Real-time freehand 3D ultrasound imaging

Real-time freehand 3D ultrasound (US) has attracted much attention in clinical practices because it provides interactive feedback to help the clinicians acquire not only high-quality images but also timely information of the scanning area, which is necessary in intraoperative examinations. In this study, we developed a real-time freehand 3D US imaging system which can obtain volume reconstruction and visualisation during data acquisition at real-time level. Based on two popular algorithms, i.e. squared distance weighted interpolation (SDW) and Bezier interpolation, we designed corresponding parallel computing methods that were implemented on the graphics processing unit (GPU) to incrementally reconstruct and display the tissues being scanned using Visualisation toolkits (VTK). With a typical B-scan image size of 302 × 268 at an acquisition rate of 25 Hz and a preset volume size of 90 × 81 × 192, the system achieved an incremental reconstruction-visualisation rate of up to 32 frames/s and 119 frames/s for the SDW and Bezier algorithms, respectively, achieving the real-time 3D US.