Fast hybrid freehand ultrasound volume Reconstruction

The volumetric reconstruction of a freehand ultrasound sweep, also called compounding, introduces additional diagnostic value to the ultrasound acquisition by allowing 3D visualization and fast generation of arbitrary MPR(Multi-Planar-Reformatting) slices. Furthermore reconstructing a sweep adds to the general availability of the ultrasound data since volumes are more common to a variety of clinical applications/systems like PACS. Generally there are two reconstruction approaches, namely forward and backward with their respective advantages and disadvantages. In this paper we present a hybrid reconstruction method partially implemented on the GPU that combines the forward and backward approaches to efficiently reconstruct a continuous freehand ultrasound sweep, while ensuring at the same time a high reconstruction quality. The main goal of this work was to significantly decrease the waiting time from sweep acquisition to volume reconstruction in order to make an ultrasound examination more convenient for both the patient and the sonographer. Testing our algorithm demonstrated a significant performance gain by an average factor of 197 for simple interpolation and 84 for advanced interpolation schemes, reconstructing a 2563 volume in 0.35 seconds and 0.82 seconds respectively.