def get_valid_image_ranges(experiments):
    """Extract valid image ranges from experiments, returning None if no scan"""
    valid_images_ranges = []
    for exp in experiments:
        if exp.scan:
            valid_images_ranges.append(exp.scan.get_valid_image_ranges(exp.identifier))
        else:
            valid_images_ranges.append(None)
    return valid_images_ranges