Current Medical Imaging - Volume 8, Issue 1, 2012

During the last decade, numerous methods and devices have been developed implementing elastography or mechanical imaging in various medical applications such as the differentiation of benign and malignant lesions in the liver, breast and prostate as well as the characterization of vaginal wall elasticity. Elastography is a noninvasive method in which stiffness or strain of soft tissue are used to detect or classify tumor Read More

From times immemorial, medical practitioners have used palpation for detection and characterization of pathologies. Recently, a new diagnostic imaging modality has emerged, called elasticity imaging (EI), which is an extension of the ancient art of palpation. Various imaging modalities may be used for EI, including ultrasound, MRI or even X-ray, to visualize the elasticity (stiffness) of soft tissue structures. Elasticity imaging is Read More

The methods used to estimate tissue elasticity based on the motion of local inhomogeneities such as laser-induced gas microbubbles, magnetic nanoparticles and other targets under an externally applied force are reviewed. The theoretical bases of the motion of a target in a viscoelastic medium are described. Given various targets differing in size, these methods allow for elasticity measurements at different levels of spa Read More

Palpation is an established screening procedure for the detection of several superficial cancers including breast, thyroid, prostate, and liver tumors through both self and clinical examinations. This is because solid masses typically have distinct stiffnesses compared to the surrounding normal tissue. In this paper, the application of Harmonic Motion Imaging (HMI) for tumor detection based on its stiffness as well as its relevance Read More

Measurement of tissue elasticity has emerged as an important advance in medical imaging and tissue characterization. However, soft tissue is inherently a viscoelastic material. One way to characterize the viscoelastic material properties of a material is to measure shear wave propagation velocities within the material at different frequencies and use the dispersion of the velocities, or variation with frequency, to solve for th Read More

The rupture of atherosclerotic plaques is considered to be the main cause of cardiovascular events like stroke and myocardial infarction. Early detection of atherosclerotic plaques that have a high risk to rupture is desired to be able to intervene before the cardiovascular event occurs. During the cardiac cycle the vessel wall and plaque are deformed by the pulsating blood. The resulting strains can be estimated locally b Read More

Often compared to the practice of manual palpation, magnetic resonance elastography is an emerging technology for quantitatively assessing the mechanical properties of tissue as a basis for characterizing disease. The potential of MRE as a diagnostic tool is rooted in the fact that normal and diseased tissues often differ significantly in terms of their intrinsic mechanical properties. MRE uses magnetic resonance imaging (MRI) i Read More

Elasticity imaging is a rather recent non-invasive imaging modality which provides in-vivo data about the viscoelastic properties of tissue. With manual palpation being an integral part of many diagnostic procedures, it is obvious that elasticity imaging has many interesting and promising potentials in medical imaging, i.e. from tissue/lesion characterization over therapy follow-up to guidance during interventions which invol Read More

Mechanical Imaging (MI) is a branch of Elastography. MI differs from conventional ultrasonic and MR elastography in that it evaluates soft tissue mechanical structure using stress data rather than dynamic or static strain data. MI closely mimics manual palpation because the MI probe with a force sensor array attached to its tip acts as a palpating finger. MI is intrinsically a three-dimensional imaging modality because the surf Read More