Texture‐based morphometry in relation to apolipoprotein ε4 genotype, ageing and sex in a midlife population by Dounavi, M, Mak, E, Operto, G, Muniz‐Terrera, G, Bridgeman, K, Koychev, I, Malhotra, P, Naci, L, Lawlor, B, Su, L, Falcon, C, Ritchie, K, Ritchie, CW, Gispert, JD, O'Brien, JT