Figure 3

Example MRI measurements in SW1222 and LS174T tumors, prior to and at 24 and 72 hours following treatment with Ixazomib, showing increasing amide and amine peak areas, alongside increasing apparent diffusion coefficient (ADC). (a) Z-spectra from CEST MRI, showing the normalised MRI signal intensity as a function of saturation frequency offset, averaged over a single representative tumor dataset at baseline and 24 and 72 hours following dosing with 11 mg kg⁻¹ of Ixazomib. Data points were fitted to a Bayesian model that allowed the individual influence of proton exchange between water and amide, amine and hydroxyl groups to be isolated (1.2, 2.4 and 3.5 ppm, respectively), alongside the combined effect of magnetisation transfer (MT, −2.4 ppm) and nuclear Overhauser effect (NOE, −3.3 ppm). Water peaks (0 ppm) have been removed for clarity. (b) Images of amide, amine hydroxyl, MT and water peak areas, acquired noninvasively in an example SW1222 tumor at baseline and post-therapy (24 and 72 hours). Maps of the apparent diffusion coefficient (ADC) from diffusion MRI measurements and the transverse relaxation time (T₂) are also shown. (c) Representative T₂-weighted (left) and CEST reference images (right).