Fig. 3.

The ¹³C-pyruvate and ¹³C-lactate images acquired following i.v. injection of hyperpolarized [1-¹³C]pyruvate in a patient with TNBC. (A) Coronal T1 3D spoiled gradient echo (SPGR) image. (B) Coronally reformatted DCE image at peak enhancement after i.v. injection of a gadolinium-based contrast agent. (C) Summed hyperpolarized ¹³C-pyruvate and (D) summed hyperpolarized ¹³C-lactate images: area of low ¹³C-pyruvate and ¹³C-lactate signals in the center of the tumor, likely corresponding to an area with low enhancement on DCE. (E) LAC/PYR map showing intratumoral heterogeneity (background removed by thresholding). The dominant intratumoral heterogeneity was concordant between the DCE-MRI and HP ¹³C MRI images and represents decreased delivery of both the gadolinium-based contrast agent and ¹³C-pyruvate to the center of the tumor. (F and G) Dynamic hyperpolarized ¹³C-pyruvate and ¹³C-lactate images acquired over 15 time points after i.v. injection of hyperpolarized [1-¹³C]pyruvate (delay = 12 s; temporal resolution = 4 s).