The samples were prepared and measured as described elsewhere . Briefly, samples were cut into lengths of 3 cm along the flow direction and soaked using demineralized water at a w/w ratio of 15:1 (water: sample). The samples were then dried and measured using the Rapid Acquisition with Relaxation Enhancement (RARE) pulse sequence using a field of view of 25 x 20 mm with 39x39x500 µm 3 per voxel resolution on a 600 MHz (14 T) wide-bore spectrometer (Ascend 600WB Avance NEO, Bruker, Germany with a 1.5 T/m imaging gradient system (Micro 2.5, Bruker, Germany)). A quadrature 1 H probe (MicWB40/025 QTR, Bruker, Germany) was used.