Hossack Laboratory

Hossack Lab is a group of researchers who study ultrasound and ultrasound contrast agents to advance innovative applications in disease diagnosis, treatment, and monitoring. Alumni from Hossack lab have been successful in finding positions as post-docs in leading ultrasound research laboratories and in all big three medical imaging companies (GE, Philips and Siemens) and startup companies.

UPDATE (11/13/17): New NIH grant pending

Hossack Laboratory recently received a top 10% score on a new four-year R01 grant application to investigate catheter-based generation of special-purpose microbubbles for rapid erosion of embolic clots. Venous thromboembolism (VTE), comprising Deep Vein Thrombosis (DVT) and Pulmonary Embolism (PE), results in significant mortality, morbidity, and societal cost. There are approximately 900,000 recurrent, fatal and nonfatal VTE events resulting in 300,000 deaths annually in the US.

With this four-year grant, extendable to five years, Hossack Lab will be supported by two R01s, and thus will have secure funding for the duration of incoming PhD students. Additionally, Hossack Lab receives significant support from two NIH grants to UVA colleagues, Dr. Sasha Klibanov and Dr. Mark Okusa, with projects involving ultrasound molecular imaging and ultrasound-based therapies for ischemia-reperfusion injury, respectively. The lab has also had a highly successful record with smaller grants such as the Coulter Partnership grant, funded by the Coulter endowment to the UVA BME department, investigating the capabilities of ultrasound for breast cancer therapy monitoring. Taken together, Hossack Lab is well-positioned to grow and thrive in the coming years despite the challenging funding environment.

  • Ultrasound Molecular Imaging


    Figure 1. Ultrasound image of a mouse hindlimb tumor with adherent microbubbles on the tumor interior. Microbubble signal was successfully isolated using a decorrelation-based imaging technique developed in Hossack Lab (Herbst, et al. 2017).

    What if doctors could detect atherosclerosis in at-risk patients before arterial plaques ever develop? What if cancer could be detected and treated at the first sign of unregulated cell growth? Ultrasound molecular imaging is a powerful imaging method which utilizes microbubble contrast agents to target and bind disease markers in the blood vessels. While traditional imaging methods detect disease by gross anatomical features, we aim to detect disease on a molecular level. This unprecedented level of imaging sensitivity can not only improve the contrast and clarity of diagnostic images, but significantly improve patient outcomes as physicians make faster, more accurate diagnoses.

    In our lab, we program ultrasound imaging sequences and image processing techniques to improve the contrast and isolation of microbubble signals. Our studies work to advance the field of ultrasound molecular imaging toward rapid clinical adoption.


    Figure 2. Ultrasound images of a mouse hindlimb tumor administered with different quantities of targeted microbubbles (yellow). High-sensitivity contrast imaging techniques were developed in Hossack Lab and shown to detect microbubble adherence in dosages as low as 5×10^4 microbubbles per injection, representing a 20-fold increase in imaging sensitivity (Wang, et al 2016).

  • Microfluidic Production of Microbubbles

    Microbubbles are the most widely used ultrasound contrast agent and can be fabricated in a number of ways, including via sonication, agitation, and microfluidics. As shown below, microfluidic production occurs at the expanding nozzle of a microfluidic device, where precisely controlled gas and liquid streams meet to form microbubbles through a variety of pinch-off mechanisms.

    expandingNozzle_cropped.png ffmd generation_stream0.gif


    Dixon, Ultrasound in Medicine and Biology, 2013

    This method of microbubble production is capable of fabricating microbubbles of uniform size distribution at rates as high as 1 million microbubbles per second. Hossack lab studies the use of the microbubbles as imaging contrast agents and as therapeutic agents for drug delivery and sonothrombolysis.



    Dhanaliwala, Biomedical Microdevices, 2015



    Dixon, Annals of BME, submitted 2017

    We are also investigating the use of this technology in catheter-based applications and are in the process of developing on-chip electrical control and monitoring systems to regulate device operation in real-time.


    Rickel, IUS 2017

  • Photoacoustic Imaging

    The photoacoustic response produces acoustic waves from tissue-specific absorption of light energy. Our lab develops and investigates the properties of photoacoustic contrast agents based on microbubble and perfluorocarbon droplet platforms. As shown below, these contrast agents integrate light absorbing nanoparticles, like gold nanorods (AuNR), on their surface and absorb light energy. The resulting photoacoustic responses are significantly larger and carry unique information, which allows them to be differentiated from photoacoustic signals originating from the surrounding tissue.


    Dixon et al, Small, 2015

    We use high speed cameras to visualize the response of these agents to laser excitation on the nanosecond timescale. As demonstrated in the video, the microbubble expands immediately following laser excitation and relaxes to approximately its original size within 1 microsecond.


    Dixon et al, Small, 2015

    Potential applications of these agents include molecular imaging, tracking of drug-loaded particles, and monitoring the release of drugs from activatable drug carriers. As an example, in the video below, red blood cells were loaded with light absorbing particles, drugs, and perfluorocarbon nanodroplets. These agents rupture when exposed to high intensity ultrasound, thereby releasing the drug locally and dispersing the light absorbing particles. After their dispersion, they will no longer yield a strong photoacoustic response, thereby confirming rupture of the blood cell and local drug delivery.


  • Ultrasound Artifact Reduction


    Echocardiography is frequently used to assess cardiac function. However, getting a diagnostic quality echocardiographic image is often difficult due reflections from the surrounding anatomy and subcutaneous fat. These reflections are super imposed on the moving heart and hinder diagnosis. In the Hossack Lab we develop signal processing methods to eliminate artifacts while retaining the underlying tissue. We confirm that the underlying tissue is retained by wall motion tracking analysis.  

  • John Hossack

    John Hossack

    Principal Investigator jh7fj@virginia.edu

    John A. Hossack received his B.Eng. and Ph.D.  from the University of Strathclyde, Glasgow, UK. Following his PhD, he was a post-doctoral scholar in the E. L. Ginzton Laboratory at Stanford University. He then worked at Acuson, a leading developer of advanced diagnostic ultrasound instrumentation, for seven and half years. During this time, he was recognized as an Acuson Fellow for excellence in technical contribution.  In 2000, he joined the Department of Biomedical Engineering at the University of Virginia. He has been recognized as a Fellow of the IEEE, Fellow of AIMBE and was a 2016 Edlich-Henderson UVa. "Innovator of the Year”. Since 2000, he has been involved with three startup companies: PocketSonics (handheld C-Scan ultrasound resulting in product on market and technology sale), Rivanna Medical (handheld ultrasound spinal imaging with product on market) and SoundPipe Therapeutics (catheter-based ultrasound imaging and drug delivery at prototype / validation stage).

  • Will Mauldin

    Assistant Research Professor fwm5f@virginia.edu

    Will Mauldin received his Ph.D. in Biomedical Engineering from the University of Virginia in 2010. He holds an appointment as an Assistant Research Professor in Biomedical Engineering in Dr. John Hossack’s lab. In this role, Will supports projects involving ultrasound-based targeted molecular imaging and image processing. In addition to his role at the University of Virginia, Will serves as the Chairman & CEO of a company he founded as a graduate student. The company, Rivanna Medical, has commercialized a new medical ultrasound-based anesthesia guidance device, called Accuro.

    Rivanna Medical
  • Adam Dixon

    Adam Dixon

    Research Associate ajd3ng@virginia.edu

    Adam Dixon received his Bachelor’s degree in Biomedical Engineering from Duke University in 2009 and a Ph.D. in Biomedical Engineering from the University of Virginia in 2016. Prior to graduate school, he worked as an engineer in the x-ray/fluoroscopy, computed tomography, and ultrasound imaging businesses at GE Healthcare. Adam is now the Director of Clinical R&D at Rivanna Medical, LLC and continues to perform research in the Hossack lab related to microfluidic production of microbubbles for therapeutic applications and the development of contrast agents for photoacoustic imaging. 

  • Sunil Unnikrishnan

    Sunil Unnikrishnan

    Research Associate su5z@virginia.edu

    Sunil Unnikrishnan is a post-doctoral research associate in the Hossack lab. He received his PhD in Biomedical Engineering from the University of Virginia in 2014. His research involves ultrasound molecular imaging for tumors, and therapy and imaging of large vessels. Outside the lab, Sunil is often spotted at numerous happy hours around Cville.

  • Sushanth Sathyanarayana

    Sushanth Sathyanarayana

    Graduate Student sg6ky@virginia.edu

    Sushanth G. received his Bachelor’s degree in Electrical and computer engineering from RVCE Bangalore, India. He later received his Master’s degree in the same field from the University of Texas at San Antonio. He was excited by medical imaging and ultrasound during his work in industry at Philips Research India in Bangalore, India. His research deals with developing novel signal processing and machine learning methods for artifact reduction and accelerated imaging in ultrasound and photoacoustics. In his spare time, he enjoys traveling, playing and watching sports & computer games and reading.

  • Robert Rickel

    Robert Rickel

    Graduate Student jr3rs@virginia.edu

    Robert Rickel received his Bachelor’s degree in Biomedical Engineering in 2012 and Master’s degree in the same field in 2013 from the University of Michigan. His research involves the integration of electrical sensors into microfluidic devices to sense the microfluidic production of microbubbles for therapeutic applications. In his spare time, Robert enjoys working out, playing ice hockey and watching various sporting events.

  • Elizabeth Herbst

    Elizabeth Herbst

    Graduate Student ebh7em@virginia.edu

    Elizabeth Herbst received her Bachelor’s degree in Biomedical Engineering from the University of Virginia in 2015. Her research incorporates the use of programmed ultrasound sequences and image processing techniques to detect cancer and cardiovascular disease on a molecular level. In her spare time, Elizabeth enjoys going to concerts downtown, cooking with her roommates, and baking sourdough bread.



Elizabeth Herbst

  • William L. Ballard Jr. Endowed Graduate Fellowship, University of Virginia



Elizabeth Herbst

  • Biotechnology Training Grant Appointment, University of Virginia
  • National Science Foundation Honorable Mention, University of Virginia
  • World Molecular Imaging Congress Women in Medical Imaging Network Scholar Award, WMIC
  • World Molecular Imaging Congress Student Travel Stipend, WMIC



John Hossack

  • 2016 Edlich-Henderson UVA Innovator of the Year Award, University of Virginia Licensing and Ventures Group


Sushanth Sathyanarayana

  • 2016 IEEE International Ultrasonics Symposium Travel Award, IEEE IUS


Robert Rickel

  • American Heart Association Predoctoral Fellowship, University of Virginia


Elizabeth Herbst

  • Jefferson Graduate Scholars Fellowship, University of Virginia
  • Virginia Commonwealth Fellowship in Engineering, University of Virginia
  • 2016 IEEE International Ultrasonics Symposium Travel Award, IEEE IUS



John Hossack

  • Fellow of IEEE (Institute of Electrical and Electronics Engineers), IEEE


Adam Dixon

  • 1st Place Student Paper Award, IEEE International Ultrasonics Symposium
  • Oral Presentation Finalist, 20th European Symposium on Ultrasound Contrast Agent Imaging
  • Jill E Hungerford Award (Top Student in Biosciences at UVA), University of Virginia
  • 2015 Most Outstanding BME Graduate Student, University of Virginia
  • 2015 IEEE International Ultrasonics Symposium Travel Award, IEEE IUS



John Hossack

  • Fellow of AIMBE (American Institute for Medical and Biological Engineering), AIMBE


Adam Dixon

  • Double Hoo Research Fellowship, University of Virginia
  • Institutional Nominee to Attend Lindau Nobel Laureate Conference, University of Virginia
  • 2014 IEEE International Ultrasonics Symposium Travel Award, IEEE IUS


Shiying Wang

  • 1st Place Student Paper Award, IEEE IUS
  • Reviewer's Choice Award, BMES


Robert Rickel

  • Cardiovascular Research Center Training Grant Appointment, University of Virginia



Will Mauldin

  • Charlottesville Business Innovation Council (CBIC) Breakthrough of the Year Award, Rivanna Medical 


Adam Dixon

  • Graduate STEM Research Fellowship, Virginia Space Grant Consortium
  • First Place Poster Presentation, 18th European Symposium on Ultrasound Contrast Agent Imaging



Ali Dhaniwala

  • American Heart Association Predoctoral Fellowship, University of Virginia
  • Graduate STEM Fellowship, Virginia Space Grant Consortium
  • Cardiovascular Research Center Training Grant Appointment, University of Virginia


Adam Dixon

  • National Science Foundation Graduate Research Fellowship, University of Virginia
  • American Heart Association Predoctoral Fellowship (declined), University of Virginia