PLUS: open-source toolkit for ultrasound-guided intervention systems

Abstract

A variety of advanced image analysis methods have been under the development for ultrasound-guided interventions. Unfortunately, the transition from an image analysis algorithm to clinical feasibility trials as part of an intervention system requires integration of many components, such as imaging and tracking devices, data processing algorithms, and visualization software. The objective of our paper is to provide a freely available open-source software platform-PLUS: Public software Library for Ultrasound-to facilitate rapid prototyping of ultrasound-guided intervention systems for translational clinical research. PLUS provides a variety of methods for interventional tool pose and ultrasound image acquisition from a wide range of tracking and imaging devices, spatial and temporal calibration, volume reconstruction, simulated image generation, and recording and live streaming of the acquired data. This paper introduces PLUS, explains its functionality and architecture, and presents typical uses and performance in ultrasound-guided intervention systems. PLUS fulfills the essential requirements for the development of ultrasound-guided intervention systems and it aspires to become a widely used translational research prototyping platform. PLUS is freely available as open source software under BSD license and can be downloaded from http://www.plustoolkit.org.

Figure 1

Example of a pipeline for simultaneous acquisition of tracked B-mode and RF image data. B-mode data is used for live display, while RF data is saved to disk.

Figure 2

Tools and associated coordinate systems in a typical tracked US system calibration setup

Figure 3

Example of a pipeline for volume reconstruction.

Figure 4

Example of a pipeline for generating simulated ultrasound data for a tracked probe and needle.

Figure 5

Example of a pipeline for simultaneous acquisition of tracked B-mode and RF image data. B-mode data is used for live display, while RF data is saved to disk.

Figure 6

Software components of the PLUS toolkit. Arrows point to components that another component depends on. All modules depend on the PLUS common component, however the associated arrows are omitted for clarity.

Figure 7

Building 3D Slicer [35] plug-in modules without being directly linked to PLUS, using OpenIGTLink connection.

Figure 8

Screenshot of the 3D Slicer application visualizing the live US image and a tracked needle based on the information that it receives from the PlusServer through OpenIGTLink

Figure 9

Screenshot of the 3D Slicer application visualizing the simulated US image and the corresponding 3D model

Figure 10

A screenshot of brain shift visualization in 3D Slicer using MRI and US volume fusion (Brigham and Women’s Hospital: PI Wells and Aylward, Neurosurgeon Alexandra Golby, NIH Grant R01CA138419 on Image registration for ultrasound-based neurosurgical navigation). PLUS was used for acquiring and reconstructing an US volume and sending the live US image for visualization in 3D Slicer.