134 research outputs found
A Survey on 3D Ultrasound Reconstruction Techniques
This book chapter aims to discuss the 3D ultrasound reconstruction and visualization. First, the various types of 3D ultrasound system are reviewed, such as mechanical, 2D array, position tracking-based freehand, and untracked-based freehand. Second, the 3D ultrasound reconstruction technique or pipeline used by the current existing system, which includes the data acquisition, data preprocessing, reconstruction method and 3D visualization, is discussed. The reconstruction method and 3D visualization will be emphasized. The reconstruction method includes the pixel-based method, volume-based method, and function-based method, accompanied with their benefits and drawbacks. In the 3D visualization, methods such as multiplanar reformatting, volume rendering, and surface rendering are presented. Lastly, its application in the medical field is reviewed as well
Ultrasound-Augmented Laparoscopy
Laparoscopic surgery is perhaps the most common minimally invasive procedure for many diseases in the abdomen. Since the laparoscopic camera provides only the surface view of the internal organs, in many procedures, surgeons use laparoscopic ultrasound (LUS) to visualize deep-seated surgical targets. Conventionally, the 2D LUS image is visualized in a display spatially separate from that displays the laparoscopic video. Therefore, reasoning about the geometry of hidden targets requires mentally solving the spatial alignment, and resolving the modality differences, which is cognitively very challenging. Moreover, the mental representation of hidden targets in space acquired through such cognitive medication may be error prone, and cause incorrect actions to be performed.
To remedy this, advanced visualization strategies are required where the US information is visualized in the context of the laparoscopic video. To this end, efficient computational methods are required to accurately align the US image coordinate system with that centred in the camera, and to render the registered image information in the context of the camera such that surgeons perceive the geometry of hidden targets accurately. In this thesis, such a visualization pipeline is described. A novel method to register US images with a camera centric coordinate system is detailed with an experimental investigation into its accuracy bounds. An improved method to blend US information with the surface view is also presented with an experimental investigation into the accuracy of perception of the target locations in space
Improving elevation resolution in phased-array inspections for NDT
The Phased Array Ultrasonic Technique (PAUT) offers great advantages over the conventional ultrasound technique (UT), particularly because of beam focusing, beam steering and electronic scanning capabilities. However, the 2D images obtained have usually low resolution in the direction perpendicular to the array elements, which limits the inspection quality of large components by mechanical scanning. This paper describes a novel approach to improve image quality in these situations, by combining three ultrasonic techniques: Phased Array with dynamic depth focusing in reception, Synthetic Aperture Focusing Technique (SAFT) and Phase Coherence Imaging (PCI). To be applied with conventional NDT arrays (1D and non-focused in elevation) a special mask to produce a wide beam in the movement direction was designed and analysed by simulation and experimentally. Then, the imaging algorithm is presented and validated by the inspection of test samples. The obtained images quality is comparable to that obtained with an equivalent matrix array, but using conventional NDT arrays and equipments, and implemented in real time.Fil: Brizuela, Jose David. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Camacho, J.. Consejo Superior de Investigaciones Científicas; EspañaFil: Cosarinsky, Guillermo Gerardo. Comisión Nacional de Energía Atómica; ArgentinaFil: Iriarte, Juan Manuel. Comisión Nacional de Energía Atómica; ArgentinaFil: Cruza, Jorge F.. Consejo Superior de Investigaciones Científicas; Españ
A Simplified 3D Ultrasound Freehand Imaging Framework Using 1D Linear Probe and Low-Cost Mechanical Track
Ultrasound imaging is the most popular medical imaging modality for
point-of-care bedside imaging. However, 2D ultrasound imaging provides only
limited views of the organ of interest, making diagnosis challenging. To
overcome this, 3D ultrasound imaging was developed, which uses 2D ultrasound
images and their orientation/position to reconstruct 3D volumes. The accurate
position estimation of the ultrasound probe at low cost has always stood as a
challenging task in 3D reconstruction. In this study, we propose a novel
approach of using a mechanical track for ultrasound scanning, which restricts
the probe motion to a linear plane, simplifying the acquisition and hence the
reconstruction process. We also present an end-to-end pipeline for 3D
ultrasound volume reconstruction and demonstrate its efficacy with an in-vitro
tube phantom study and an ex-vivo bone experiment. The comparison between a
sensorless freehand and the proposed mechanical track based acquisition is
available online (shorturl.at/jqvX0).Comment: 4 pages, 4 figure
Towards Non-contact 3D Ultrasound for Wrist Imaging
Objective: The objective of this work is an attempt towards non-contact
freehand 3D ultrasound imaging with minimal complexity added to the existing
point of care ultrasound (POCUS) systems. Methods: This study proposes a novel
approach of using a mechanical track for non-contact ultrasound (US) scanning.
The approach thus restricts the probe motion to a linear plane, to simplify the
acquisition and 3D reconstruction process. A pipeline for US 3D volume
reconstruction employing an US research platform and a GPU-based edge device is
developed. Results: The efficacy of the proposed approach is demonstrated
through ex-vivo and in-vivo experiments. Conclusion: The proposed approach with
the adjustable field of view capability, non-contact design, and low cost of
deployment without significantly altering the existing setup would open doors
for up gradation of traditional systems to a wide range of 3D US imaging
applications. Significance: Ultrasound (US) imaging is a popular clinical
imaging modality for the point-of-care bedside imaging, particularly of the
wrist/knee in the pediatric population due to its non-invasive and radiation
free nature. However, the limited views of tissue structures obtained with 2D
US in such scenarios make the diagnosis challenging. To overcome this, 3D US
imaging which uses 2D US images and their orientation/position to reconstruct
3D volumes was developed. The accurate position estimation of the US probe at
low cost has always stood as a challenging task in 3D reconstruction.
Additionally, US imaging involves contact, which causes difficulty to pediatric
subjects while monitoring live fractures or open wounds. Towards overcoming
these challenges, a novel framework is attempted in this work.Comment: 9 Pages, 11 figure
Recommended from our members
Real-Time 4D Ultrasound Mosaicing and Visualization
Intra-cardiac 3D ultrasound imaging has enabled new minimally invasive procedures. Its narrow field of view, however, limits its efficacy in guiding beating heart procedures where geometrically complex and spatially extended moving anatomic structures are often involved. In this paper, we present a system that performs electrocardiograph gated 4D mosaicing and visualization of 3DUS volumes. Real-time operation is enabled by GPU implementation. The method is validated on phantom and porcine heart data.Engineering and Applied Science
3D Quasi-Static Ultrasound Elastography With Plane Wave In Vivo
In biological tissue, an increase in elasticity is often a marker of
abnormalities. Techniques such as quasi-static ultrasound elastography have
been developed to assess the strain distribution in soft tissues in two
dimensions using a quasi-static compression. However, as abnormalities can
exhibit very heterogeneous shapes, a three dimensional approach would be
necessary to accurately measure their volume and remove operator dependency.
Acquisition of volumes at high rates is also critical to performing real-time
imaging with a simple freehand compression. In this study, we developed for the
first time a 3D quasi-static ultrasound elastography method with plane waves
that estimates axial strain distribution in vivo in entire volumes at high
volume rate. Acquisitions were performed with a 2D matrix array probe of 2.5MHz
frequency and 256 elements. Plane waves were emitted at a volume rate of 100
volumes/s during a continuous motorized and freehand compression. 3D B-mode
volumes and 3D cumulative axial strain volumes were successfully estimated in
inclusion phantoms and in ex vivo canine liver before and after a high
intensity focused ultrasound ablation. We also demonstrated the in vivo
feasibility of the method using freehand compression on the calf muscle of a
human volunteer and were able to retrieve 3D axial strain volume at a high
volume rate depicting the differences in stiffness of the two muscles which
compose the calf muscle. 3D ultrasound quasi-static elastography with plane
waves could become an important technique for the imaging of the elasticity in
human bodies in three dimensions using simple freehand scanning
Recommended from our members
Instrument Tracking and Visualization for Ultrasound Catheter Guided Procedures
We present an instrument tracking and visualization system for intra-cardiac ultrasound catheter guided procedures, enabled through the robotic control of ultrasound catheters. Our system allows for rapid acquisition of 2D ultrasound images and accurate reconstruction and visualization of a 3D volume. The reconstructed volume addresses the limited field of view, an inherent problem of ultrasound imaging, and serves as a navigation map for procedure guidance. Our robotic system can track a moving instrument by continuously adjusting the imaging plane and visualizing the instrument tip. The overall instrument tracking accuracy is 2.2mm RMS in position and 0.8◦ in angleEngineering and Applied Science
- …