Epidemiological and Clinical Characteristics of Pediatric COVID-19 in the Tertiary Care System in Thailand: Comparative Delta and pre-Delta Era.

Background: Few studies had focused on the epidemiological and clinical characteristics of pediatric COVID-19 (SARS-CoV-2) during Delta and pre-Delta eras in Asia, despite it being a pandemic. Objective: To study the epidemiological and clinical characteristics of three waves of pediatric COVID-19 infections in a tertiary-care setting in Thailand. Methods: This retrospective study reviewed all PCR-confirmed pediatric (0-18 years of age) COVID-19 infections between January 13, 2020, and October 31, 2021, in a tertiary care system in Thailand. Results: 1,019 patients, aged 0.02 - 18 years, 552 (54.2%) male, and 467 (45.8%) female, with a median age of 9.2 years, were enrolled. Asymptomatic cases accounted for 35.7%, of which 106 (18.9%) had abnormal chest X-ray findings. Most cases were classified as having mild clinical symptoms, with only 8 (0.8%) and 4 (0.4%) developing a severe and critical illness, respectively. There were no deaths. The Delta variant appeared more transmissible than previous ones, but we did not see any difference in disease severity. Upper respiratory tract symptoms were predominant, while few cases had lower respiratory tract involvement. The sensitivity and specificity of dyspnea symptoms to predict radiologically confirmed pneumonia were 14% and 95%, respectively, with a likelihood ratio of 3.37. The overall prognosis was good, with only 13 (1.3 %) needing respiratory support. All cases showed clinical improvement with a decent recovery. Conclusion: Pediatric COVID-19 during the Delta variant predominance era generally appeared more transmissible but benign. One-fifth of cases had pneumonia, but few cases needed respiratory support. Prevention remains important for disease control.

Image Quality Evaluation of a Digital Radiography System Made in Thailand.

BACKGROUND: The National Science and Technology Development Agency (NSTDA) in Thailand researched and prototyped digital radiography systems under the brand name BodiiRay aiming for sustainable development and affordability of medical imaging technology. The image restoration and enhancement were implemented for the systems. PURPOSE: The image quality of the systems was evaluated using images from phantoms and from healthy volunteers. METHODS: The survey phantom images from BodiiRay and other two commercial systems using the exposure settings for the chest, the abdomen, and the extremity were evaluated by three experience observers in terms of the high-contrast image resolution, the low-contrast image detectability, and the grayscale differentiation. The volunteer images of the chests, the abdomens, and the extremities from BodiiRay were evaluated by three specialized radiologists based on visual grading on 5-point scaled questionnaires for the anatomy visibility, the image quality satisfaction, and the diagnosis confidence in using the images. RESULTS: BodiiRay phantom results were similar to those from the commercial systems. The overall performance averaged across the exposure settings showed that BodiiRay was slightly better than Fujifilm FDR Go in the low-contrast detectability (p = 0.033) and in the grayscale differentiation (p = 0.004). It was also slightly better than Siemens YSIO Max in the high-contrast resolution (p = 0.018). The images of chest, pelvis, and hand phantoms illustrated comparable visual quality. For volunteer images, the percentage of the images scored ≥4 ranged from 61% to 99%, 23% to 92%, and 96% to 99% for the chest, abdomen, and extremity images, respectively. The average score ranged from 3.63 to 4.46, 3.18 to 4.21, and 4.41 to 4.51 for the chest, abdomen, and extremity images, respectively. CONCLUSION: The phantom image results showed the comparability of these systems. The clinical evaluation showed BodiiRay images provided sufficient image qualities for digital radiography of these body parts.

Methods for the segmentation and classification of breast ultrasound images: a review.

PURPOSE: Breast ultrasound (BUS) is one of the imaging modalities for the diagnosis and treatment of breast cancer. However, the segmentation and classification of BUS images is a challenging task. In recent years, several methods for segmenting and classifying BUS images have been studied. These methods use BUS datasets for evaluation. In addition, semantic segmentation algorithms have gained prominence for segmenting medical images. METHODS: In this paper, we examined different methods for segmenting and classifying BUS images. Popular datasets used to evaluate BUS images and semantic segmentation algorithms were examined. Several segmentation and classification papers were selected for analysis and review. Both conventional and semantic methods for BUS segmentation were reviewed. RESULTS: Commonly used methods for BUS segmentation were depicted in a graphical representation, while other conventional methods for segmentation were equally elucidated. CONCLUSIONS: We presented a review of the segmentation and classification methods for tumours detected in BUS images. This review paper selected old and recent studies on segmenting and classifying tumours in BUS images.

Initialization of active contours for segmentation of breast cancer via fusion of ultrasound, Doppler, and elasticity images.

Active contours (snakes) are an efficient method for segmentation of ultrasound (US) images of breast cancer. However, the method produces inaccurate results if the seeds are initialized improperly (far from the true boundaries and close to the false boundaries). Therefore, we propose a novel initialization method based on the fusion of a conventional US image with elasticity and Doppler images. The proposed fusion method (FM) has been tested against four state-of-the-art initialization methods on 90 ultrasound images from a database collected by the Thammasat University Hospital of Thailand. The ground truth was hand-drawn by three leading radiologists of the hospital. The reference methods are: center of divergence (CoD), force field segmentation (FFS), Poisson Inverse Gradient Vector Flow (PIG), and quasi-automated initialization (QAI). A variety of numerical tests proves the advantages of the FM. For the raw US images, the percentage of correctly initialized contours is: FM-94.2%, CoD-0%, FFS-0%, PIG-26.7%, QAI-42.2%. The percentage of correctly segmented tumors is FM-84.4%, CoD-0%, FFS-0%, PIG-16.67%, QAI-22.44%. For reduced field of view US images, the percentage of correctly initialized contours is: FM-94.2%, CoD-0%, FFS-0%, PIG-65.6%, QAI-67.8%. The correctly segmented tumors are FM-88.9%, CoD-0%, FFS-0%, PIG-48.9%, QAI-44.5%. The accuracy, in terms of the average Hausdorff distance, is respectively 2.29 pixels, 33.81, 34.71, 7.7, and 8.4, whereas in terms of the Jaccard index, it is 0.9, 0.18, 0.19, 0.63, and 0.48.

Pathophysiology of acute middle cerebral artery infarct by multimodal computed tomography: A pilot study in Thai patients.

AIMS: The purpose of this study was to study pathophysiology of acute middle cerebral artery infarct using multimodal CT and to evaluate the safety and feasibility of this method in our center. MATERIALS AND METHODS: Patients who had moderate to severe stroke (NIHSS score > 10), suspected of anterior circulation infarct and presented within 4 hours after stroke onset were prospectively included. Multimodal CTs, using low-osmolar contrast agents, were performed in all patients. RESULTS: Twenty-two patients were included. Mean NIHSS was 16. All patients received intravenous thrombolysis. Favorable outcome was found in nine patients (41%). CTP was unable to identify ischemic lesions in three patients with small subcortical infarct. Most patients (82%) with large middle cerebral artery infarct still had some salvageable brain (penumbra) which partly recovered in a follow-up imaging. Eleven patients (50%) had major artery occlusion. Two patients had creatinine rising within 72 hours. CONCLUSIONS: Multimodal CT does provide information about status of major artery and the volume of salvageable/infarct brain tissue and is safely and easily applicable in our center.

Lymphangioma of the small bowel mesentery: a case report and review of the literature.

Lymphangioma is a rare benign condition characterized by proliferation of lymphatic spaces. It is usually found in the head and neck of affected children. Lymphangioma of the small-bowel mesentery is rare, having been reported for less than 1% of all lymphangiomas. Importantly, it can cause fatal complications such as volvulus or involvement of the main branch of the mesenteric arteries, requiring emergency surgery. Moreover, the gross and histopathologic findings may resemble benign multicystic mesothelioma and lymphangiomyoma. Immunohistochemical study for factor VIII-related antigen, D2-40, calretinin and human melanoma black-45 (HMB-45) are essential for diagnosis. Factor VIII-related antigen and D2-40 are positive in lymphangioma but negative in benign multicystic mesothelioma. HMB-45 shows positive study in the smooth-muscle cells around the lymphatic spaces of the lymphangiomyoma. We report a case of small-bowel volvulus induced by mesenteric lymphangioma in a 2-year-and-9-mo-old boy who presented with rapid abdominal distension and vomiting. The abdominal computed tomography scan showed a multiseptated mass at the right lower quadrant with a whirl-like small-bowel dilatation, suggestive of a mesenteric cyst with midgut volvulus. The intraoperative findings revealed a huge, lobulated, yellowish pink, cystic mass measuring 20 cm × 20 cm × 10 cm, that was originated from the small bowel mesentery with small-bowel volvulus and small-bowel dilatation. Cut surface of the mass revealed multicystic spaces containing a milky white fluid. The patient underwent tumor removal with small-bowel resection and end-to-end anastomosis. Microscopic examination revealed that the cystic walls were lined with flat endothelial cells and comprised of smooth muscle in the walls. The flat endothelial cells were positive for factor VIII-related antigen and D2-40 but negative for calretinin. HMB-45 showed negative study in the smooth-muscle cells around the lymphatic spaces. Thus, the diagnosis was lymphangioma of the small bowel mesentery with associated small bowel volvulus.

Pediatric acute and chronic rhinosinusitis: comparison of clinical characteristics and outcome of treatment.

BACKGROUND: Rhinosinusitis (RS) is a common problem in children. There are very few published studies comparing acute rhinosinusitis (ARS) and chronic rhinosinusitis (CRS) in children. OBJECTIVE: To determine the clinical manifestations in children with ARS and CRS. METHODS: One hundred and fifty-four patients with a clinical diagnosis of RS were enrolled. ARS was defined as persistent symptoms for more than 10 days but less than 4 weeks and CRS was defined as persistent symptoms for longer than 8 weeks. Patients were interviewed to obtain demographic and clinical data. Physical findings and medications were recorded. All patients underwent radiographic studies. Allergy and immunological testing were done in selected case. All data were compared between the ARS and CRS groups. RESULTS: One hundred and three patients were classified as having ARS and fifty-one had CRS. Their mean (+/- SD) age was 5.9 +/- 3.3 years. Allergic rhinitis was common in the chronic rhinosinusitis group. The most common main complaints in acute and chronic rhinosinusitis were cough and rhinorrhea. There was no significant difference in symptoms between both groups, except for periorbital pain and sleep apnea which were found more frequently in the chronic group. Sixty five percents of ARS and 58.8% of CRS had abnormal x-ray findings. Adenoid hypertrophy was found in the CRS group. There was overall improvement after 14.6 +/- 3.82 days and 22.35 +/- 5.04 days (mean) of antibiotic treatment in the ARS and CRS groups, respectively. None of the patient underwent sinus surgery. CONCLUSION: The most common RS symptoms were rhinorrhea and cough. Patients with allergic rhinitis had a higher risk of developing chronic rhinosinusitis. Patients with ARS and CRS were successfully treated with medical treatment.