Fractal dimension analysis of malignant and benign endobronchial ultrasound nodes

Background: Endobronchial ultrasonography (EBUS) has been applied as a routine procedure for the diagnostic of hiliar and mediastinal nodes. The authors assessed the relationship between the echographic appearance of mediastinal nodes, based on endobronchial ultrasound images, and the likelihood of malignancy.; Methods: The images of twelve malignant and eleven benign nodes were evaluated. A previous processing method was applied to improve the quality of the images and to enhance the details. Texture and morphology parameters analyzed were: the image texture of the echographies and a fractal dimension that expressed the relationship between area and perimeter of the structures that appear in the image, and characterizes the convoluted inner structure of the hiliar and mediastinal nodes.; Results: Processed images showed that relationship between log perimeter and log area of hilar nodes was lineal (i.e. perimeter vs. area follow a power law). Fractal dimension was lower in the malignant nodes compared with non-malignant nodes (1.47(0.09), 1.53(0.10) mean(SD), Mann-Whitney U test p < 0.05)).; Conclusion: Fractal dimension of ultrasonographic images of mediastinal nodes obtained through endobronchial ultrasound differ in malignant nodes from non-malignant. This parameter could differentiate malignat and non-malignat mediastinic and hiliar nodes.Peer ReviewedPostprint (published version

Experimental analysis of nanostructured PEEK, African giant snail shell, and sea snail shell powder for hydroxyapatite formation for bone implant applications

This experimental research focuses on the nanostructure analysis of three materials; polyether ether ketone (PEEK), African land giant snail shell (ALGSS), and sea snail shell (SSS) powder, for the formation of hydroxyapatite (HA) coatings in bone implant applications. The study aimed to evaluate these materials’ surface characteristics, furrow depth, density, and other relevant parameters to assess their suitability as bone implant materials. The nanostructure analysis revealed distinct characteristics for each material. PEEK exhibited shallow furrows and a high density of furrows, making it a favourable substrate for hydroxyapatite coating formation. The ISO 25178 roughness analysis further characterised surface roughness and topography. African land giant snail shell powder, displayed a high material ratio, indicating a potential for hydroxyapatite conversion for biomedical application. The sea snail shell powder demonstrated intermediate furrow depth and density, warranting further investigation for optimisation as a precursor for hydroxyapatite coatings. The findings emphasise the significance of nanostructure properties in bone implant materials. The tailored nanostructure of materials such as PEEK, the synthesized powder can influence their biocompatibility, osseointegration, and long-term performance. The novelty of this research lies in the comprehensive analysis of the nanostructure properties of these materials, contributing to the understanding of their potential for bone implant applications. Overall, this experimental research is significant and provides valuable insights into the nanostructure characteristics of PEEK, African land giant snail shell powder, and sea snail shell powder and they all demonstrated the potential of forming hydroxyapatite coatings.</p

ULTRA CLOSE-RANGE DIGITAL PHOTOGRAMMETRY AS A TOOL TO PRESERVE, STUDY, AND SHARE SKELETAL REMAINS

Skeletal collections around the world hold valuable and intriguing knowledge about humanity. Their potential value could be fully exploited by overcoming current limitations in documenting and sharing them. Virtual anthropology provides effective ways to study and value skeletal collections using three-dimensional (3D) data, e.g. allowing powerful comparative and evolutionary studies, along with specimen preservation and dissemination. CT- and laser scanning are the most used techniques for three-dimensional reconstruction. However, they are resource-intensive and, therefore, difficult to be applied to large samples or skeletal collections. Ultra close-range digital photogrammetry (UCR-DP) enables photorealistic 3D reconstructions from simple photographs of the specimen. However, it is the least used method in skeletal anthropology and the lack of appropriate protocols often limit the quality of its outcomes. This Ph.D. thesis explored UCR-DP application in skeletal anthropology. The state-of-the-art of this technique was studied, and a new approach based on cloud computing was proposed and validated against current gold standards. This approach relies on the processing capabilities of remote servers and a free-for-academic use software environment; it proved to produce measurements equivalent to those of osteometry and, in many cases, they were more precise than those of CT-scanning. Cloud-based UCR-DP allowed the processing of multiple 3D models at once, leading to a low-cost, quick, and effective 3D production. The technique was successfully used to digitally preserve an initial sample of 534 crania from the skeletal collections of the Museo Sardo di Antropologia ed Etnografia (MuSAE, Università degli Studi di Cagliari). Best practices in using the technique for skeletal collection dissemination were studied and several applications were developed including MuSAE online virtual tours, virtual physical anthropology labs and distance learning, durable online dissemination, and values-led participatorily designed interactive and immersive exhibitions at the MuSAE. The sample will be used in a future population study of Sardinian skeletal characteristics from the Neolithic to modern times. In conclusion, cloud-based UCR-DP offers many significant advantages over other 3D scanning techniques: greater versatility in terms of application range and technical implementation, scalability, photorealistic restitution, reduced requirements relating to hardware, labour, time, and cost, and is, therefore, the best choice to document and value effectively large skeletal samples and collections

A volume filtering and rendering system for an improved visual balance of feature preservation and noise suppression in medical imaging

Preserving or enhancing salient features whilst effectively suppressing noise-derived artifacts and extraneous detail have been two consistent yet competing objectives in volumetric medical image processing. Illustrative techniques (and methods inspired by them) can help to enhance and, if desired, isolate the depiction of specific regions of interest whilst retaining overall context. However, highlighting or enhancing specific features can have the undesirable side-effect of highlighting noise. Second-derivative based methods can be employed effectively in both the rendering and volume filtering stages of a visualisation pipeline to enhance the depiction of feature detail whilst minimising noise-based artifacts. We develop a new 3D anisotropic-diffusion PDE for an improved balance of feature-retention and noise reduction; furthermore, we present a feature-enhancing visualisation pipeline that can be applied to multiple modalities and has been shown to be particularly effective in the context of 3D ultrasound

Study on quality in 3D digitisation of tangible cultural heritage: mapping parameters, formats, standards, benchmarks, methodologies and guidelines: final study report.

This study was commissioned by the Commission to help advance 3D digitisation across Europe and thereby to support the objectives of the Recommendation on a common European data space for cultural heritage (C(2021) 7953 final), adopted on 10 November 2021. The Recommendation encourages Member States to set up digital strategies for cultural heritage, which sets clear digitisation and digital preservation goals aiming at higher quality through the use of advanced technologies, notably 3D. The aim of the study is to map the parameters, formats, standards, benchmarks, methodologies and guidelines relating to 3D digitisation of tangible cultural heritage. The overall objective is to further the quality of 3D digitisation projects by enabling cultural heritage professionals, institutions, content-developers, stakeholders and academics to define and produce high-quality digitisation standards for tangible cultural heritage. This unique study identifies key parameters of the digitisation process, estimates the relative complexity and how it is linked to technology, its impact on quality and its various factors. It also identifies standards and formats used for 3D digitisation, including data types, data formats and metadata schemas for 3D structures. Finally, the study forecasts the potential impacts of future technological advances on 3D digitisation

Implementation of Video Compression Standards in Digital Television

In this paper, a video compression standard used in digital television systems is discussed. Basic concepts of video compression and principles of lossy and lossless compression are given. Techniques of video compression (intraframe and interframe compression), the type of frames and principles of the bit rate compression are discussed. Characteristics of standard-definition television (SDTV), high-definition television (HDTV) and ultra-high-definition television (UHDTV) are given. The principles of the MPEG-2, MPEG-4 and High Efficiency Video Coding (HEVC) compression standards are analyzed. Overview of basic standards of video compression and the impact of compression on the quality of TV images and the number of TV channels in the multiplexes of terrestrial and satellite digital TV transmission are shown. This work is divided into six sections