HBIM to Virtual Reality Workflow for Industrial Archaeology Immovable Assets’ Management: A Case Study

As a witness on the industrialization in Bologna, since its first generation was born in the late 1760, the Battiferro lock has been coping with the innovation that the city experienced throughout the centuries, until it has lost its functionality due to the technological development for which Bologna’s canals were gradually covered starting from the 1950s under Giuseppe Dozza ’s administration, as part of the reconstruction, reclamation and urban requalification that was carried out in the aftermath the World War II and which involved the whole city. The interest of the research carried out on this case study was primarily to reintroduce the landmark that is still intact, to what is considered to be the fourth generation of the industrial revolution, namely in the construction field, which is recognized as Construction 4.0, by means of the Historic (or Heritage) Information Modeling HBIM and Virtual Reality (VR) application. A scan-to-BIM approach was followed to create 3D as-built BIM model, as a first step towards the storytelling of the abandoned industrial built asset in VR environment, or as a seed for future applications such as Digital Twins (DT), heritage digital learning, sustainable impact studies, and/or interface with other interfaces such as GIS. Based on the HBIM product, examples of the primary BIM deliverables such as 2D layouts is given, then a workflow to VR is proposed and investigated the reliability of data and the type of users that may benefit of the VR experience, then the potential future development of the model is investigated, with comparison of a relatively similar experience in the UK.

Experimental evaluation of the z-resolution in different clinical Digital Breast Tomosynthesis systems using commercial phantoms

Digital Breast Tomosynthesis (DBT) is an advanced mammography technique based on the reconstruction of a pseudo-volumetric image. To date, image quality represents the most deficient section of DBT quality control protocols. In fact, related tests are not yet characterized by either action levels or typical values. This thesis work focuses on the evaluation of one aspect of image quality: the z-resolution. The latter is studied in terms of Artifact Spread Function (ASF), a function that describes the signal spread of a detail along the reconstructed focal planes. To quantify the ASF numerically, its Full Width at Half Maximum (FWHM) is calculated and used as a representative index of z-resolution. Experimental measurements were acquired in 24 DBT systems, of 7 different models, currently in use in 20 hospital facilities in Italy. The analysis, performed on the clinical reconstructed images, of 5 different commercial phantoms, lead to the identification of characteristic FWHM values for each type of DBT system. The ASF clearly showed a dependence on the size of the detail, providing higher FWHM values for larger objects. The z-resolution was found to be positively influenced by the acquisition angle: Fujifilm sistematically showed wider ASF profiles in ST mode (15°) than in HR mode (40°). However, no clear relationship was found between angular range and ASF, among different DBT systems, due to the influence of the peculiarities of each reconstruction algorithm. The experimental approach shown in this thesis work can be proposed as a z-resolution quality control test procedure. Contextually, the values found could be used as a starting point for identifying typical values to be included in the test, in a DBT protocol. Clearly, a statistically significant number of images is needed to do this. The equipment involved in this work is located in hospitals and is not available for research purposes, so only a limited amount of data was acquired and processed.