PURPOSE: The incidence of multiple trauma is increasing nowadays and is the leading cause of death among young adults. Initial treatment is well known to be crucial in multiple trauma victims. However, many indiscriminate transfers occur due to the lack of a well-organized trauma system in Korea. The objective of this study is to demonstrate the current serious state in which major trauma patients are transferred to the Emergency Medical Center of a university hospital from another medical center. METHODS: From November 2009 to October 2010, we performed a retrospective study to analyze the characteristics of patients who visited the Ajou University Medical Center located in Gyeonggi-do. We evaluated the ISS (injury severity score), and a score over 15 point was identified as major trauma. The major trauma patients were separated into two groups according to the visit route, and the characteristics of each group were analyzed. RESULTS: Among the 88,862 patients who visited to the Emergency Medical Center, trauma patients accounted for 19,950, and 343 of them were evaluated as major trauma patients. Among the 343 patients, 170 patients had been transferred from other medical centers. The proportion of males to females was 3.3:1, and the mean ISS was 22.7. The leading cause of trauma was motor vehicle accidents. Of the total 170 patients, 77.6% were admitted to the Intensive care unit and 36.3% underwent surgery. The 170 patients that had been transferred to our medical center, 78.8% were transferred from Gyeonggi-do, 15.3% were transferred from other regions, and 5.9% were miscellaneous. CONCLUSION: Almost half of the major trauma victims treat at our medical center had been transferred from other medical centers. Establishing a traumatic system, supported by well-organized trauma centers and emergency medical services, that can reduce inappropriate transfers among medical facilities is essential.
Academic Medical Centers ; Cause of Death ; Emergencies ; Emergency Medical Services ; Female ; Humans ; Incidence ; Injury Severity Score ; Intensive Care Units ; Korea ; Male ; Motor Vehicles ; Multiple Trauma ; Retrospective Studies ; Trauma Centers ; Young Adult

PURPOSE: To evaluate the CT features of abdominal tuberculosis by the pattern anaylsis. MATERIALS AND METHODS: We retrosepctively reviewed the CT findings of confirmed abdominal tuberculosis in 16 patients. Of the 16 patients, 1 was man and the remaining 15 were women with an average age of 34.1 years and the highest incidence in the twenties of age. Intravenous and oral contrast agents were used in all patients. The amount and location of ascites and the changes in the omenturn, mesentery, bowel wall, and peritoneum were analyzed. The morphologic feature, size and main compartment of involvement were also evaluated in the cases with lymphadenopathy as well as other changes in intraabdominal organs. RESULTS: The abdominal tuberculosis was more common in the female(15/16, 93.8%) and could be classified into 3 patterns on their CT findings;Complex ascitic, lymphadenopathy, or abscess forms. The complex ascitic form(10/16, 62.5%) was most commonly seen and characterized by uneven distribution and Ioculation of intraperitoneal fluid collection and marked changes of the omenturn and mesentery. The lymphadenopathy form(3/16, 18.8%) was characterized by central low density and peripheral rim enhancement on postcontrast CT with common involvements of porta hepatis and upper abdominal and paraaortic lymph nodes. The abscess form(3/16, 18.8%) was mainly related to the pelvic abscesses. CONCLUSION: CT was valuable in analyzing the patterns of the lesions and making a diagnosis of abdominal tuberculosis.
Abscess ; Ascites ; Contrast Media ; Diagnosis ; Female ; Humans ; Incidence ; Lymph Nodes ; Lymphatic Diseases ; Mesentery ; Peritoneum ; Tuberculosis*

No abstract available.
Transplantation* ; Tuberculosis*

No abstract available.
Transplantation* ; Tuberculosis*

Purpose: This study aimed to investigate the computed tomography and magnetic resonance imaging features of giant cell tumors in the temporomandibular joint region to facilitate accurate diagnoses. Materials and Methods: From October 2007 to June 2020, 6 patients (2 men and 4 women) at Yonsei University Dental Hospital had histopathologically proven giant cell tumors in the temporomandibular joint. Their computed tomography and magnetic resonance imaging findings were reviewed retrospectively, and the cases were classified into 3 types based on the tumor center and growth pattern observed on the radiologic findings. Results: The age of the 6 patients ranged from 25 to 53 years. Trismus was found in 5 of the 6 cases. One case recurred. The mean size of the tumors, defined based on their greatest diameter, was 32 mm (range, 15–41 mm). The characteristic features of all cases were a heterogeneously-enhancing tumorous mass with a lobulated margin on computed tomographic images and internal multiplicity of signal intensity on T2-weighted magnetic resonance images. According to the site of origin, 3 tumors were bone-centered, 2 were soft tissue-centered, and 1 was peri-articular. Conclusion Computed tomography and magnetic resonance imaging yielded a tripartite classification of giant cell tumors of the temporomandibular joint according to their location on imaging. This study could help clinicians in the differential diagnosis of giant cell tumors and assist in proper treatment planning for tumorous diseases of the temporomandibular joint.

Purpose: This study aimed to compare the therapeutic effects of corticosteroid irrigations and normal saline irrigations in the early inflammatory state of the salivary gland. Materials and Methods: Adult male Wistar rats were divided into experimental (n=6) and control (n=3) groups. Inflammation was induced in the experimental subjects on both sides of the submandibular gland with ligation. After 14 days, both sides of the glands were de-ligated and retroductal irrigation using saline (n=3) and a corticosteroid (n=3) was performed on the left sides only. The controls (n=3) were used to normalize the gland state for the effects of diet and aging. Magnetic resonance imaging was performed to confirm inflammation and post-irrigation gland recovery by measuring relative signal intensity (SI). The glands were excised for histological examination. Results: All experimental animals showed inflamed glands with increased SI and subsequent recovery of the gland with decreased SI to varying degrees. The SI of the controls showed no significant changes during the overall period. The mean SI change of the irrigated gland was higher than that of the non-irrigated side, without a significant difference. The corticosteroid-irrigated glands showed a greater change in SI than that of the saline-irrigated glands. Histology revealed that inflammation was not observed in most of the irrigated glands, while mild to moderate quantities inflammatory cells were found in non-irrigated glands. Conclusion Corticosteroid irrigation mitigated the early stages of salivary gland inflammation more effectively than normal saline.

Purpose: This study aimed to evaluate the performance of transfer learning in a deep convolutional neural network for classifying implant fixtures. Materials and Methods: Periapical radiographs of implant fixtures obtained using the Superline (Dentium Co. Ltd., Seoul, Korea), TS III (Osstem Implant Co. Ltd., Seoul, Korea), and Bone Level Implant (Institut Straumann AG, Basel, Switzerland) systems were selected from patients who underwent dental implant treatment. All 355 implant fixtures comprised the total dataset and were annotated with the name of the system. The total dataset was split into a training dataset and a test dataset at a ratio of 8 to 2, respectively. YOLOv3 (You Only Look Once version 3, available at https://pjreddie.com/darknet/yolo/), a deep convolutional neural network that has been pretrained with a large image dataset of objects, was used to train the model to classify fixtures in periapical images, in a process called transfer learning. This network was trained with the training dataset for 100, 200, and 300 epochs. Using the test dataset, the performance of the network was evaluated in terms of sensitivity, specificity, and accuracy. Results: When YOLOv3 was trained for 200 epochs, the sensitivity, specificity, accuracy, and confidence score were the highest for all systems, with overall results of 94.4%, 97.9%, 96.7%, and 0.75, respectively. The network showed the best performance in classifying Bone Level Implant fixtures, with 100.0% sensitivity, specificity, and accuracy. Conclusion Through transfer learning, high performance could be achieved with YOLOv3, even using a small amount of data.

Purpose: This study was to investigate the types of imaging modalities, analytical methods for age estimation, and the age of the subjects in research on age estimation using dental radiography through a scoping review, and to investigate the overall trends in age estimation studies. Materials and Methods: A scoping review was designed according to the Arksey and O’Malley guidelines and the Preferred Reporting Items for Systematic Review and Meta-analysis (PRISMA) statement. Three electronic databases were used as search sources (Medline, Embase, and Cochrane Library). Studies were classified according to the three main components of the research question. “What are the imaging modalities, analytical methods, and target age in dental imaging-based age estimation studies?”Result: The final 198 studies were selected by two reviewers. The most common imaging modality used in studies was panoramic radiography (69.7%), and studies using cone-beam computed tomography have increased over time. Analytical methods for age estimation were 62.6% in studies based on tooth development and 26.3% in studies using pulp/tooth ratio. The subject age was 27.8% for children and 27.3% for adults. Studies conducted in all age groups comprised the smallest category (5.2%). Conclusion Panoramic radiography has been the most used types of imaging modalities for age estimation, and the most common analytical method was analysis of tooth development. Most studies targeted specific ages, and very few involved all age groups. Dental age estimation studies should be carried out with appropriate consideration of the imaging modality that is analyzed, the methods that are used, and the age that is targeted.

Purpose: This study proposed a generative adversarial network (GAN) model for T2-weighted image (WI) synthesis from proton density (PD)-WI in a temporomandibular joint (TMJ) magnetic resonance imaging (MRI) protocol. Materials and Methods: From January to November 2019, MRI scans for TMJ were reviewed and 308 imaging sets were collected. For training, 277 pairs of PD- and T2-WI sagittal TMJ images were used. Transfer learning of the pix2pix GAN model was utilized to generate T2-WI from PD-WI. Model performance was evaluated with the structural similarity index map (SSIM) and peak signal-to-noise ratio (PSNR) indices for 31 predicted T2-WI (pT2). The disc position was clinically diagnosed as anterior disc displacement with or without reduction, and joint effusion as present or absent. The true T2-WI-based diagnosis was regarded as the gold standard, to which pT2-based diagnoses were compared using Cohen’s ĸ coefficient. Results: The mean SSIM and PSNR values were 0.4781(±0.0522) and 21.30(±1.51) dB, respectively. The pT2 protocol showed almost perfect agreement (ĸ=0.81) with the gold standard for disc position. The number of discordant cases was higher for normal disc position (17%) than for anterior displacement with reduction (2%) or without reduction (10%). The effusion diagnosis also showed almost perfect agreement (ĸ=0.88), with higher concordance for the presence (85%) than for the absence (77%) of effusion. Conclusion The application of pT2 images for a TMJ MRI protocol useful for diagnosis, although the image quality of pT2 was not fully satisfactory. Further research is expected to enhance pT2 quality.

Purpose: The aim of this study was to investigate the types and frequency of the various incidental findings (IFs) on magnetic resonance images (MRI) taken from the patients with temporomandibular disorder (TMD) symptoms. Materials and Methods: Temporomandibular joint (TMJ) MRI taken from 1,013 patients with TMD symptoms were evaluated retrospectively. IF was defined as imaging features that were accidentally or unexpectedly found, rather than degenerative bony changes of TMJ complex or disc derangement. They were classified into two groups as TMJ site-specific findings and unexpected findings at other regions. The frequency of the sub groups was analyzed.Result: A total of 26 (2.57%) cases with IFs were classified into 13 cases with TMJ site-specific findings and 13 cases with unexpected findings at other region. TMJ site-specific findings included synovial chondromatosis in 6 cases, synovial cyst in 6 cases and osteochondroma in one case. Unexpected findings included salivary gland tumor in 3 cases, developmental cyst in 3 cases, vascular malformation in 2 cases, mastoiditis in 4 cases and sialadenitis on parotid gland in one case. Conclusion When diagnosing TMD through TMJ MRI, clinicians should carefully read the image, considering the possibility of IFs because TMJ MRI can provide pathologic information in TMJ region and other oral and maxillofacial region.