Main description:

Magnetic resonance elastography (MRE) is an imaging technology, combining magnetic resonance imaging (MRI) with mapping of the visco-elastic properties of tissues. Its main clinical application is the detection of neoplasm. This reference gives a sound introduction to the theoretical background, covering both principles of magnetic resonanace imaging and (tissue) mechanics. A special emphasis is put on technical solutions: scanners and motion gereantion hardware, image acquisition, postprocessing, and parameter reconstrction are discussed in detail. After discussion of the biomechganical properties of all relevant tissue types, promiment and timely examples of clinical and preclinical applications are given. A chapter on alternative and complimentary approaches such as elastography by ultrasound completes the book.

Contents:

Preface by the authors Foreword by Richard L. Ehman THEORETICAL BACKGROUND Magnetic Resonance Imaging: Nuclear magnetic resonance Magnetic resonance imaging fundamentals Fast imaging techniques MR Elastography principles Mechanics: Viscoelasticity Theory Strain Stress Hooke's law Symmetries Engineering constants Viscoelastic models Waves in viscoelastic media Waves in anisotropic elastic media Energy density and energy flux Wave scattering Poroelasticity TECHNICAL SOLUTIONS Hardware: Scanner systems Clinical scanners Ultrahigh field and animal MRI Permanent magnetic field MRI Motion Generation: Lorentz coils Distant drivers Loudspeakers Piezo stacks Air pressure Wave Enery Transfer: Rigid Pneumatic Hydraulic Image Acquisition: Requirements GRE SPE bSSFP SE-EPI Tradeoffs, compromises, and pitfalls Postprocessing: Unwrapping Filters Parameter Reconstruction: Forward problem Analytical solutions Finite differences Finite elements Inverse problem Local Frequency Estimation (LFE) Phase Gradient Methods Finite differences Algebraic Helmholtz Inversion: - planar case - 3D - dual inversion Finite Elements: - overlapping subzones - travelling wave expansion - nonlinear inversion Relative wave amplitude methods BIOMECHANICS OF SOFT TISSUES Brain Lung Muscle Liver Spleen Kidney Uterus Nucleus Pulposus PRECLINICAL AND CLINICAL APPLICATIONS NAFLD, NASH, and Liver Fibrosis Portal Hypertension Brain diseases Diastolic dysfunction Muscular dysfunction Tumors ALTERNATIVE APPROACHES Intrisic activated MRE Liver Brain Compression sensitive MRE Time harmonic elastography by ultrasound