Biography

My research central theme is ultrasound and microbubbles and their applications for imaging and therapy. We develop ultrasound imaging techniques to image and quantify blood flow in the microcirculation. These techniques are based on the nonlinear oscillations of microbubbles that result from exposure to ultrasound. We can detect and characterize tumors based on their microvascular patterns while we also develop quantitative techniques to monitor the outcomes of therapies targeting angiogenesis. Clinical applications include liver, breast, kidney and prostate cancer.

Microbubbles are also used in the area of atherosclerosis. With signal and image processing approaches we are trying to establish plaque neovascularization as an atherosclerosis imaging biomarker.

Another area of research is ultrasound-mediated drug delivery. Drugs may be selectively delivered in spatially controlled areas under image-guidance with either temperature or pressure stimuli generated by ultrasound. The interaction of ultrasound and microbubbles in-vivo is utilized in a process called sonoporation which is the transient and reversible cell membrane permeability change. We study the physical mechanisms of sonoporation and the interactions of ultrasound-driven microbubbles with the capillaries and the cells in order to improve drug uptake.
Our research activities span from in-vitro experiments in tissue phantoms to clinical trials with patients. One unique research tool of the Averkiou lab is the ex-vivo machine perfused (MP) pig liver phantom. MP functions as an artificial body with a wholly- or partially-artificial blood supply to sustain an isolated organ (typically from slaughterhouse animals) ex-vivo. MP presents a very promising platform for quantification of blood flow in the microcirculation which is a key element in cancer therapy monitoring. MP is also a test bed for therapeutic applications of ultrasound, such as ultrasound mediated drug delivery, and thermal ablation.

Education

• Ph.D., Mechanical Engineering, The University of Texas at Austin, 1994
• M.S., Mechanical Engineering, The University of Texas at Austin, 1989
• B.S., Mechanical Engineering, The University of Texas at Austin, 1987

Previous appointments

• Postdoctoral Fellow, Applied Physics Laboratory, University of Washington, 1994-1995

Select publications

1. Averkiou MA, Keravnou C, Izamis ML, Leen E. Evaluation of perfusion quantification methods with ultrasound contrast agents in a machine-perfused pig liver. Ultraschall Med. 2016 May; [Epub ahead of print]
2. Christofides D, Leen E, Averkiou M. Evaluation of the accuracy of liver lesion DCEUS quantification with respiratory gating. IEEE Trans Med Imaging. 2016 Feb;35(2):622-9.
3. Keravnou CP, Izamis ML, Averkiou MA. Method for Estimating the Acoustic Pressure in Tissues Using Low-Amplitude Measurements in Water. Ultrasound Med Biol. 2015 Nov;41(11):3001-12.
4. Keravnou C, Mannaris C, Averkiou MA. Accurate measurement of microbubble response to ultrasound with a diagnostic ultrasound scanner. IEEE Trans Ultrason Ferroelectr Freq Control., 2015 Jan; 62(1):176-84.
5. Powers J, Averkiou M. Principles of cerebral ultrasound contrast imaging. Front Neurol Neurosci. 2015;36:1-10.
6. Izamis ML, Efstathiades A, Keravnou C, Georgiadou S, Martins PN, Averkiou MA. Effects of air embolism size and location on porcine hepatic microcirculation in machine perfusion. Liver Transpl. 2014 May;20(5):601-11.
7. Keravnou CP, Averkiou MA. Harmonic generation with a dual frequency pulse. J Acoust Soc Am. 2014 May;135(5):2545-52.
8. Izamis ML, Efstathiades A, Keravnou C, Leen EL, Averkiou MA. Dynamic contrast-enhanced ultrasound of slaughterhouse porcine livers in machine perfusion. Ultrasound Med Biol. 2014 Sep;40(9):2217-30.
9. Christophides D, Leen E, Averkiou MA. “Automatic Respiratory Gating for Contrast Ultrasound Evaluation of Liver Lesions.” IEEE Trans Ultrason Ferroelectr Freq Control. 2014 Jan; 61(1): 25-32. (front cover image)
10. Mannaris C, Efthymiou E, Meyre ME, Averkiou MA. In vitro localized release of thermosensitive liposomes with ultrasound-induced hyperthermia. Ultrasound Med Biol. 2013 Nov;39(11):2011-20.
11. Escoffre JM, Mannaris C, Geers B, Novell A, Lentacker I, Averkiou M, Bouakaz A. Doxorubicin liposome-loaded microbubbles for contrast imaging and ultrasound-triggered drug delivery. IEEE Trans Ultrason Ferroelectr Freq Control. 2013 Jan;60(1):78-87.
12. Dietrich CF, Averkiou MA, Correas JM, Lassau N, Leen E, Piscaglia F. An EFSUMB introduction into Dynamic Contrast-Enhanced Ultrasound (DCE-US) for quantification of tumour perfusion. Ultraschall Med. 2012 Aug;33(4):344-51. Epub 2012 Jul 27.
13. Mannaris C, Averkiou MA. Investigation of microbubble response to long pulses used in ultrasound-enhanced drug delivery. Ultrasound Med Biol. 2012 Apr;38(4):681-91.
14. Leen E, Averkiou M, Arditi M, Burns P, Bokor D, Gauthier T, Kono Y, Lucidarme O. Dynamic contrast enhanced ultrasound assessment of the vascular effects of novel therapeutics in early stage trials. Eur Radiol. 2012 Jul;22(7):1442-50.
15. Thapar A, Shalhoub J, Averkiou M, Mannaris C, Davies AH, Leen EL. Dose-dependent artifact in the far wall of the carotid artery at dynamic contrast-enhanced US. Radiology. 2012 Feb;262(2):672-9.
16. Strouthos C, Lampaskis M, Sboros V, McNeilly A, Averkiou M. Indicator dilution models for the quantification of microvascular blood flow with bolus administration of ultrasound contrast agents. IEEE Trans Ultrason Ferroelectr Freq Control. 2010 Jun;57(6):1296-310.
17. Lampaskis M, Averkiou M. Investigation of the relationship of nonlinear backscattered ultrasound intensity with microbubble concentration at low MI. Ultrasound Med Biol. 2010 Feb;36(2):306-12.
18. Averkiou M, Lampaskis M, Kyriakopoulou K, Skarlos D, Klouvas G, Strouthos C, Leen E. Quantification of tumor microvascularity with respiratory gated contrast enhanced ultrasound for monitoring therapy. Ultrasound Med Biol. 2010 Jan;36(1):68-77.
19. Leen E, Kumar S, Khan SA, Low G, Ong KO, Tait P, Averkiou M. Contrast-enhanced 3D ultrasound in the radiofrequency ablation of liver tumors. World J Gastroenterol. 2009 Jan 21;15(3):289-99.
20. Bruce M, Averkiou M, Tiemann K, Lohmaier S, Powers J, Beach K. Vascular flow and perfusion imaging with ultrasound contrast agents. Ultrasound Med Biol. 2004 Jun;30(6):735-43.
21. Averkiou M, Powers J, Skyba D, Bruce M, Jensen S. Ultrasound contrast imaging research. Ultrasound Q. 2003 Mar;19(1):27-37.
22. Averkiou MA. Tissue harmonic ultrasonic imaging. Comptes Rendus de l’Academie des Sciences – Series IV: Physics, Astrophysics. 2001;2(8):1139-51.
23. Burns PN, Hope Simpson D, Averkiou MA. Nonlinear imaging. Ultrasound Med Biol. 2000 May;26 Suppl 1:S19-22.
24. Averkiou MA, Cleveland RO. Modeling of an electrohydraulic lithotripter with the KZK equation. J Acoust Soc Am. 1999 Jul;106(1):102-12.
25. Becher H, Tiemann K, Schlosser T, Pohl C, Nanda NC, Averkiou MA, Powers J, Lüderitz B. Improvement in Endocardial Border Delineation Using Tissue Harmonic Imaging. Echocardiography. 1998 Jul;15(5):511-518.
26. Averkiou MA, Hamilton MF. Nonlinear distortion of short pulses radiated by plane and focused circular pistons. J Acoust Soc Am. 1997 Nov;102(5 Pt 1):2539-48.
27. Averkiou MA, Lee YS, and Hamilton MF. Self demodulation of amplitude and frequency modulated pulses in a viscous fluid. J. Acoust. Soc. Am. 1993; 94, 2876-2883.

Honors & awards

• European Commission, Marie Curie Chair of Excellence, 2006-2009
• Philips Medical Systems, Engineering Excellence Award, 1997, 1999, 2000
• ATL Ultrasound, Technical Fellow Award, for developing Tissue Harmonic Imaging, 1998
• Institute of Electrical and Electronics Engineers (IEEE) Senior Member, since 2011
• Acoustical Society of America, Fellow, since October 2009