Semiautomatic determination of the reconstruction volume for real-time freehand 3D ultrasound reconstruction

Freehand 3D ultrasound makes use of a 2D ultrasound system and a position sensor to reconstruct 3D ultrasound images. To achieve real-time reconstruction while acquisition, the reconstruction volume must be determined in advance. In this paper, a novel technique is proposed to address the problem effectively. This technique consists of two steps: the interactive selection of the region of interest (ROI), and the automatic determination of the reconstruction volume. The tracked B-scan is used as a vivid tool to explore the target object. After the decision of the principal directions of the target object, four B-scans are designated to enclose the ROI. The reconstruction volume corresponding to the ROI is then figured out automatically according to the four tracked B-scans. The presented technique can fast predetermine a compact reconstruction volume aligned with the best viewing direction. Furthermore, the technique is convenient for the clinician and comfortable for the patient. The efficient and flexible nature of the technique is demonstrated on a real-time freehand system.