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Rusty Starr

Research Manager






Mr. Starr's early research experience started with the birth of interventional radiology at Johns Hopkins University and Medical Center. He was involved in investigations of vascular clotting materials with an emphasis on hemostasis of hemorrhaging trauma and bleeding due to vascular anomalies and disease. During these studies he helped develop the Becton Dickenson mini-detachable vascular balloon system used to block bleeding vessels and to ablate tumor vascular supply. Other areas of research involved tumor models and super selective catheterization of tumor feeding arteries for the direct delivery of chemotherapeutic agents, and drug and physiology studies utilizing radiographic imaging and vascular catheterization techniques.

Research at the UW continued along the same lines as those at Hopkins, but also expanded to include other imaging modalities such as ultrasound, magnetic resonance imaging (MRI), and computerized axial tomography (CAT). He joined the APL-UW CIMU research group in 2001 and continues hemostasis research.


2000-present and while at APL-UW

Evaluation of renal stone comminution and injury by burst wave lithotripsy in a pig model

Maxwell, A.D., Y.-N. Wang, W. Kreider, B.W. Cunitz, F. Starr, D. Lee, Y. Nazari, J.C. Williams Jr., M.R. Bailey, and M.D. Sorensen, "Evaluation of renal stone comminution and injury by burst wave lithotripsy in a pig model," J. Endourol., 33, doi:10.1089/end.2018.0886, 2019.

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15 Oct 2019

Burst wave lithotripsy is an experimental technology to noninvasively fragment kidney stones with focused bursts of ultrasound (US). This study evaluated the safety and effectiveness of specific lithotripsy parameters in a porcine model of nephrolithiasis.

A 6- to 7-mm human kidney stone was surgically implanted in each kidney of three pigs. A burst wave lithotripsy US transducer with an inline US imager was coupled to the flank and the lithotripter focus was aligned with the stone. Each stone was exposed to burst wave lithotripsy at 6.5 to 7 MPa focal pressure for 30 minutes under real-time image guidance. After treatment, the kidneys were removed for gross, histologic, and MRI assessment. Stone fragments were retrieved from the kidney to determine the mass comminuted to pieces <2 mm.

On average, 87% of the stone mass was reduced to fragments <2 mm. In three of five treatments, stones were completely comminuted to <2-mm fragments. In two of five treatments, stones were partially disintegrated, but larger fragments remained. One stone was not treated because no suitable acoustic window was identified. No injury was detected through gross, histologic, or MRI examination in the parenchymal tissue, although petechial damage and surface erosion were identified on the urothelium of the collecting system limited to the area around the stone.

Burst wave lithotripsy can consistently produce stone fragments small enough to spontaneously pass by transcutaneous administration of US pulses. The data suggest that such exposures produce minimal injury to the kidney and urinary tract.

An in vivo demonstration of efficacy and acute safety of burst wave lithotripsy using a porcine model

Wang, Y.-N., W. Kreider, C. Hunter, B.W. Cunitz, J. Thiel, F. Starr, J.C. Dai, Y. Nazari, D. Lee, J.C. Williams, M.R. Bailey, and A.D. Maxwell, "An in vivo demonstration of efficacy and acute safety of burst wave lithotripsy using a porcine model," Proc. Mtgs. Acoust., 35, 02009, doi:10.1121/2.0000975, 2018.

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5 Nov 2018

Proceedings, 176th Meeting of the Acoustical Society of America, 5-9 November 2018, Victoria, BC, Canada.

Burst wave lithotripsy (BWL) is a new non-invasive method for stone comminution using bursts of sub-megahertz ultrasound. A porcine model of urolithiasis and techniques to implement BWL treatment has been developed to evaluate its effectiveness and acute safety. Six human calcium oxalate monohydrate stones (6–7 mm) were hydrated, weighed, and surgically implanted into the kidneys of three pigs. Transcutaneous stone treatments were performed with a BWL transducer coupled to the skin via an external water bath. Stone targeting and treatment monitoring were performed with a co-aligned ultrasound imaging probe. Treatment exposures were applied in three 10-minute intervals for each stone. If sustained cavitation in the parenchyma was observed by ultrasound imaging feedback, treatment was paused and the pressure amplitude was decreased for the remaining time. Peak negative focal pressures between 6.5 and 7 MPa were applied for all treatments. After treatment, stone fragments were removed from the kidneys. At least 50% of each stone was reduced to <2 mm fragments. 100% of four stones were reduced to <4 mm fragments. Magnetic resonance imaging showed minimal injury to the functional renal volume. This study demonstrated that BWL could be used to effectively fragment kidney stones with minimal injury.

Effect of carbon dioxide on the twinkling artifact in ultrasound imaging of kidney stones: A pilot study

Simon, J.C., Y.-N. Wang, B.W. Cunitz, J. Thiel, F. Starr, Z. Liu, and M.R. Bailey, "Effect of carbon dioxide on the twinkling artifact in ultrasound imaging of kidney stones: A pilot study," Ultrasound Med. Biol. 43, 877-883, doi:10.1016/j.ultrasmedbio.2016.12.010, 2017.

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1 May 2017

Bone demineralization, dehydration and stasis put astronauts at increased risk of forming kidney stones in space. The color-Doppler ultrasound "twinkling artifact," which highlights kidney stones with color, can make stones readily detectable with ultrasound; however, our previous results suggest twinkling is caused by microbubbles on the stone surface which could be affected by the elevated levels of carbon dioxide found on space vehicles. Four pigs were implanted with kidney stones and imaged with ultrasound while the anesthetic carrier gas oscillated between oxygen and air containing 0.8% carbon dioxide. On exposure of the pigs to 0.8% carbon dioxide, twinkling was significantly reduced after 9–25 min and recovered when the carrier gas returned to oxygen. These trends repeated when pigs were again exposed to 0.8% carbon dioxide followed by oxygen. The reduction of twinkling caused by exposure to elevated carbon dioxide may make kidney stone detection with twinkling difficult in current space vehicles.

More Publications

Acoustics Air-Sea Interaction & Remote Sensing Center for Environmental & Information Systems Center for Industrial & Medical Ultrasound Electronic & Photonic Systems Ocean Engineering Ocean Physics Polar Science Center