Figure 1.

Multimodal imaging workflow (A) and addressed metabolic pathways (B). Dynamic 90 min PET acquisition was started with tail-vein injection of [¹⁸F]FDG. Simultaneously, magnetic resonance-based attenuation correction ultra-short echo time (MRAC UTE), 3D and 2D T₁- and T₂-weighted proton MRI for determination of tumor localization and slice positioning of ¹³C and DWI acquisition were performed. Dynamic ¹³C-MRSI was measured after injection of HP pyruvate at the end of the PET scan (70-90 min after FDG injection). DWI was performed after PET acquisition. Metabolic parameters (glucose uptake and LDH activity) and structural parameters (tumor cellularity) that were addressed with PET, MRSI and DWI are given in bold. Acquisition times are indicated with black solid lines. Acquisition parameters for proton MRI can be found in the supplement (Table S1). Metabolic pathways (B) that were addressed with FDG-PET and ¹³C-MRSI are colored in red and blue, respectively. Note that arrows with bigger fonts indicate an increased metabolic flux as observable for various tumors.