Samuel A. Wickline, MD
Professor of Medicine

Office location: 4412 Kingshighway Bldg.
Telephone: 314/454-8635
fax: 314/454-5265
e-mail address: saw@howdy.wustl.edu

Research interests
We conduct basic ultrasonic research with implications for molecular mechanisms of tissue remodeling and their effects on tissue material properties. Ultrasonic characterization of cardiac and vascular tissues based on quantitative analysis of backscatter permits detection of pathologic changes in heart muscle and vascular structure in experimental animals and human subjects. The hypothesis underlying this research is that pathologic changes in cardiac and vascular tissues produce alterations in the fundamental physical properties of tissues, such as elasticity, density, and three-dimensional organization that can be quantified by measuring ultrasonic backscatter and attenuation over a range of frequencies. Quantifiable ultrasonic parameters such as backscatter, attenuation, and frequency dependence of scattering define complementary intrinsic scattering properties that facilitate characterization of cardiovascular pathology.

One area of interest is delineation of cellular mechanisms of cardiac remodeling in conditions such as hypertension, cardiomyopathy, and infarction. Acoustic methods for characterizing this remodeling process, which involves rearrangement of fiber architecture and composition, are unique in that they permit direct determination of tissue physical properties without having to destroy the tissue in the process. These principles also apply to characterization of vascular structures to quantify lesion composition and their propensity for rupture and occlusion.

Another area of interest is contrast agents. We have recently invented a bifunctional ultrasound and MRI lipid-coated particulate contrast agent based on an emulsion technology that permits specific targeting of molecular ligands. Cardiovascular uses may include sensitive detection of vascular and cardiac thrombi and active myocarditis. Its use for detection of certain solid tumors such as colon, liver, breast, and prostate promises to enhance our ability to diagnose, treat, and follow these lesions.

Recent publications
Hall CS, Scott MJ, Lanza GM, Miller JG, Wickline SA: The extracellular matrix is an important source of ultrasound backscatter from myocardium. J Acoust Soc Am 2000;107:612-619.

Hall CS, Lanza GM, Rose JH, Kaufmann RJ, Fuhrhop RW, Handley SH, Waters KR, Miller JG, Wickline SA: Experimental determination of phase velocity of perfluorocarbons: applications to targeted contrast agents. IEEE Ultrasound Ferroelec Freq Contr 2000;47:75-84.

Lanza GM, Abendschein DR, Hall CS, Marsh JN, Scott MJ, Scherrer DE, Wickline SA: Molecular imaging of stretch induced tissue factor expression in carotid arteries with intravascular ultrasound. Invest Radiol 2000;35:227-234.

Lanza GM, Trousil RL, Wallace KD, Rose JH, Hall CS, Scott MJ, Miller JG, Eisenberg PR, Gaffney PJ, Wickline SA: In vitro characterization of a novel, tissue-targeted ultrasonic contrast system with acoustic microscopy. J Acoust Soc Am 1998;104:3665-3672.

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