Christopher J. Burrell

3-D visualisation for the study of arterial disease and tissue characterisation

A novel approach to arterial imaging using ultrasonic data is presented. A catheter-mounted ultrasound probe is used to acquire data from within the arterial lumen. Signals reflected from the vessel wall are manipulated by specially created software in order to recreate a three dimensional model of the arterial segment. Of the available reconstruction strategies, the use of volume elements (voxels) has been selected to create detailed and realistic images. A 2-D image is first formed from a matrix of picture elements (pixels), derived from coordinates obtained from the received ultrasound signal. The 3-D image is then recreated in full voxel space from a series of these 2-D pixel images, using linear interpolation between the 2-D slices. The system has been used to recreate accurate 3-D images of arterial models and post-mortem human arterial specimens.<<ETX>>

Ultrasonic imaging of arterial structures using 3D solid modelling

A new type of vascular imaging system is presented which is designed for use in conjunction with percutaneous transluminal treatment techniques (balloon and laser angioplasty, atherectomy, etc.). Three-dimensional computer models of arterial sections are reconstructed in full volume-element (voxel) space from data acquired using a special-purpose, catheter-mounted ultrasound probe. The system is stand-alone, using commercially available computer hardware and specially created software. The software is equally compatible with source data from other modalities.<<ETX>>

3-D computer visualization of arteries and blood flow-in vitro and in vivo

An extension to previously described work on the representation of arterial structures using three-dimensional solid modeling is presented. Data acquired using a special-purpose catheter-mounted ultrasound probe are used to reconstruct 3-D computer models of arterial sections in vitro and in vivo. The images are reconstructed in full voxel space, which allows powerful software manipulation. Preliminary work on tissue differentiation using arterial models and color coding of the image is included. In addition to 3-D arterial visualization, early work on 3-D flow field representation is presented. It is concluded that the combining 3-D visualization of an artery with the presentation of the associated 3-D flow field will result in significant clinical benefit in the assessment of arterial disease.<<ETX>>

3-D visualization of arterial structures: tissue differentiation techniques

We have previously described a method for the 3-D visualisation of arterial structures using the voxel space approach to three-dimensional solid modelling. The system we use for intra-arterial imaging, in vitro and in vivo, is based on ultrasonic data, acquired with a purpose-built, catheter-mounted ultrasound probe. In this paper, we describe the methods employed for the reconstruction of 3-D models from these 2-D ultrasonic data and present preliminary work on tissue differentiation, using arterial models and colour-coding of the image.

3D characterization of the arterial wall using intravascular ultrasound

The authors consider an application of tissue characterization techniques to images obtained from intravascular ultrasound. Three methods are considered, frequency tracking based on advanced spectral estimators, tissue characterization by edge detection, and characterization by textural analysis. A computer-based imaging system was developed that uses a multi-element catheter-mounted ultrasound probe. The system is capable of reconstructing three-dimensional models of arterial structures, which may be manipulated by computer software. The 3-D imaging capability allows a much more detailed analysis of complex stenoses and arterial lesions. An example of the results of this procedure is illustrated.<<ETX>>

3-D blood flow visualization

In this paper, we show how 3-D arterial visualisations may be combined with a 3-D representation of blood flow. We have developed techniques for the estimation and representation of the entire 3-D flow field for the section of artery under investigation. The flow fields are calculated from numerical solutions of the Navier-Stokes equations by a flow solver using a finite difference approach. In order to achieve this, both the profile of the inlet velocity waveform and the shape of the external grid structure of the flow field, derived from the 3-D solid model, are required. Clinically useful 3-D flow information is presented effectively by using a combination of 2-D cross-sectional displays.

Angioplasty under ultrasound

In this paper, we discuss some of the problems associated with attempting to image blood vessels using ultrasound from an intravascular approach. These include device miniaturisation, ultrasonic problems, difficulties with positioning and orientation of the device, and problems associated specifically with imaging catheters incorporating mechanically rotating parts. Some of the possible solutions are suggested, in terms of modification of transducer design, which may ultimately allow us to realise the goal of directing intraluminal treatment devices by means of intravascular, ultrasonic imaging.

3-D Visualization of Arterial Structures and Flow Phenomena

In this chapter we describe the reconstruction of arterial structures using three-dimensional solid modelling. The alternative approaches to three dimensional modelling are discussed and the voxel space system we use for intra-arterial imaging, based on ultrasonic data, is described. The data, acquired with a purpose-built, catheter-mounted ultrasound probe, is used to recreate 3-D computer models of arterial sections in vitro and in vivo. Examples to illustrate the power and flexibility of voxel space modelling in terms of post-processing and software manipulation are given. Preliminary work on tissue differentiation, using arterial models and colour-coding of the image is included. In addition to 3-D arterial visualization, we present early work on theoretical three dimensional flow field representation.