Stephan Strassle Rojas was awarded the best student paper at the 2021 IEEE International Ultrasonics Symposium. The symposium took place virtually from September 11-16, 2021. 

Strassle is a Ph.D. student in the Georgia Tech School of Electrical and Computer Engineering (ECE), and is a member of the Ultrasonic Imaging and Instrumentation (UII) Lab. His advisor is Brooks Lindsey, assistant professor of biomedical engineering and adjunct assistant professor in ECE. Strassle is also a peer instructor at Georgia Tech’s Interdisciplinary Design Commons, commonly known as The Hive. 

The title of Strassle’s award-winning paper is “A Thin, High Penetration Depth Phased Array Transducer with a Metamaterial Acoustic Backing for Cardiac Imaging with X-Ray Computed Tomography Compatibility.” Strassle’s co-authors are Lindsey and Srini Tridandapani, a professor in the Department of Radiology at the University of Alabama at Birmingham. Strassle also credits the invaluable support of fellow lab members of the UII lab, including Bowen Jing, Graham Collins, and Saeyoung Kim. 

Strassle’s work focuses on ultrasound-based cardiac gating and its potential benefits in improving the diagnostic accuracy and reducing radiation dose for non-invasive imaging of coronary artery disease with computed tomography coronary angiography (CTCA) by providing more accurate detection of cardiac quiescence—the time period when cardiac motion is at a minimum—while a patient is undergoing a CT scan of the heart. To achieve this goal, Strassle designed a CT-compatible ultrasound transducer incorporating an acoustic metamaterial within its backing, enabling a thinner transducer with improved CT compatibility. 

Coronary artery disease is one of the leading causes of death globally; however, diagnosis can be challenging and expensive since a cardiac catheterization lab is typically required for catheter coronary angiography (CCA), the gold standard for diagnosing coronary artery disease. Access to a cardiac catheterization lab is particularly scarce in rural areas. CTCA is an alternative, non-invasive diagnostic tool that is lower cost and more accessible but requires effective gating to produce diagnostic-quality scans in all patients.