Projects

Pressure measurement is an effective, low-risk way of assessing the heath of an organ, and is especially useful in the heart and liver for assessing the risk of cardiac disease and portal hypertension, respectively. Typically, this is done by inserting a catheter into an incision in a patient’s thigh and then passing the catheter through an artery all the way to the heart or liver.

However, Jefferson researchers have devised a way to use CEUS to take measurements with nothing more invasive than the standard microbubble injection. After the bubbles have entered the bloodstream, physicians wait briefly to let the bubbles circulate, while an ultrasound beam is directed at either the heart or liver. As the bubbles pass through the beam, they expand and contract in a predictable way in response to the sonic field. These expansions and contractions are modulated by the pressure in the organ—greater expansion means less pressure, while less expansion often indicates greater organ pressure and an increased likelihood of disease.

Project Contacts:

• Jaydev Dave, PhD
  
• Flemming Forsberg, PhD
• Kibo Nam, PhD
  

Many solid tumors are now being treated using minimally invasive techniques. Liver tumors can be treated via chemoembolization, the standard of care for patients with locally advanced hepatocellular carcinoma. This therapy involves depositing chemo-eluting beads into the blood vessels that feed the tumor or liver lesion in order to provide treatment as directly as possible. The impact is usually measured after 4-6 weeks using contrast-enhanced MRI. Similarly, renal cell cancers are now routinely treated by ablating the tumor using either heat or freezing techniques.

CEUS provides an easy and minimally invasive means of assessing the outcome of these procedures. The physical properties of the bubbles make them ideal for highlighting blood vessels and the structures they supply. Because it does not require any form of radioactivity, it is possible to provide imaging follow-up as frequently as every day should it ever be deemed clinically necessary. Additionally, the microbubbles are not hazardous to patients with decreased kidney function, making them a safer alternative to MRI or CT follow-up. More advanced work is also being done on the use of real time volumetric, or 4D, CEUS to better evaluate such patients.

Project Contacts: 

• John Eisenbrey, PhD
• Colette Shaw, MD
• Andrej Lyshchik, MD, PhD

When a cancer metastasizes, it can spread through the lymphatic system. A sentinel lymph node is the node whose proximity to a malignant area makes it most likely to first come into contact with potential cancer metastases. The ability to assess the state of sentinel lymph nodes gives physicians’ vital information about potentially spreading malignancies.

The standard diagnostic method involves using dye or radioisotopes to observe the flow of lymph channels away from an area of clinical concern. However, these approaches require hours of preparation before a biopsy is performed, while physicians have only a narrow window to observe the relevant structures before the dye or isotope has spread too far.

Our researchers have devised a novel technique enabling them to use microbubble contrast to survey the lymph nodes in animal models. CEUS allows for a greater window of observation without the wait time of other biopsy methods. It also allows physicians to obtain detailed anatomical information without the open surgery required by the dye method. Additionally, our investigators have found that contrast bubbles are more stable in the body, which extends the time a study can be carried out and ultimately allows physicians to obtain better results.

Project Contacts: 

• Flemming Forsberg, PhD
• Ji-Bin Liu, MD

The appearance of prostate cancer on ultrasound imaging is similar to that of the normal tissue, potentially complicating the kind of precision-imaging that makes minimally invasive intervention possible. CEUS enables physicians to get a clear picture of the prostate, and to clearly distinguish malignancies from benign or “normal” structures.

Project Contacts:

• Flemming Forsberg, MD
• Ethan Halpern, MD

The High-Frequency Ultrasound Imaging Division operates a Vevo 2100 high frequency, small animal, ultrasound imaging scanner (Visualsonics, Toronto, Ontario, Canada) with unique high frequency transducers (spanning frequencies from 24 to 70 MHz) in order to support many NIH-sponsored research projects within Thomas Jefferson University (TJU) and the Kimmel Cancer Center (KCC) as well as the Center for Translational Medicine (CTM).  In particular the new instrument is equipped to provide 3D imaging, non-linear contrast imaging, color and tissue Doppler imaging as well as strain rate imaging modes that were not previously available to researchers at TJU and KCC.  The Division also runs a Vevo LAZR system (Visualsonics), which provides photoacoustic imaging capabilities in conjunction with the Vevo 2100.  Photoacoustic imaging provides high optical contrast co-registered with high-resolution ultrasound imaging in real-time (at depths up to 1 cm and axial resolution down to 45 µm) using a 20 Hz tunable laser (680 - 970 nm). 

The Vevo 2100 represents a major upgrade for the small animal imaging capabilities of NIH-funded investigators at both TJU and KCC and has provided state-of-the-art, high resolution, real-time, live animal imaging in their research studies.  Our current “critical mass” in the fields of cancer biology, cardiac biology and vascular pathology will continue to build upon their success with this advanced Vevo 2100 imaging system.  Moreover, emerging studies at the Small Animal Imaging Facility on neuroscience will also benefit from this unique and powerful piece of equipment.  Additionally, the Vevo LAZR system is a new imaging modality for the entire region and will provide not only TJU and KCC investigators but also researchers throughout the city of Philadelphia and the surrounding area with access to a novel tool for small animal imaging in cancer and cardiac biology as well as vascular pathology.  These three disease areas for which the Vevo 2100 system is best equipped with specific applications encompass the major strategic research initiatives of TJU and thus, are well aligned with the Institution’s long-range biomedical research goals.

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Project Contacts:

• Flemming Forsberg, PhD
• Shey-Shing Sheu, PhD