Fig. 4. Hyperpolarised ¹³C-MRI in a case of triple-negative breast cancer (TNBC).

a Coronal T1 3D spoiled gradient echo (SPGR) MRI image. b Coronally reformatted DCE image at peak enhancement after intravenous injection of a gadolinium-based contrast agent. c Summed hyperpolarised ¹³C-pyruvate and d summed hyperpolarised ¹³C-lactate images. The area of low ¹³C-pyruvate and ¹³C-lactate signals in the centre of the tumour are likely to correspond to an area with low enhancement on DCE. e LAC/PYR map showing intratumoural heterogeneity. The dominant intratumoural heterogeneity was concordant between the DCE-MRI and hyperpolarised ¹³C-MRI images and represents decreased delivery of both the gadolinium-based contrast agent and ¹³C-pyruvate to the centre of the tumour. f, g Dynamic hyperpolarised ¹³C-pyruvate and ¹³C-lactate images acquired over 15 time points after intravenous injection of hyperpolarised [1-¹³C]pyruvate (delay = 12 seconds; temporal resolution = 4 seconds). h Top: ¹³C metabolite spectrum from a coronal dynamic IDEAL spiral CSI slice covering the tumour summed over 15 time points; Bottom: The axial image from the equivalent DCE-MRI data was taken at the timepoint of maximum tumour enhancement. ppm parts per million, IC NST invasive cancer of no specific type. This Figure was reproduced from⁴³ (10.1073/pnas.1913841117), licenced under CC-BY-NC-ND (https://creativecommons.org/licenses/by-nc-nd/4.0/).