Evaluating the feasibility of region-of-interest X-ray phase contrast imaging for lung cancer diagnostics.

Lung cancer is one of the world's deadliest cancers, often not diagnosed until it has spread beyond the lung, in part due to limitations in current medical imaging. Insufficient detail in diagnostic images can mean that patients require a biopsy to gain a full understanding of their prognosis. Here, we investigate the use of propagation-based X-ray phase-contrast imaging to capture high-resolution region-of-interest 3D Computed-Tomography (CT) images of suspicious masses, using a human chest phantom. In this study, we imaged a 3.5 cm region within the chest phantom, with each CT slice amounting to approximately 1% of the area of the whole chest at that height. X-ray energies ranging from 50 to 80 keV and propagation distances of 0 to 7 m were tested. We were able to quantify the experimental parameters that would be required to increase soft-tissue sensitivity and spatial resolution relative to conventional X-ray imaging methods, and hence improve the capacity for tumour characterisation. Our results suggest that propagation-based phase-contrast region-of-interest CT imaging could enable better tumour visualisation, which may aid in earlier detection and a better outcome for lung cancer patients.