John Hossack

Ultrasound is applied to the diagnosis of many different disease conditions: heart conditions, vascular health (e.g. to visualize plaque that may be associated with Stroke), liver and kidney diseases and a variety of high resolution shallow imaging applications - e.g. breast imaging for cancer diagnosis and musculoskeletal areas - wrists, shoulder muscles etc. The work of my group encompasses: 3D Ultrasound, High bandwidth ultrasound, mouse heart imaging, prostate ultrasound and diagnosis of Obstructive Sleep Apnea using ultrasound. 3D Ultrasound We are using a unique image tracking based approach to obtain dimensionally accurate 3D ultrasound images for several applications including: Mouse heart chamber volume assessment and prostate cancer volume assessment. We have also applied the technique to breast cancer.  Transducers In the transducer field, we are primarily working in two areas: 1. High channel count, fully sampled 2D arrays for C-Scan imaging. Currently we are working on 60x60 5 MHz arrays. This work is supported by the NIH NIBIB (EB 02349) 2. We are exploring MEMS silicon micromachined transducers. These transducers have significant potential for enabling high signal bandwidth. This work involves significant finite element analysis and some prototype fabrication work.  Prostate Cancer Detection In this new project we seek to develop a method that combines ultrasonic based anatomical imaging with measurements of tissue elasticity that attempt to replicate and improve upon the conventionally employed digital rectal examination. This work is supported by the Mellon Prostate Cancer Institute and by the US Army CDMRP. Mouse Heart Imaging The mouse is the preferred animal for cardiovascular research. In particular there is interest in tracking the progression of heart tissue response following a myocardial infarction (heart attack).  We are interested in quantifying the volume of the left ventricle through the cardiac cycle and in assessing regional blood perfusion. This work is currently supported by the University of Virginia CVRC. This work is now also supported by the NIH (EB 01826) Microbubbles for Therapeutic Applications Microbubbles, with a size approximately matching that of a red blood cell (or smaller), are being investigated for therapeutic applications - including drug delivery and gene delivery. The University of Virginia has strong research groups active in these areas (in the Cardiovascular Division and within Biomedical Engineering). We collaborate with these groups. Please visit the links to the left and email any questions. Thanks.

Left: 2D tissue tracking applied to high resolution B-Mode image of mouse left ventricle. Uniformity of pumping function in normal and diseased hearts can be assessed. Right: Prototype 60x60 fully sampled 5MHz 2D array for Sonic Window project - low cost C-Scan imaging

Links:

Transducer Finite Element Analysis Virginia Medical Ultrasound Group - with links to related projects, faculty and papers available for download Biomedical Engineering Dept. University of Virginia Home page Brief Bio. Equipment and Facilities External links of interest PZFlex Finite Element Information IEEE Ultrasound page Siemens Ultrasound Group VisualSonics Philips (includes ATL and Agilent (HP) Ultrasound) GE Medical - Ultrasound Vermon Ultrasound Transducers Acknowledgments Several companies have provided significant in-kind assistance at various times. These include: Weidinger Associates Inc., Siemens Medical Solutions, Philips Medical Systems, Vermon, CTS Wireless Ceramics and Tyco-Precision Interconnect

Contact Information: Biomedical Engineering 415 Lane Road, MR5 PO Box 800759 University of Virginia Charlottesville VA 22908-0759

Phone:

(1) 434 243 5866

(1) 434 982 3870

Fax:

hossack *at* virginia.edu