Evidence for the Role of Intracellular Water Lifetime as a Tumour Biomarker Obtained by In Vivo Field-Cycling Relaxometry.

It was established through in vivo T measurements at low magnetic fields that tumour cells display proton T values that are markedly longer than those shown by healthy tissue. Moreover, it has been found that the elongation of T parallels the aggressiveness of the investigated tumour. The T lengthening is associated with an enhanced water exchange rate across the transcytolemmal membrane through an overexpression/upregulation of GLUT1 and Na /K ATPase transporters. It follows that the intracellular water lifetime represents a hallmark of tumour cells that can be easily monitored by measuring T at different magnetic field strengths ranging from 0.2 to 200 mT.