Stradivarius Project: EPSRC Funded 1992-1996

Summary of Objectives and Results

The aim of the Stradivarius project was to investigate techniques and establish a working system for the acquisition of three-dimensional ultrasound data in a clinical environment, and for the reconstruction and visualisation of the data thus acquired.

The primary achievement of the project was to create a real-time, easy-to-use system for three-dimensional clinical ultrasound. This went beyond the scope originally proposed for the project, which only involved an off-line system as a proof of concept. B-scan images are grabbed directly into memory from a Toshiba scanner while the positions and orientations of the scan frames are obtained from a Polhemus proprioceptive device attached to the transducer. A real-time system is not only a huge benefit clinically, but it also enables a simpler system structure and the use of more reliable calibration methods.

A new method for non-invasive clinical volumetry has been developed, which is more accurate than those currently employed as it does not depend on the clinician finding particular organ axes or the organ having geometrically convenient shapes. The technique is based on fitting deformable mesh models to the 3D data and provides a mathematical basis for compensation for organ motion during scanning. The development of an easy-to-use graphical user interface has been an important part of this work. It has been applied to in vivo measurements of thyroids, spleens, prostates, livers and hearts. The system as a whole has also been successfully applied to the reconstruction of subjects' knees, providing a novel method for assessing a variety of genetic and developmental defects without the need for CAT or MRI scans. This is far more accurate than various ad hoc techniques previously used with ultrasound scans.

At an early stage, the important decision was made to network the radiology department to the university and hence to the outside world. Without this much of the project would not have been practical. This will also be invaluable in future medical imaging projects.

The Stradivarius Project provided fertile ground for one undergraduate, one MSc and three PhD students' academic dissertations. A new method has been developed for statistical segmentation of three-dimensional ultrasound data. This is being incorporated into a prototype system for three-dimensional guided needle biopsy. A new algorithm has been produced to compute a reconstruction from contours in many non-parallel planes. This provides the ability to visualise and measure three-dimensional data directly, without casting it into a rectangular grid.

The Stradivarius Project has developed methods of clear commercial utility which will form the basis of a future collaborative research proposal with Zeneca Pharmaceuticals (Manchester).

The Stradivarius Project has provided initial experience of methods of clear clinical utility, leading to the submission and subsequent awarding (700 kECU) of the SOLUS-3D (Standardisation of On-Line Ultrasound Scanning in Three Dimensions) proposal in the European Union's `Biomedicine and Health Research Programme.' The system and the spirit of collaboration between the Engineering Department, the Radiology Department of Addenbrookes Hospital and the Rosie Maternity Hospital developed in Stradivarius will form a corner-stone of this work.

On-line Publications

Our Current Acquisition and Visualisation System for 3D Ultrasound

Our latest Project: High Definition Three-Dimensional Ultrasound