Texture Analysis of Fractional Water Content Images Acquired during PET/MRI: Initial Evidence for an Association with Total Lesion Glycolysis, Survival and Gene Mutation Profile in Primary Colorectal Cancer

Assessing robustness of quantitative susceptibility-based MRI radiomic features in patients with multiple sclerosis

Multiple Sclerosis (MS) is an autoimmune demyelinating disease characterised by changes in iron and myelin content. These biomarkers are detectable by Quantitative Susceptibility Mapping (QSM), an advanced Magnetic Resonance Imaging technique detecting magnetic properties. When analysed with radiomic techniques that exploit its intrinsic quantitative nature, QSM may furnish biomarkers to facilitate early diagnosis of MS and timely assessment of progression. In this work, we explore the robustness of QSM radiomic features by varying the number of grey levels (GLs) and echo times (TEs), in a sample of healthy controls and patients with MS. We analysed the white matter in total and within six clinically relevant tracts, including the cortico-spinal tract and the optic radiation. After optimising the number of GLs (n = 64), at least 65% of features were robust for each Volume of Interest (VOI), with no difference (p > .05) between left and right hemispheres. Different outcomes in feature robustness among the VOIs depend on their characteristics, such as volume and variance of susceptibility values. This study validated the processing pipeline for robustness analysis and established the reliability of QSM-based radiomics features against GLs and TEs. Our results provide important insights for future radiomics studies using QSM in clinical applications.

Water dynamics in human cancer and non-cancer tissues

Normal-to-malignant transformation is a poorly understood process associated with cellular biomechanical properties. These are strongly dependent on the dynamical behaviour of water, known to play a fundamental role in normal cellular activity and in the maintenance of the three-dimensional architecture of the tissue and the functional state of biopolymers. In this study, quasi-elastic neutron scattering was used to probe the dynamical behaviour of water in human cancer specimens and their respective surrounding normal tissue from breast and tongue, as an innovative approach for identifying particular features of malignancy. This methodology has been successfully used by the authors in human cells and was the first study of human tissues by neutron scattering techniques. A larger flexibility was observed for breast versus tongue tissues. Additionally, different dynamics were found for malignant and non-malignant specimens, depending on the tissue: higher plasticity for breast invasive cancer versus the normal, and an opposite effect for tongue. The data were interpreted in the light of two different water populations within the samples: one displaying bulk-like dynamics (extracellular and intracellular/cytoplasmic) and another with constrained flexibility (extracellular/interstitial and intracellular/hydration layers).