Potential for intraoperative assessment of excised lung samples by X-ray histology

More than 24,000 operations to remove all or part of a patient’s lung take place in Europe each year. The full extent and the type of changes in lung tissue microstructure due to disease may not be evident until surgery is underway, therefore, immediate and informative microanatomical assessment of excised tissue can guide the surgical team or assist with diagnosis. We explored the feasibility of using micro-Computed Tomography (µCT) based X-ray histology (XRH) for timely 3D histological imaging during surgery. Key criteria considered include: (1) visualisation of relevant microanatomical structures (2) results within the 20-minute intraoperative ‘window’ (3) rapid and comprehensive presentation of data-rich 3D images and (4) compatibility with current intraoperative and post-operative pathology workflows. For protocol development, porcine lung was used due to its structural similarities to human lung. Using optimised µCT scan conditions at our XRH facility in Southampton, consistent 3D imaging of fresh, unfixed, peripheral lung samples was demonstrated (n=6), providing relevant microanatomical information in less than 10 minutes (Fig. 1). Short scan times (under 4 minutes) minimised sample movement artefacts in the images. Snap-freezing and/or air-inflation of lung samples were also feasible within the intraoperative window. However, both required additional sample preparation steps and introduced artefacts (e.g. cracks, movement, cryo-damage of tissue). Complementing our rapid XRH imaging protocol, a system for fast, automated generation of user-friendly reports was also developed. This brings together sample images and details for assessment, patient records and clinical team discussions. To streamline the integration of XRH with existing protocols we scanned samples in standard containers used to transfer surgical samples to the pathology lab. This allows fast, non-invasive, non-contact scanning in a sealed container, thus reducing sample handling and avoiding contamination. Pathologists judged the XRH data generated to be of potential diagnostic quality. This approach provides opportunities for both research and diagnostic use. To find out more and see if 3D X-ray histology can benefit you, please visit www.xrayhistology.org.