def return2DslicesAsList(scan, plane):
    """
    Takes in a 3D Scan and returns slices as a list along
    axis defined by plane. 
    plane = 'yz' , 'zx', 'xy'
    """
    slices = []
    if plane == "yz":
        for i in range(scan.shape[0]):
            slices.append(scan[i, :, :])
    if plane == "zx":
        for i in range(scan.shape[1]):
            slices.append(scan[:, i, :])
    if plane == "xy":
        for i in range(scan.shape[2]):
            slices.append(scan[:, :, i])
    return slices