treatment and diagnosis of fatty liver in the future. The phantom study was conducted to identify differences between STEAM and PRESS Pulse sequences in LP concentration. A high-fat diet (60%) was administered to eight Sprague-Dawley rats to induce obesity and fatty liver disease. Baseline magnetic resonance imaging /spectroscopy data were obtained prior to the introduction of high-fat diet, and data acquisition experiments were performed after eight weeks using procedures identical to those used for baseline studies. The six lipid proton metabolites were calculated using LCModel software. The correlation between the fat percentage and each LP, revealed that the methylene protons at 1.3 ppm showed the highest positive correlation. The α-methylene protons to carboxyl and diallylic protons showed negative correlation with fat percentage. The methylene proton showed the highest increase in the LP; however, it constituted only 71.86% of the total LP concentration. The methylene proton plays a leading role in fat accumulation in liver parenchyma.

• Journal of radiological science and technology
• /
• v.45 no.1
• /
• pp.19-29
• /
• 2022

The study is conducted with the subjects who have under gone coronary angiography to examine the influential factors for the severity of coronary stenosis. Four indicators related to hypertension, diabetes, dyslipidemia, obesity of metabolic syndrome were used as influential factors. As a result of the study, metabolic syndrome such as diabetes and dyslipidemia had 3.3 times and 7.7 times higher chance to lead to 1VD, respectively. In 2VD, diabetes showed 2.9 times higher risk, and dyslipidemia showed 8.5 times higher risk. In 3VD, diabetes was found to be 5 times higher and dyslipidemia was 17.5 times higher in risk. Therefore, it was confirmed that dyslipidemia showed the highest correlation among metabolic syndromes. According to this study, it was confirmed that dyslipidemia and diabetes were closely related to the influential factors for coronary artery stenosis.

• Journal of radiological science and technology
• /
• v.41 no.5
• /
• pp.505-509
• /
• 2018

VCP (Vocal Cord Paralysis) is rare but one of most serious complications related to endotracheal intubation. This report is a clinical experience of radiography and laryngeal EMG (Electromyography) assessment for the VCP. A 50-year-old woman with hoarseness, which was occurred after urethral diverticulum excision was examined by laryngoscopy. As a result of laryngoscopy, VCP was observed in left side of her vocal cord, and then recurrent laryngeal nerve damage was detected with additional CT (Computed tomography) scan and laryngeal EMG. After that, the vocal cord movement was recovered as normal state with regular conservative treatment for the 6 months.

• Journal of radiological science and technology
• /
• v.43 no.2
• /
• pp.123-128
• /
• 2020

Radiation Following the 2011 Fukushima nuclear accident in Japan, public interest and anxiety about radiation safety increased, and vague anxiety about commonly exposed living radiation was generated. The Atomic Energy Safety Commission has been conducting a survey of processed products that advertise "negative ions" and "far-infrared" emissions under the Living Radiation Safety Management Act. In this study, in-depth analysis was performed from a statistical point of view using the measurement data presented in the Nuclear Safety Committee's actual survey analysis report as secondary data. As a result, there was a statistically significant difference (p<0.005) between latex and civil affairs products. There were also statistically significant differences (p<0.05) in the results of testing whether there were significant differences in the annual exposure dose between groups after categorizing 71 civil products, including radon beds, into bed, bedding, and living and other categories. The correlation analysis results also confirm that, as is commonly known, the annual doses received from processed products are associated with radon derived from U-238 and Th-232.

• Journal of radiological science and technology
• /
• v.41 no.1
• /
• pp.25-31
• /
• 2018

This study aimed to evaluate the range of maximum TE that could measure T2 relaxation time accurately by setting diverse maximum TE with using contrast medium phantoms. Contrast medium phantoms ranging from low to high concentrations were made by using Gadoteridol. The relaxation time and relaxation rate were compared and evaluated by conducting T2 mapping by using reference data based on various TEs and data obtained from different maximum TEs. It was found that accurate T2 relaxation time could be expressed only when the maximum TE over a certain range was used in the section with long T2 relaxation time, such as the low concentration section of saline or gadolinium contrast medium. Therefore, the maximum TE shall be longer than the T2 relation time for accurately maturing the T2 relaxation of a certain tissue or a substance.

• Journal of radiological science and technology
• /
• v.43 no.6
• /
• pp.461-467
• /
• 2020

In the field of nuclear medicine, errors are sometimes generated because the assessment of the uniformity of gamma cameras relies on the naked eye of the evaluator. To minimize these errors, we created an artificial intelligence model based on CNN algorithm and wanted to assess its usefulness. We produced 20,000 normal images and partial cold region images using Python, and conducted artificial intelligence training with Resnet18 models. The training results showed that accuracy, specificity and sensitivity were 95.01%, 92.30%, and 97.73%, respectively. According to the results of the evaluation of the confusion matrix of artificial intelligence and expert groups, artificial intelligence was accuracy, specificity and sensitivity of 94.00%, 91.50%, and 96.80%, respectively, and expert groups was accuracy, specificity and sensitivity of 69.00%, 64.00%, and 74.00%, respectively. The results showed that artificial intelligence was better than expert groups. In addition, by checking together with the radiological technologist and AI, errors that may occur during the quality control process can be reduced, providing a better examination environment for patients, providing convenience to radiologists, and improving work efficiency.

• Journal of Yeungnam Medical Science
• /
• v.39 no.2
• /
• pp.161-167
• /
• 2022

Congenital web formations are extremely rare anomalies of the extrahepatic biliary tree. We herein report a case of common bile duct septum combined with multiple intrahepatic bile duct strictures in a 74-year-old female patient who was successfully treated with radiological intervention. The patient initially visited the hospital because of upper abdominal pain. Imaging studies revealed multifocal strictures with dilatation in both intra- and extrahepatic ducts; the final clinical diagnosis was congenital common bile duct web combined with multiple intrahepatic duct strictures. Surgical treatment was not indicated because multiple biliary strictures were untreatable, and the disease was clinically diagnosed as benign. The multiple strictures were extensively dilated twice through bilateral percutaneous transhepatic biliary drainage (PTBD) for 2 months. After 1 month of observation, PTBD catheters were successfully removed. The patient is doing well at 6 months after completion of the radiological intervention, with the maintenance of normal liver function. Congenital web of the bile duct is very rare, and its treatment may vary depending on the patterns of biliary stenosis. In cases where surgical intervention is not indicated for congenital web and its associated disease, radiological intervention with balloon dilatation can be a viable therapeutic option.

• Progress in Medical Physics
• /
• v.18 no.3
• /
• pp.139-143
• /
• 2007

The purpose of this study was to measure and evaluate radiation dose for MDCT parameters. Patient dose for various combination of MDCT parameters were experimentally measured, using MDCT (GE light speed plus 4 slice, USA), model 2026C electrometer (RADICAL 2026C, USA), standard Polymethylmethacrylate (PMMA) head and body CT dosimetry phantoms. In clinical situations, for a typical abdominal scan performed with MDCT at 120 kVp, 180 mAs, 20 mm collimation, and a pitch of 0.75 $CTDI_w,\;CTDI_{vol}$ were measured as 20.2 mGy, 26.9 mGy, respectively. When scan length is assumed as 271.3 mm, DLP and measured effective dose of the abdominal would be calculated as $729.1\;mGy{\cdot}cm$, 10.9 mSv, respectively.

• International journal of thyroidology
• /
• v.10 no.1
• /
• pp.14-23
• /
• 2017

Background and Objectives: To evaluate and compare the diagnostic performances of grayscale ultrasound (US) and quantitative parameters obtained from texture analysis of grayscale US and elastography images in evaluating patients with diffuse thyroid disease (DTD). Materials and Methods: From September to December 2012, 113 patients (mean age, $43.4{\pm}10.7years$) who had undergone preoperative staging US and elastography were included in this study. Assessment of the thyroid parenchyma for the diagnosis of DTD was made if US features suggestive of DTD were present. Nine histogram parameters were obtained from the grayscale US and elastography images, from which 'grayscale index' and 'elastography index' were calculated. Diagnostic performances of grayscale US, texture analysis using grayscale US and elastography were calculated and compared. Results: Of the 113 patients, 85 (75.2%) patients were negative for DTD and 28 (24.8%) were positive for DTD on pathology. The presence of US features suggestive of DTD showed significantly higher rates of DTD on pathology, 60.7% to 8.2% (p<0.001). Specificity, accuracy, and positive predictive value was highest in US features, 91.8%, 84.1%, and 87.6%, respectively (all ps<0.05). Grayscale index showed higher sensitivity and negative predictive value (NPV) than US features. All diagnostic performances were higher for grayscale index than the elastography index. Area under the curve of US features was the highest, 0.762, but without significant differences to grayscale index or mean of elastography (all ps>0.05). Conclusion: Diagnostic performances were the highest for grayscale US features in diagnosis of DTD. Grayscale index may be used as a complementary tool to US features for improving sensitivity and NPV.