Five-dimensional ultrasound system for soft tissue visualization.
OBJECTIVE
A five-dimensional ultrasound (US) system is proposed as a real-time pipeline involving fusion of 3D B-mode data with the 3D ultrasound elastography (USE) data as well as visualization of these fused data and a real-time update capability over time for each consecutive scan. 3D B-mode data assist in visualizing the anatomy of the target organ, and 3D elastography data adds strain information.


METHODS
We investigate the feasibility of such a system and show that an end-to-end real-time system, from acquisition to visualization, can be developed. We present a system that consists of (a) a real-time 3D elastography algorithm based on a normalized cross-correlation (NCC) computation on a GPU; (b) real-time 3D B-mode acquisition and network transfer; (c) scan conversion of 3D elastography and B-mode volumes (if acquired by 4D wobbler probe); and (d) visualization software that fuses, visualizes, and updates 3D B-mode and 3D elastography data in real time.


RESULTS
We achieved a speed improvement of 4.45-fold for the threaded version of the NCC-based 3D USE versus the non-threaded version. The maximum speed was 79 volumes/s for 3D scan conversion. In a phantom, we validated the dimensions of a 2.2-cm-diameter sphere scan-converted to B-mode volume. Also, we validated the 5D US system visualization transfer function and detected 1- and 2-cm spherical objects (phantom lesion). Finally, we applied the system to a phantom consisting of three lesions to delineate the lesions from the surrounding background regions of the phantom.


CONCLUSIONS
A 5D US system is achievable with real-time performance. We can distinguish between hard and soft areas in a phantom using the transfer functions.
Department of Computer Science, The Johns Hopkins University, Baltimore, MD, USA. nishikant@cs.jhu.edu.
Nishikant P
http://orcid.org/0000-0002-9717-5290
NP
Deshmukh
National Intrepid Center of Excellence, Walter Reed National Military Medical Center, Bethesda, MD, USA.
Jesus J
JJ
Caban
Department of Computer Science, The Johns Hopkins University, Baltimore, MD, USA.
Russell H
RH
Taylor
Department of Computer Science, The Johns Hopkins University, Baltimore, MD, USA.
Gregory D
GD
Hager
Department of Computer Science, The Johns Hopkins University, Baltimore, MD, USA.|Department of Radiology, The Johns Hopkins Medical Institutions, Baltimore, MD, USA.
Emad M
EM
Boctor
D000465:Algorithms; D003199:Computer Systems; D054459:Elasticity Imaging Techniques / Q000379:methods*; D005240:Feasibility Studies; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods; D019047:Phantoms, Imaging / Q000592:standards; D012984:Software
3D elastography; 3D scan conversion; Computer graphics; Elastography; Five-dimensional ultrasound system; GPU; Medical imaging; OpenGL; Ultrasound; Visualization