There is always the need to calculate the response of a layered composite material to a source that is not close to the domain of interest when dealing with the imaging of an anomaly that might be affecting such a background medium. If this medium is anisotropic, the availability of an efficient and accurate method to calculate this response becomes essential. A novel interpolation and integration method that is taking care of fast oscillating spectral response due to a source that is not close to the domain of interest is proposed herein. The implementation of such a technique to the multiple signal classification (MUSIC) imaging method is presented also.