def to_scanner(self, x, y, z):
        """
        Converts a 3d position in MRSData space to the scanner reference frame

        :param x:
        :param y:
        :param z:
        :return:
        """
        if self.transform is None:
            raise ValueError("No transform set for MRSData object {}".format(self))

        transformed_point = self.transform * numpy.matrix([x, y, z, 1]).T

        return numpy.squeeze(numpy.asarray(transformed_point))[0:3]