• Imaging Science in Dentistry
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• v.41 no.2
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• pp.59-62
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• 2011

Purpose : This study was performed to evaluate the changes of jaw bone density around the dental implant after placement using computed tomography scan (CT-Scan). Materials and Methods : This retrospective study consisted of 30 patients who had lost 1 posterior tooth in maxilla or mandible and installed dental implant. The patients took CT-Scan before and after implant placement. Hounsfield Unit (HU) was measured around the implants and evaluated the difference of HU before and after implant installation. Results : The mean HU of jaw bone was 542.436 HU and 764.9 HU before and after implant placement, respectively (p<0.05). The means HUs for male were 632.3 HU and 932.2 HU and those for female 478.2 HU and 645.5 HU before and after implant placement, respectively (p<0.05). Also, the jaw bone with lower density needed longer period for implant procedure and the increased change of HU of jaw bone was less in the cases which needed longer period for osseointegration. Conclusion : CT-Scan could be used to assess the change of bone density around dental implants. Bone density around dental implant was increased after placement. The increased rate of bone density could be determined by the quality of jaw bone before implant placement.

• Journal of Trauma and Injury
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• v.33 no.2
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• pp.119-123
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• 2020

The Coronavirus disease 2019 (COVID-19) has rapidly spread across the world and caused a pandemic. It can be transmitted by an infected person or an asymptomatic carrier and is a highly contagious disease. Prevention and early identification of COVID-19 are important to minimize the transmission of COVID-19. Chest computed tomography (CT) has a high sensitivity for detecting COVID-19, but relatively low specificity. Therefore, chest CT may be difficult to distinguish COVID-19 findings from those of other infectious (notably viral types of pneumonia) or noninfectious disease. Pulmonary contusion has also a lot of similarities on chest CT with COVID-19 pneumonia. We present trauma patients with pulmonary contusion whose CT scans showed findings similar to those of COVID-19, and we report our experience in the management of trauma patients during the COVID-19 pandemic.

• Journal of the Korean Data and Information Science Society
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• v.26 no.1
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• pp.179-185
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• 2015

The cost of advanced medical technologies is commonly considered to be a major factor in the overall escalation of expenditures on health. The use of computed tomography (CT) scanning has increased dramatically over the past decade. CT has been rapidly adopted, despite their high cost. The aim of this study is to analysis the increasing factor of the frequency of the CT, using the decision tree model. Finally, we propose the effective policy option of diagnostic imaging technology in Korea.

• Korean Journal of Digital Imaging in Medicine
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• v.10 no.2
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• pp.39-49
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• 2008

Extravasation of contrast material is a not infrequent complication of enhanced imaging studies and large volume extravasation may result in severe damage. Subcutaneous extravasation of the radiographic contrast medium is one of the complications of the contrast medium-enhanced procedures. Automated power injectors enable the contrast material to be delivered at a uniform high-flow-rate and as a nonfragmented bolus, and this is essential for many contrast material enhanced CT(computed tomography) applications. The major risk associated with the use of automated power injectors is the well known complication of contrast material extravasation at the injection site. Automated injection of CT contrast material can produce the compartment syndrome. Selection of the nonionic contrast material after careful evaluation of the intravenous administration site and monitoring of the patient during the use of a mechanical power injector may help minimize or prevent extravasation injuries. Early identification is important and conservative management is effective in most cases. Prevention of these injuries with the education of radiological technologist remains the ultimate aim.

• Journal of Multimedia Information System
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• v.6 no.2
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• pp.67-74
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• 2019

Bone density is one of the factors in the early failure of dental implants and doctors should make a preoperative assessment of jaw bone density using patient's CT data before dental implant surgery in order to find out whether the patient has osteoporosis and osteopenia. The main goal of this study was to propose a method that based on image processing techniques in order to provide accurate information about where to drill and place an abutment screw of implants in the jaw bone for doctors and reduce human activity for the estimation of the local cancellous bone density of mandible using CT data. The experiment was performed on a computed tomography data of the jaw bone of two different individuals. We assumed that the result of the estimation of jaw bone density depends on the angle of drilling and average HU (Hounsfield Unit) values were used to evaluate the quality of local cancellous bone density of mandible. As a result of this study, we have been developed a toolbox that can be used to estimate jaw bone density automatically and found a positive correlation between the angle of the drill and time complexity but a negative correlation between the diameter of the drill and time complexity.

• Journal of Trauma and Injury
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• v.34 no.2
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• pp.112-118
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• 2021

Purpose: Negative laparotomy in patients with abdominal penetrating injuries (APIs) is associated with deleterious outcomes and unnecessary expense; however, the indications for laparotomy in hemodynamically stable patients with ambiguous computed tomography (CT) findings remain unclear. This study aimed to identify the factors associated with negative laparotomy. findings Methods: Data of patients who underwent laparotomy for APIs between 2011 and 2019 were retrospectively reviewed. Patients who presented with definite indications for laparotomy were excluded. The patients were dichotomized into negative and positive laparotomy groups, and the baseline characteristics, laboratory test results, and CT findings were compared between the groups. Results: Of 55 patients with ambiguous CT findings, 38 and 17 patients were assigned to the negative and positive laparotomy groups, respectively. There was no significant difference between the groups with respect to the baseline characteristics or the nature of the ambiguous CT findings. However, the laboratory test results showed that there was a difference in the percentage of neutrophils between the groups (negative: 55.6% [range 47.4-66.1%] vs. positive: 79.8% [range 77.6-88.2%], p<0.001), although the total white blood cell count was not significantly different. The mean duration of hospital stay for the negative laparotomy group was 13.1 days, and seven patients (18.4%) experienced complications. Conclusions: Diagnostic factors definitively indicative of laparotomy were not identified, although the percentage of neutrophils might be helpful. However, routine laparotomy in patients with peritoneal injuries could result in instances of negative laparotomy.

• Journal of Trauma and Injury
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• v.36 no.1
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• pp.8-14
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• 2023

Purpose: The aim of this study was to assess the agreement between intraoperative transcranial sonography (TCS) and postoperative computed tomography (CT) in patients with traumatic brain injuries. Methods: We performed a retrospective cross-sectional study of 35 patients who underwent TCS during surgery, among those who presented to a regional trauma center and underwent decompressive craniectomy between January 1, 2017 and April 30, 2020. Results: The mean difference between TCS and CT in measuring the midline shift was -1.33 mm (95% confidence interval, -2.00 to -0.65; intraclass correlation coefficient [ICC], 0.96; P<0.001). An excellent correlation was found between TCS and CT in assessing contralateral subdural hematomas (ICC, 0.96; P<0.001) and focal hematoma lesions (ICC, 0.99; P<0.001). A very good correlation between TCS and CT was found for measurements of ventricle width (ICC, 0.92; P<0.001). Conclusions: TCS during surgery is considered an effective diagnostic tool for the detection of intraoperative parenchymal changes in patients with traumatic brain injuries.

• Journal of radiological science and technology
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• v.46 no.2
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• pp.107-114
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• 2023

The purpose of this study was to compare the basic radiological characteristics of in-house polymer gel and commercially-available gel (BANG^TM) gel dosimeters with a spectro-photometer to use a optical computed tomography (CT) scanner. We investigated the radiological characteristics including dose linearity, absorbance spectrum, dose rate dependency and inter-and intra-reproducibility at wavelengths of 590, 600 and 630 nm. The optimal dose linearities of two gel dosimeters showed R² value of 0.939 and 0.948 at wavelengths of 590 nm and 600 nm, respectively. For two polymer gel dosimeters, there is no peak sensitivity within the range of all wavelengths in absorbance spectrum. For in-house gel dosimeter, the dose rate dependency were within 5% for all wavelengths except for the dose rate of 100 MU/min. For BANG^TM gel dosimeter, the dose rate dependency showed an error range of ±5% for all wavelengths. The inter-and intra-reproducibility of two gel dosimeters were within the range of 2.5%. We have confirmed that the two gel dosimeters was appropriate for use with a optical CT scanner.

• Journal of dental hygiene science
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• v.23 no.1
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• pp.60-67
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• 2023

Background: In our study, a silver diamine fluoride (SDF) compound for the treatment of dental caries was synthesized to characterize its remineralization activity upon direct application to deciduous teeth. This study aimed to use microscopic computed tomography (microCT) and nanoindentation to evaluate whether SDF composite application could effectively arrest dental caries in five exfoliated primary molars. Methods: Carious teeth were extracted and visually examined using quantitative photofluorescence devices (Qraycam and QraypenTM). After performing microCT, the SDF composite was applied to the teeth according to the manufacturer's instructions. The researchers exchanged and precipitated the irritant saliva once daily for 1 week. The teeth were sectioned longitudinally through the centers of the mesial and distal surfaces, embedded, polished, and measured using nanoindentation. Thereafter, microCT was repeated. Statistical analyses were performed using GraphPad Prism software. Results: Following SDF composite application, a remineralized layer was observed on microCT images, and the hardness increased when measured using nanoindentation. We found that demineralized enamel presented with an increased number of irregular crystals in the deep carious lesion group compared with those in the shallow carious lesion group, resulting in a rougher surface. Conclusion: The SDF composite may be used for remineralization of early caries and cessation of advanced caries in primary molars.

• Journal of Trauma and Injury
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• v.28 no.3
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• pp.149-157
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• 2015

Purpose: Traumatic brain injury (TBI) is the most common cause of pediatric trauma patients came to the emergency department. Without guidelines, many of these children underwent repeat brain computed tomography (CT). The purpose of this study was to evaluate the value of repeat brain CT in children with TBI. Methods: We conducted a retrospective study of TBI in children younger than 19 years of age who visited the emergency department (ED) from January 2011 to December 2012. According to the Glasgow Coma Scale (GCS) and Pediatric Glasgow Coma Scale score of the patients, study population divided in three groups. Clinical data collected included age, mechanism of injury, type of TBI, and outcome. Results: A Total 83 children with TBI received repeat brain CT. There were no need for neurosurgical intervention in mild TBI (GCS score 13-15) group who underwent routine repeat CT. 4 patients of mild TBI group, received repeat brain CT due to neurological deterioration, and one patient underwent neurosurgical intervention. Routine repeat CT identified 12 patients with radiographic progression. One patient underwent neurosurgical intervention based on the second brain CT finding, who belonged to the moderate TBI (GCS score 9-12) group. Conclusion: Our study showed that children with mild TBI can be observed without repeat brain CT when there is no evidence of neurologic deterioration. Further study is needed for establish indication for repetition of CT scan in order to avoid unnecessary radiation exposure of children.