Non-invasive identification and characterisation of wooden cultural heritage through Hounsfield unit-based CT imaging

X-ray Computed Tomography (CT) is a well-established non-destructive imaging technique widely employed to examine the internal structures and materials of complex objects, offering crucial insights for conservation and restoration efforts. However, its application for direct material identification in cultural heritage contexts is partially explored. In this work, the CT imaging approach based on the Hounsfield Units (HU) scale—traditionally used in medical radiology and directly correlated with the linear attenuation coefficient (µ) and material density (kg/m³) were employed to analyze the wooden support of a seventeenth-century panel painting from the National Academy of San Luca Gallery in Rome and the wooden support of an Egyptian coffin from the collection of the Vatican Museums. HU values obtained from the case studies were quantitatively compared with those from reference wood samples scanned under identical conditions, enabling reasonably accurate material characterization. The obtained HU values allowed for a confident, non-invasive identification of wood species present in the samples highlighting the diagnostic value of HU mapping in heritage applications.