Clinical Utility of Noninvasive Pressure Measurements With SHAPE

The use of gas filled microbubbles (1-10 micron in diameter) as vascular tracers and contrast agents for ultrasound imaging is well established. Such contrast agents are used worldwide to improve the diagnostic capabilities of ultrasound imaging especially when employed in combination with novel nonlinear contrast imaging modes such pulse inversion second harmonic and subharmonic imaging (SHI). Our group produced the first ever human SHI images. We have previously shown that SHI signals can indicate hydrostatic pressures in vitro and has developed a noninvasive pressure measurement technique, known as subharmonic-aided pressure estimation (SHAPE), based on this principle. Noninvasive SHAPE measurements may be a useful alternative to catheter-based measurements of cardiac conditions or portal hypertension. Here, we present results from clinical trials on the utility of SHAPE in patients with heart failure, advanced liver disease (i.e., portal hypertension), or breast cancer (undergoing neoadjuvant chemotherapy). Preliminary SHAPE studies of female incontinence and intracranial pressure measurements will also be presented.