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Background: Diagnosis of COVID-19 can be challenging in trauma patients, especially those with chest trauma and lung contusion. Methods: We present a case series of patients from February and March 2020 who were admitted to our trauma center at Rajaee Hospital Trauma Center, in Shiraz, Iran and had positive SARS-CoV-2 PCR test or chest CT scan suggestive of COVID-19 and were admitted to the specific ICU for COVID-19. Results: Eight COVID-19 patients (6 male) with mean age of 40 (SD = 16.3) years old, were presented. All patients were cases of trauma injuries, with multiple injuries including chest trauma and lung contusion, admitted to our trauma center for management of their injuries, but they were diagnosed with COVID-19 as well. Two of them had coinfection of influenza type-B and SARS-CoV-2. All patients were treated for COVID-19 and three of them died; the rest were discharged from hospital. Conclusion: Since PCR for SARS-CoV-2 is not always sensitive enough to confirm the cause of pneumonia, chest CT manifestations can be helpful, though, they are not always differentiable from lung contusion. Therefore, both the CT scan and the clinical and paraclinical presentation and course of improvement can be beneficial in diagnosing COVID-19 in the trauma setting. [ABSTRACT FROM AUTHOR]

Introduction: Photoelectric effect and X-ray scattering determine the attenuation coefficient of materials in diagnostic radiology. This manuscript presents an iterative gradient search method to separate the contributions to attenuation from these two independent sources. This issue assumes importance due to two reasons, including 1) Electron density determination of scanned materials and 2) correct dose calculation in diagnostic radiology. Material and Methods: A special water-filled phantom which was custom-built for simultaneous scanning of 12 samples was used in the current study. Attenuation coefficient equations were iteratively solved to calculate the contributions from x-ray scattering and photoelectric effects. Results: Data converged after five iterations (within 1%). Error in the attenuation coefficient was measured at ±3%. Conclusion: As evidenced by the obtained results, this method can be used to determine the Compton and photoelectric contributions with sufficient accuracy. Moreover, the inversion of Dual-Energy computed tomography (DECT) data for finding electron density and effective atomic number of materials also presents satisfactory results. [ABSTRACT FROM AUTHOR]

Purpose: Restricting the gradients of dwell times between adjacent dwell positions can potentially be beneficial in reducing the probability of unwanted hot/cold spots occurring, if the planned applicators/anatomy relative positions change before or during treatment. This constraint, however, may degrade plan quality. This study, for the first time, aims to quantify the impact of modulation restriction on plan quality indices in inverse optimization for cervix highdose- rate (HDR) brachytherapy using the BEBIG SagiPlan treatment planning system. Material and methods: Ten cervical cancer patient plans were optimized for treatment with a BEBIG SagiNova 60Co HDR afterloader using the min/max inverse planning method, with dwell time homogeneity error weight (DTHEW) parameter values of 0 to 10. Dwell time homogeneity and gradients as well as various plan quality indices were analyzed. Results: For DTHEW = 0, min/max-based optimization yielded higher HR-CTV D90 values than the variance-based option (p < 0.001) and was therefore selected for this study. Averaging over all patients, selecting non-zero DTHEWs resulted in a general increase in dwell time homogeneity and decrease in mean and maximum adjacent dwell time gradients, especially between DTHEWs of 0 and 1. For DTHEW > 1, an increase of this parameter did not always result in more homogeneous dwell times or reduced gradients in individual patients. There was a negative correlation between DTHEW and both HR-CTV D90 and V100 (p < 0.001, r = –0.91). Increasing DTHEW also negatively affected conformity index (p < 0.001, r = –0.99). Changes in rectum and sigmoid colon D2cc were insignificant. There was a strong positive relationship between bladder D2cc and DTHEW (p < 0.001, r = 0.99). Conclusions: Assuming a static geometry, statistically significant degradation of plan quality can result from restricting the dwell time homogeneity in min/max-based optimization of cervix HDR brachytherapy plans using SagiPlan. Therefore, setting DTHEW to zero is indicated for the type of patient plans considered in this study. [ABSTRACT FROM AUTHOR]

Statement of the Problem: Impaction of foreign bodies in the soft tissues is a sequela of traumatic and penetrating injuries. Such foreign bodies should be removed due to the complications they cause. Patient's history, clinical evaluation and imaging examinations aid in the proper detection and localization of the foreign bodies. Purpose: The aim of the present study was to compare the sensitivity of computed tomography (CT) and ultrasonography for detecting foreign bodies in in-vitro models simulating facial soft tissues. Materials and Method: Fifty foreign particles with five different compositions including wood, glass, metal, plastic, and stone were embedded in five calf tongues at 1, 2, 3, 4 and 5 cm depths. CT and ultrasonography were compared regarding their capability of detecting and localizing the foreign bodies. Results: Wood and plastic foreign bodies were demonstrated more clearly on ultrasonography images. High density materials such as metal, stone, and glass were detected with almost the same accuracy on CT and ultrasonography examinations. Visibility of the foreign bodies deteriorated on ultrasonography images as their depth increased; however, CT appearances of the foreign particles were not influenced by their depths. Conclusion: Ultrasonography is an appropriate technique for detection of foreign bodies especially the ones with low density. Therefore, it seems logical to perform ultrasonography in combination with CT in cases with the suspicion of foreign body impaction. [ABSTRACT FROM AUTHOR]