Magnetic resonance elastography: A review

Abstract

Magnetic Resonance Elastography (MRE) is a rapidly developing technology for quantitatively assessing the mechanical properties of tissue. The technology can be considered to be an imaging-based counterpart to palpation, commonly used by physicians to diagnose and characterize diseases. The success of palpation as a diagnostic method is based on the fact that the mechanical properties of tissues are often dramatically affected by the presence of disease processes such as cancer, inflammation, and fibrosis. MRE obtains information about the stiffness of tissue by assessing the propagation of mechanical waves through the tissue with a special magnetic resonance imaging (MRI) technique. The technique essentially involves three steps: generating shear waves in the tissue,acquiring MR images depicting the propagation of the induced shear waves andprocessing the images of the shear waves to generate quantitative maps of tissue stiffness, called elastograms. MRE is already being used clinically for the assessment of patients with chronic liver diseases and is emerging as a safe, reliable and noninvasive alternative to liver biopsy for staging hepatic fibrosis. MRE is also being investigated for application to pathologies of other organs including the brain, breast, blood vessels, heart, kidneys, lungs and skeletal muscle. The purpose of this review article is to introduce this technology to clinical anatomists and to summarize some of the current clinical applications that are being pursued.

3D static elastography at the micrometer scale using Full Field OCT

“…Adding a map of mechanical properties as a supplementary contrast mechanism to morphological images could help diagnosis. During the last decade intensive research has been done to combine elastographic contrast with several biomedical imaging modalities with valuable results, particularly in MRI [2] or in ultrasonic imaging [3] where the elasticity information contributes to determining the final diagnosis. In the field of OCT imaging this mapping of mechanical properties was introduced by Schmitt [4] in 1998.…”

Excitation System for Magnetic Resonance Elastography Using Micro MRI

“…The samples (x, y, z = 50, 130, 40 mm, respectively) were prepared from a homogeneously structured 1.2 wt% agarose-water gel with a density of 1.0 g/cm 3 , which was kept at under 25 °C during the experiments. As in the previous measurement, G′ and G″ were measured in a general manner by using a torsional rheometer (RDAIII, Rheometric .…”

“…Elastic modulus and viscosity are determined quantitatively in the analysis of the generated wave patterns through viscoelastic tissue modeling. Actual measurements of the viscoelastic properties of human tissue have already been performed in vivo using clinical MRI systems and low-power excitation from an external vibrator (3) . Clinical MRE studies have been conducted to measure the hardness of several types of tissues including liver (4) , lung (5) , breast (6) (7) , brain (8) , muscle (9) , cartilage (10) , and trabecular bone (11) .…”

Convertible pneumatic actuator for magnetic resonance elastography of the brain

“…Most importantly, MRE can be used as a diagnostic tool, based on the contrast between mechanical properties of healthy and pathological tissue. MRE can be used to examine organs such as liver, breast, prostate, kidney, and new applications are still emerging [4]. The unique feature of MRE is that it can be used even for regions like the brain, where traditional manual palpation is not applicable [5] and [6].…”