Tumour T1 changes in vivo are highly predictive of response to chemotherapy and reflect the number of viable tumour cells – a preclinical MR study in mice

Background Effective chemotherapy rapidly reduces the spin–lattice relaxation of water protons (T1) in solid tumours and this change (ΔT1) often precedes and strongly correlates with the eventual change in tumour volume (TVol). To understand the biological nature of ΔT1, we have performed studies in vivo and ex vivo with the allosteric mTOR inhibitor, everolimus.