An open-source real-time ultrasound reconstruction system for four-dimensional imaging of moving organs

Danielle Pace,David Gobbi,Jonathan Boisvert,Terry Peters,Junichi Tokuda,Nobuhiko Hata,Chris Wedlake,Jan Gumprecht

doi:10.54294/sepo1s

Abstract

Four-dimensional imaging is a necessary step in computer-assisted interventions (CAI) performed on moving surgical targets, such as those located within the beating heart or influenced by respiratory motion. Ultrasound (US) is often the best imaging modality for this application, as it provides good contrast and spatial resolution while remaining simple to integrate into the operating room. However, conventional 2D US imaging is often insufficient for preoperative planning and surgical guidance, real-time 3D ultrasound imaging using matrix array probes has a smaller field of view and lower spatial resolution, and 3D volumes created using 3D US reconstruction suffer from motion artifacts. As an alternative, gated 4D ultrasound reconstruction using a tracked 2D US probe is a promising technology. In this paper, we present SynchroGrab4D to the open-source community. SynchroGrab4D performs 3D and 4D US reconstruction in real-time while visualizing the output volume(s) within an OpenIGTLink-compliant CAI system, such as 3D Slicer. Also included are VTK classes that perform ECG-gating and that interface with several commercial tracking systems, as well as a 4D Imaging module in 3D Slicer. Our open-source imaging system can be used to collect the 4D image data required for computer-assisted surgical planning and intraoperative guidance for a variety of moving organs.

Highlights

Initial development of computer-assisted intervention (CAI) systems focused on the orthopaedic and neurosurgical fields, since assuming that the organ of interest is a rigid body made superimposing preoperative images onto the intraoperative patient much simpler
Two alternatives exist for volumetric US imaging of moving organs: real-time 3D (RT3D) ultrasound imaging with a matrix array probe [12] and performing gated 4D ultrasound reconstruction by tracking a standard 2D US probe. 4D US reconstruction extends the well-established 3D US reconstruction technique [3] and generates a time-series of 3D US volumes by using gating to collect multiple 2D US frames acquired at the same point in the organ’s motion cycle and compositing them into 3D volumes using the probe’s pose as measured by the tracking system
As our real-time 3D US reconstruction approach has been previously described [5, 2], here we focus on 4D reconstruction

Summary

Introduction

Initial development of computer-assisted intervention (CAI) systems focused on the orthopaedic and neurosurgical fields, since assuming that the organ of interest (whether a bony structure or the brain encased within the skull) is a rigid body made superimposing preoperative images onto the intraoperative patient much simpler. Some highly-specialized open-source software can perform both non-gated and gated ultrasound reconstruction, including the well-known Stradx system [14], but usually cannot perform subsequent image registration, segmentation, advanced visualization (such as volume rendering) or data transfer for integration into surgical guidance systems. We present SynchroGrab4D, open-source software for the interactive acquisition and visualization of reconstructed 3D and 4D ultrasound data using 3D Slicer.

Results

Conclusion