Field Cycling Imaging: a novel modality to characterise breast cancer at low and ultra-low magnetic fields below 0.2T

Abstract We propose Field-Cycling Imaging (FCI), a new MRI technology accessing a range of low and ultra-low magnetic fields (2mT to 0.2T), to acquire longitudinal relaxation time over 4 orders of magnitude of field strength, and covering the whole body. FCI obtains the Nuclear Magnetic Relaxation Dispersion (NMRD) profiles of tissues, which probes molecular dynamics at micro- to nanometer scales. We present a prospective study including 10 female patients with breast cancers. Low magnetic fields clearly differentiate tumours from adipose and glandular tissues and discriminates true tumour extent beyond that of conventional imaging, matching the true pathological size of the lesion. Using our FCI prototype, T1 variations at low and ultra-low field discriminate invasive from non-invasive cancers in patients (p < 0.05). To our knowledge, we described the first application of in vivo FCI in breast cancer, demonstrating relevant biomarkers that complement diagnosis of current imaging modalities, non-invasively and without contrast agents.