With this new approach assessing scaffold perfusion, we determined that denser cryogels have more resistance allowing liquids to pass through, particularly at high flow rates. To further validate the capabilities of MRI to study perfusion, we tested cryogels with a different CMC % (w/w), modifying their stiffness, density and porosity. Concretely, we made and tested cryogels with 0.5%, 1%, 2% and 5 % of CMC. The initial tests, done at a flow rate of 1 mL/min, indicated perfusion issues only with the 5 % CMC cryogel. We show these issues in Fig. , where there is still water proton signal at the bottom of the well (B ROI) after injecting D 2 O, where the scaffold's percentage of CMC is raising from left to right. The horizontal pixel sum (Fig. ) clearly evidenced this fact, showing signal in the bottom region after injection of the contrast agent. We indicate the results for three different flow rates in Fig. , where the 5 % CMC cryogel only fully ejected its contained water at the lowest flow rate (i.e. 0.1 mL/min). We hypothesised that this phenomenon happened due to higher porous resistance at high flow rates in a much denser, stiffer and less porous scaffold. This lower perfusivity also happened if we stacked two 1 % CMC cryogels in one same well, as shown in Fig. , indicating that the scaffold disposition and fluid resistance also plays an important role. We back up this assumption by also reducing the flow rate in this case to 0.1 mL/min, where again there is a significant increase in perfusion efficacy as indicated in Fig. . Hence, MRI and D 2 O as contrast agent seems adequate to determine the perfusion efficiency of scaffolds of different stiffness, densities and porosities uncovering some fluidic issues potentially caused by high resistances.