We quantify the variation in resolution due to anisotropy caused by oblique X-ray incidence in indirect flat-panel detectors for computed tomography breast imaging systems. We consider a geometry and detector type utilized in breast computed tomography (CT) systems currently being developed. Our methods rely on mantis, a combined X-ray, electron, and optical Monte Carlo transport open source code. The physics models are the most accurate available in general-purpose Monte Carlo packages in the diagnostic energy range. We consider maximum-obliquity angles of 10 ( degrees ) and 13 ( degrees ) at the centers of the 30 and 40 cm detector edges, respectively, and 16 ( degrees ) at the corner of the detector. Our results indicate that blur is asymmetric and that the resolution properties vary significantly with the angle (or location) of incidence. Our results suggest that the asymmetry can be as high as a factor of 2.6 between orthogonal directions. Anisotropy maps predicted by mantis provide an understanding of the effect that such variations have on the imaging system and allow more accurate modeling and optimization of breast CT systems. These maps of anisotropy across the detector could lead to improved reconstruction and help motivate physics-based strategies for computer detection of breast lesions.
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http://dx.doi.org/10.1109/TMI.2008.2010443 | DOI Listing |
Eur J Trauma Emerg Surg
January 2025
Department of Trauma and Orthopedic Surgery, University Hospital Erlangen, Friedrich-Alexander University Erlangen-Nürnberg (FAU), Erlangen, Germany.
Background: Rib and sternum fractures are common injuries associated with cardiopulmonary resuscitation (CPR). The fracture mechanism is either direct by application of force on sternum and anterior ribs or indirect by bending through compression of the thorax. The aim of this study was to determine morphologies of rib fractures after CPR and to reevaluate prior findings on fracture localisation, type and degree of dislocation.
View Article and Find Full Text PDFJ Periodontal Res
January 2025
Department of Radiology, University of Michigan, Ann Arbor, Michigan, USA.
Aim: Ultrasonography (US) has shown accuracy in imaging healthy periodontium. This study aims to evaluate the feasibility and accuracy of US for estimating dimensions of inflamed periodontium induced by ligature and bacteria.
Methods: Periodontal tissues of maxillary as well as mandibular premolars and molars in six female mini pigs were treated with ligature and three strains of bacteria for 4-10 weeks.
BMC Oral Health
January 2025
Department of Conservative Dentistry, College of Dentistry, Kyung Hee University, 26-6, Kyungheedae-ro, Dongdaemun-gu, Seoul, 02453, Republic of Korea.
Background: This study aims to compare design, phase transformation behavior, and torsional resistance of the ProGlider (PG) and ProTaper ultimate slider (PUS) and to compare the performance of two files in the glide-path preparation of a double-curved artificial canal.
Methods: Scanning electron microscopy, micro-computed tomography, and differential scanning calorimetry were used to characterize the samples. A torsional resistance test was performed to obtain ultimate strength and distortion angle.
Int J Oral Maxillofac Surg
January 2025
Stomatological Hospital of Chongqing Medical University, Chongqing, China; Chongqing Municipal Key Laboratory of Oral Biomedical Engineering of Higher Education, Chongqing, China; Chongqing Key Laboratory of Oral Diseases and Biomedical Sciences, Chongqing, China. Electronic address:
The retrospective study aimed to compare the space-maintaining effects of sticky bone (bone graft matrix enriched with injectable platelet-rich fibrin) and titanium mesh for bone augmentation in the aesthetic zone. Patients who underwent single implant placement and had type 2/4 alveolar bone defects (buccal bone wall loss is >50% of the expected implant length) were screened for inclusion in this study. The labial bone plate width was measured at 1, 3, and 5 mm below the apical implant platform on cone beam computed tomography images taken immediately and 6 months after surgery.
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