ShEEP Request for Intravascular Ultrasound System

Va San Diego Healthcare System, San Diego CA

Investigators

Abstract

Abstract We are requesting ?Intravascular Ultrasound System (IVUS)? for a group of VA investigators. IVUS has long been used in cardiology and other branches of physiological research for high- resolution intraluminal imaging. It is a unique approach for the evaluation of a wide range of abnormalities within the luminal structures throughout the body by generating tomographic section of the entire length of the luminal cavity. IVUS imaging has been able to obtain information not available with even the most sophisticated percutaneous sonography, CT, or MRI. The uniqueness of this approach has led to a variety of clinical applications. These miniature ultrasound transducer based catheters have played a role in the evaluation of the urinary and gastrointestinal tracts. Currently, a majority of cardiac imaging research techniques have mostly examined the heart using trans-thoracic imaging with ultrasound. We will outline three distinct areas of research where we have significant need for this equipment: 1) cardiology; 2) urology and 3) gastroenterology. Proposed IVUS use is expected to provide more detailed information to be extracted by imaging the heart using a series of tomographic section (from within the heart i.e., from apex to base using a ECG gated pullback) and reconstructing the three dimensional geometry to examine the remodeling of the myocardium during heart failure and during treatment. A single long axis image can be reconstructed using the software built in the IVUS system or many more sections can be created using custom software developed by our group. In addition, we propose to use this system for other important non- vascular intra-luminal investigations including in urethra and anal canal. Because sonographic catheters are smaller than 3mm (3.2 to 9F) in diameter (depending on the imaging frequency: range 9 to 45 MHz), they can be easily passed into the urethra (human and animal model) without the need for dilatation. In addition to thickness, this technique enables the therapeutic injections precisely at the region of the sphincter and to measure the exact depth of the injected material. Transurethral sonography has also been used to assess the deployment of intra- prostatic and intra-sphincter urethral stents. Intra-luminal sonography has been used for imaging urinary bladder neoplasms. Small tumors are clearly identified, and their degree of invasion can be evaluated. Currently, there are no good imaging modalities to assess tumor depth within the urinary bladder. Some urologists use magnetic resonance imaging (MRI) for staging of genitourinary diseases, including bladder cancer. Urologists have been accustomed to ultrasound and continue to use this imaging modality for prostate biopsies. Therefore, the use of transurethral ultrasonography for bladder cancer is more reasonable than any other imaging modality. Proposed equipment will be instrumental in determining the staging of the bladder tumor. In addition, IVUS can help assess the areas and depth of tissue to resect in order to achieve complete resection. This information is important in determining prognosis from bladder cancer, and for appropriate therapeutic interventions. Gastroenterological applications that were developed by Dr. Bhargava have been used for over a decade (see references in bio-sketch) but due to the obsolescence of the older machine a need for the new platform has become imperative. In summary, we anticipate that this equipment will be a significant addition to our research facility and will be jointly used by multiple investigators.