| Atherosclerosis is a common cause of death in most Western societies. The disease is characterized by the formation of fatty, fibrous, and/or calcified plaques, within the arterial wall, which alter the mechanical properties of the arterial wall. The formation of these plaques often leads to clinical complications, such as thromboses, stenoses, due to changes in the hemodynamic properties. Imaging techniques can be used to study the arterial wall; however, the resolution of clinical imaging systems is generally not sufficient to observe small changes in the arterial wall properties. As a result, this thesis focuses on the development of two novel in vitro radiographic techniques (dual-energy radiography and the saline/iodine displacement technique) which can be used in basic atherosclerosis research to measure the thickness of the bone- and soft-tissue-equivalent components of the arterial wall.;Both dual-energy radiography and the saline/iodine displacement technique are radiographic techniques which produce high-resolution two-dimensional maps of bone- and soft-tissue-equivalent components of arterial specimens. Both techniques consist of obtaining two basis images of a specimen (at two different x-ray energies), followed by a non-linear decomposition of the basis images into two basis-material components, namely the bone-and soft-tissue-equivalent components.;The accuracy and precision of both techniques are reported in an attempt to characterize their ability at measuring tissue composition. Bone-equivalent thickness measurements obtained with dual-energy radiography were very accurate (25 $mu$m) and precise (75 $mu$m), whereas soft-tissue-equivalent thickness measurements were very inaccurate (750 $mu$m) and quite imprecise (220 $mu$m). Bone-equivalent thickness measurements obtained with the saline/iodine displacement technique were very accurate (110 $mu$m) and precise (60 $mu$m), and soft-tissue-equivalent thickness measurements were also very accurate (110 $mu$m) and precise (90 $mu$m).;The very high accuracy and precision of the bone-equivalent thickness measurements obtained with dual-energy radiography, as well as the high accuracy and precision of the soft-tissue-equivalent thickness measurements obtained with the saline/iodine displacement technique make these two radiographic techniques promising complementary techniques for analyzing the size and location of calcified atherosclerotic plaques in excised arterial specimens. |
