Based on the diagram it looks like you would like to crop the MRI volume and then resample it.
Are you sure the first step is performed in the model?
If so, I think a simple linear interpolation should yield the results:
slices = 10
channels = 3
height = 24
width = 24
x = torch.randn(channels, slices, height, width)
out = torch.nn.functional.interpolate(x, scale_factor=1.5)

Would that work for you?