In the paper we investigate a possibility to perform shape-sensitive HBT analysis in transversal plane. We study presently used Side-Out decomposition of the correlation function and we do not find it to be very sensitive for the detection of a shape of source distribution in transversal plane. Therefore we suggest to use X-Y decomposition of the correlation function for the HBT analysis. We test the method suggested on artificial and non-central Pb-Pb 158GeV/n events produced by CASCUS generator. Further possible enhancement of the method is sketched.