Reproducibility Study of 13C MRI Metabolic Imaging

The reproducibility study was performed on a Siemens Biograph mMR 3T system (Siemens
Healthineers, Erlangen, Germany), using a custom-designed ¹³C clamshell
transmit and dual tuned ¹H/¹³C endorectal, receive-only coil
(RAPID Biomedical GmbH, Rimpar, Germany), alongside a MEDRAD Spectris Solaris EP MR
injection system (MEDRAD, Pennsylvania). All chemicals used in this study were
sourced from Merck (Merck KGaA, Darmstadt, Germany); Merck Life Science UK Limited):
L-LDH from rabbit muscle (SKU 10127876001), 5 ml; β-nicotinamide adenine
dinucleotide(NADH), reduced disodium salt hydrate (SKU N8129), 1 g; phosphate
buffered saline (PBS), pH 7.2, (SKU 806544), 1 L.
Data processing was performed using MATLAB (Mathworks, Massachusetts). Each
metabolite signal time course was normalised to its maximum pyruvate signal,
allowing for different data sets (n = 8) to be compared.
Quantification of the time courses was performed using some previously described methods.^{9 (link)}
These are further explained in the Supplementary Material 1 (Figure S2).