Blood flow imaging in brain and diagnosis of injuries under the skull remains a challenging problem since in most emergency cases such as a battlefield, ambulance or clinic, there is no MRI or CT scanner to make an urgent decision. In this paper we show that not only the frequency contents of the ultrasound signals but also the resonance components of ultrasound A-scans may need to be taken into consideration to construct high-resolution blood flow images through the skull using ultrasound. Several experiments have been carried out using various custom skull phantoms to match the ultrasonic properties of the human skull including a diploe layer and undulating inner surface. The results indicate a significant improvement in terms of accuracy and computational cost.