New method in the age estimation by the spheno-occipital suture. 3D cone-beam CT application

The aim of the present study was to determine the sequence and timing of closure of the spheno-occipital synchondrosis for a large sample of a modern Italian population to assess if this age marker is a useful tool for age estimation for individuals. The sample consisted of 494 individuals in the age range 0-22 years, who were admitted to the Department of Radiology, Oncology and Anatomo-Pathology of "Sapienza" University of Rome - UOC Head and Neck Radiology - and the Department of imaging, University of L'Aquila, and who had undergone multi-slice CBCT imaging. The average age of the spheno-occipital closure in men is 18.3 years, whilst in women is 16.6. Therefore, it is evident that the closure in female people is faster than 1.7 years. The timing of closure of spheno-occipital suture can be used to understand the age, even if the research has to be implemented

Thoracic and lumbar vertebral bone mineral density changes in a natural occuring dog model of diffuse idiopathic skeletal hyperostosis

Ankylosing spinal disorders can be associated with alterations in vertebral bone mineral density (BMD). There is however controversy about vertebral BMD in patients wuse idiopathic skeletal hyperostosis (DISH). DISH in Boxer dogs has been considered a natural occurring disease model for DISH in people. The purpose of this study was to compare vertebral BMD between Boxers with and without DISH. Fifty-nine Boxers with (n=30) or without (n=29) DISH that underwent computed tomography were included. Vertebral BMD was calculated for each thoracic and lumbar vertebra by using an earlier reported and validated protocol. For each vertebral body, a region of interest was drawn on the axial computed tomographic images at three separate locations: immediately inferior to the superior end plate, in the middle of the vertebral body, and superior to the inferior end plate. Values from the three axial slices were averaged to give a mean Hounsfield Unit value for each vertebral body. Univariate statistical analysis was performed to identify factors to be included in a multivariate model. The multivariate model including all dogs demonstrated that vertebral DISH status (Coefficient 24.63; 95% CI 16.07 to 33.19; p < 0.001), lumbar vertebrae (Coefficient -17.25; 95% CI -23.42 to -11.09; p < 0.01), and to a lesser extent higher age (Coefficient -0.56; 95% CI -1.07 to -0.05; p = 0.03) were significant predictors for vertebral BMD. When the multivariate model was repeated using only dogs with DISH, vertebral DISH status (Coefficient 20.67; 95% CI, 10.98 to 30.37; p < 0.001) and lumbar anatomical region (Coefficient -38.24; 95% CI, -47.75 to -28.73; p < 0.001) were again predictors for vertebral BMD but age was not. The results of this study indicate that DISH can be associated with decreased vertebral BMD. Further studies are necessary to evaluate the clinical importance and pathophysiology of this finding

Thoracic and Lumbar Vertebral Bone Mineral Density Changes in a Natural Occurring Dog Model of Diffuse Idiopathic Skeletal Hyperostosis

Ankylosing spinal disorders can be associated with alterations in vertebral bone mineral density (BMD). There is however controversy about vertebral BMD in patients wuse idiopathic skeletal hyperostosis (DISH). DISH in Boxer dogs has been considered a natural occurring disease model for DISH in people. The purpose of this study was to compare vertebral BMD between Boxers with and without DISH. Fifty-nine Boxers with (n=30) or without (n=29) DISH that underwent computed tomography were included. Vertebral BMD was calculated for each thoracic and lumbar vertebra by using an earlier reported and validated protocol. For each vertebral body, a region of interest was drawn on the axial computed tomographic images at three separate locations: immediately inferior to the superior end plate, in the middle of the vertebral body, and superior to the inferior end plate. Values from the three axial slices were averaged to give a mean Hounsfield Unit value for each vertebral body. Univariate statistical analysis was performed to identify factors to be included in a multivariate model. The multivariate model including all dogs demonstrated that vertebral DISH status (Coefficient 24.63; 95% CI 16.07 to 33.19; p <0.001), lumbar vertebrae (Coefficient -17.25; 95% CI -23.42 to -11.09; p < 0.01), and to a lesser extent higher age (Coefficient -0.56; 95% CI -1.07 to -0.05; p = 0.03) were significant predictors for vertebral BMD. When the multivariate model was repeated using only dogs with DISH, vertebral DISH status (Coefficient 20.67; 95% CI, 10.98 to 30.37; p < 0.001) and lumbar anatomical region (Coefficient -38.24; 95% CI, -47.75 to -28.73; p < 0.001) were again predictors for vertebral BMD but age was not. The results of this study indicate that DISH can be associated with decreased vertebral BMD. Further studies are necessary to evaluate the clinical importance and pathophysiology of this finding

The Applications of Cone-Beam Computed Tomography in Endodontics: A Review of Literature

By producing undistorted three-dimensional images of the area under examination, cone-beam computed tomography (CBCT) systems have met many of the limitations of conventional radiography. These systems produce images with small field of view at low radiation doses with adequate spatial resolution that are suitable for many applications in endodontics from diagnosis to treatment and follow-up. This review article comprehensively assembles all the data from literature regarding the potential applications of CBCT in endodontics

Perception of Bone Mineral Loss on Cone-Beam Computed Tomography (CBCT) & Digital Periapical (PA) Film: An Ex-Vivo Comparison

Using micro computed tomography (micro-CT) as a reference standard, the purpose of this investigation was to evaluate the influences of bone mineral loss and radiographic contrast in digital periapical (PA) film and cone-beam computed tomography (CBCT). Seven dog and human mandibles were sectioned, followed by modification via cortical bone drilling to create 248 lesions and/or trabecular bone acid demineralization to create 96 coronal slice pairs. Pretreatment and post-treatment radiographs (PA, CBCT, and/or micro-CT) were taken for lesion rating/perception in addition to two-dimensional (area) and three-dimensional (volumetric) measurements of 50 drilling lesions and 20 coronal slice pairs. 4-7% bone mineral loss is needed for radiographic perception of cortical bone drilling lesions (rating ≥3), and at least 17.34% bone mineral loss is needed for trabecular bone acid demineralization perception. Radiographic contrast indices were difficult to ascertain and may be related to regional differences and lesion anatomical location. This study suggests that even though %BML is a major factor in radiographic lesion perception, additional factors of regional and anatomical contrast influence lesion rating. With a limited sample size, further testing is needed to investigate cortical bone lesion perception differences between dog and human mandibles, to quantify radiographic contrast, and to identify more precise trabecular bone demineralization thresholds

Multimodal image fusion of anatomical structures for diagnosis, therapy planning and assistance

This paper provides an overview of work done in recent years by our research group to fuse multimodal images of the trunk of patients with Adolescent Idiopathic Scoliosis (AIS) treated at Sainte-Justine University Hospital Center (CHU). We first describe our surface acquisition system and introduce a set of clinical measurements (indices) based on the trunk's external shape, to quantify its degree of asymmetry. We then describe our 3D reconstruction system of the spine and rib cage from biplanar radiographs and present our methodology for multimodal fusion of MRI, X-ray and external surface images of the trunk We finally present a physical model of the human trunk including bone and soft tissue for the simulation of the surgical outcome on the external trunk shape in AIS.CIHR / IRS

Advanced Image Reconstruction for Limited View Cone-Beam CT

In a standard CT acquisition, a high number of projections is obtained around the sample, generally covering an angular span of 360º. However, complexities may arise in some clinical scenarios such as surgery and emergency rooms or Intensive Care Units (ICUs) when the accessibility to the patient is limited due to the monitoring equipment attached. X-ray systems used in these cases are usually C-arms that only enable the acquisition of planar images within a limited angular range. Obtaining 3D images in these scenarios could be extremely interesting for diagnosis or image guided surgery. This would be based on the acquisition of a small number of projections within a limited angular span. Reconstruction of these limited-view data with conventional algorithms such as FDK result in streak artifacts and shape distortion deteriorating the image quality. In order to reduce these artifacts, advanced reconstruction methods can be used to compensate the lack of data by the incorporation of prior information. This bachelor thesis is framed on one of the lines of research carried out by the Biomedical Imaging and Instrumentation group from the Bioengineering and Aerospace Department of Universidad Carlos III de Madrid working jointly with the Hospital General Universitario Gregorio Marañón through its Instituto de Investigación Sanitaria. This line of research is carried out in collaboration with the company SEDECAL, which enables the direct transfer to the industry. Previous work showed that a new iterative reconstruction method proposed by the group, SCoLD, is able to restore the altered contour of the object, suppress greatly the streak artifacts and recover to some extend the image quality by restricting the space of search with a surface constraint. However, the evaluation was only carried out using a simulated mask that described the shape of the object obtained by thresholding a previous CT image of the sample, which is generally not available in real scenarios. The general objective of this thesis is the designing of a complete workflow to implement SCoLD in real scenarios. For that purpose, the 3D scanner Artec Eva was chosen to acquire the surface information of the sample, which was then transformed to be usable as prior information for SCoLD method. The evaluation done in a rodent study showed high similarity between the mask obtained from real data and the ideal mask obtained from a CT. Distortions in shape and streak artifacts in the limited-view FDK reconstruction were greatly reduced when using the real mask with the SCoLD reconstruction and the image quality was highly improved demonstrating the feasibility of the proposal.Grado en Ingeniería Biomédica (Plan 2010

Review of the radiographic modalities used during dental implant therapy - A narrative

The introduction of digital x-ray receivers which replaced conventional films was a significant radiographic development that is commonly used in daily dental practice. Dental implant therapy (DIT) is a sought after dental therapeutic intervention and dental radiography is an essential component contributing to the success of treatment. Dental radiographs taken in daily practice are generally conventional two-dimensional images and/or three-dimensional images. Ideally, the choice of radiographic technique should be determined after a thorough clinical examination and comprehensive consideration of the advantages, indications, and drawbacks. Digital three-dimensional modalities that have emerged over the last decade have been incorporated into DIT with the assumption that treatment outcomes will be improved. These modalities are constantly being reassessed and improved but there is a paucity of published information regarding the assessment of variables such as dosages and dimensional accuracy, suggesting that further research in these matters is necessary. This is crucial in order to obtain evidence-based information that may influence future radiographic practices. In this narrative, the authors present the most commonly used dental radiographic modalities currently used in DIT