Search results for "TOMS"
showing 10 items of 1058 documents
Automated detection of patient movement during a CBCT scan based on the projection data.
2015
Objectives To develop an automated procedure to detect patient motion on the projection images acquired during a cone beam computed tomography (CBCT) scan and to evaluate the method's feasibility on small real-world CBCT images in relation to visual assessment. Methods Based on optical flow theory, software was developed using the sequence of the projection images of a CBCT machine for automated detection of patient motion. Averaged acceleration vectors were used as measurement data and compared with visual assessment of the projection images displayed as video. Seventy-nine CBCT data sets (small field-of-view: 40 mm) from our patient database were selected in a sequential fashion and evalu…
Evaluation of lens absorbed dose with Cone Beam IGRT procedures
2015
The purpose of this work is to evaluate the absorbed dose to the eye lenses due to the cone beam computed tomography (CBCT) system used to accurately position the patient during head-and-neck image guided procedures. The on-board imaging (OBI) systems (v.1.5) of Clinac iX and TrueBeam (Varian) accelerators were used to evaluate the imparted dose to the eye lenses and some additional points of the head. All CBCT scans were acquired with the Standard-Dose Head protocol from Varian. Doses were measured using thermoluminescence dosimeters (TLDs) placed in an anthropomorphic phantom. TLDs were calibrated at the beam quality used to reduce their energy dependence. Average dose to the lens due to …
Alignment of cone beam computed tomography data using intra-oral fiducial markers.
2009
This article illustrates a new method to align and merge two partially overlapping volumes each of them generated by cone beam computed tomography (CBCT). The aggregate volume covers a larger area of investigation and is determined by localizing one fixed LEGO brick in both of the primal volumes. Based on the LEGO brick an approximate registration of the volumes is determined. Afterwards we improve the transformation by minimizing the difference in overlapping space. In this paper we present a method which automates these two steps and provides an aligned volume.
Interobserver and intraobserver variability in the radiological assessment of sialolithiasis using cone beam computed tomography
2021
Background Data regarding the inter- and intraobserver variability in the radiological assessment of sialolithiasis using cone beam computed tomography are missing in the current literature. This study assessed the inter- and intraobserver variability in the radiological assessment of sialolithiasis using cone beam computed tomography (CBCT). Material and Methods In 107 patients, 130 salivary glands (65 parotid and 65 submandibular) with clinical signs of obstruction were assessed by four independent observers; 2 residents OMFS and 2 experienced OMFS. The observers analyzed the CBCT images and determined the absence or presence of one or more salivary stones in the affected gland. This proc…
Contrast perception in digitized panoramic radiographs compared with their film-based origin
2002
Abstract Objectives. We sought to compare the visual image quality of film-based and digitized panoramic radiographs through use of a hole-containing test wedge. Study Design. An aluminum wedge containing 100 cells, of which 90 were given shallow holes, was exposed in the film-based Orthophos CD panoramic unit. Two radiographs subjectively exhibiting optimum contrast were selected. Films were digitized with a charge-coupled device flatbed scanner at 300 dpi. Films and digitized images were rated cellwise by 2 similar groups of 50 observers each with respect to spot perception. Results. The mean sensitivity was 0.26 ± 0.09 for film and 0.20 ± 0.07 for digitized images (P =.000), with a prono…
Molecular, Supramolecular Structures Combined with Hirshfeld and DFT Studies of Centrosymmetric M(II)-azido {M=Ni(II), Fe(II) or Zn(II)} Complexes of…
2021
The supramolecular structures of the three metal (II) azido complexes [Fe(4bzpy)4(N3)2]
2018
Social identification has been shown to be a protective resource for mental health. In this study, the relationships between social identification and emotional, as well as cognitive symptoms of test anxiety are investigated. Participants were university students diagnosed with test anxiety ( N = 108). They completed questionnaires regarding a range of psychopathologic stress symptoms, and their social identification with fellow students and with their study program. Results reveal negative relations between social identification and almost all investigated emotional and cognitive symptoms of test anxiety. Based on this study, interventions could be developed that strengthen the social ide…
Study Protocol—Coping With the Pandemics: What Works Best to Reduce Anxiety and Depressive Symptoms
2021
Background: The coronavirus disease 2019 (COVID-19) pandemic and lockdown might increase anxiety and depressive symptoms in most individuals. Health bodies recommend several coping behaviors to protect against such symptoms, but evidence on the relationship between these behaviors and symptoms mostly comes from cross-sectional studies in convenience samples. We will conduct a prospective longitudinal study of the associations between coping behaviors and subsequent anxiety and depressive symptoms during the COVID-19 pandemic in a representative sample of the Spanish general adult population.Methods: We will recruit 1,000 adult participants from all autonomous communities of Spain and with s…
Internet-Based Intervention for Secondary and Tertiary Prevention of Depressive Symptoms
2016
Depression is one of the most disabling psychological disorders worldwide. A very important challenge today consists on addressing the issue of depression from a preventive perspective. A growing body of research supports the efficacy of Internet-based treatments. We have developed an Internet-based program (Smiling is Fun) with the objective of helping people in prevention of depression and anxiety symptoms. It is based on classical cognitive behavioral techniques, such as behavioural activation, and also includes other positive psychological strategies to improve coping ability and positive mood. We applied this intervention program in people who had to cope at least with one stressor in …
Teacher coping profiles in relation to teacher well-being : a mixed method approach
2021
The aim was to investigate teachers’ coping profiles and their relations to teacher well-being. Questionnaire data was collected from 107 Finnish teachers. Theory-driven content analysis of teachers’ responses revealed three coping categories: problem-focused, emotion-focused and mixed problem- and emotion-focused. Next, teachers were categorized into four coping profiles by using latent profile analysis: Low-coping users (21%), Problem-focused-coping users (15%), High-coping users (12%) and Emotion-focused-coping users (52%). Low-coping-user teachers reported less stress and fewer depressive symptoms and sleep problems compared to Emotion-focused-coping users. Using a compact amount of cop…