Viscoelastic properties of liver measured by oscillatory rheometry and multifrequency magnetic resonance elastography.
نویسندگان
چکیده
The mechanical properties of liver can sensitively indicate the progression of hepatic fibrosis. Mechanical tissue characterization involves the analysis of the complex shear modulus measured either by oscillatory rheometry or by in vivo elastography. In this study, bovine liver specimens were investigated by oscillatory rheometry and multifrequency magnetic resonance elastography (MRE) in a common frequency range between 25.0 and 62.5 Hz. The results were compared with in vivo MRE of human liver. Storage and loss moduli were quantified, and the data were also analyzed employing a springpot model, yielding a stiffness-related parameter of 2.96+/-0.53 kPa in bovine liver by rheometry and of 2.20+/-0.45 kPa in human liver by in vivo MRE. Furthermore, MRE of excised bovine liver showed that stiffness tended to increase with decreasing sample temperature. In conclusion, mechanical tissue characterization by multifrequency MRE agrees well with oscillatory rheometry, which validates MRE as a method for investigating the rheology of liver tissue.
منابع مشابه
In vivo MR elastography of liver: Comparison to oscillatory rheometer studies of tissue specimen
Introduction: Magnetic Resonance Elastography (MRE) is capable to measure the mechanical properties of living tissue by externally introduced shear vibrations and phase contrast MRI [1]. In multifrequency MRE the complex shear modulus G*(ω) of biological tissue is measured at various mechanical vibration frequencies simultaneously. Viscoelastic tissue parameters can then be calculated by fittin...
متن کاملIn vivo wideband multifrequency MR elastography of the human brain and liver.
PURPOSE To demonstrate the feasibility of in vivo wideband MR elastography (wMRE) using continuous, time-harmonic shear vibrations in the frequency range of 10-50 Hz. THEORY AND METHODS The method was tested in a gel phantom with marked mechanical loss. The brains and livers of eight volunteers were scanned by wMRE using multislice, single-shot MRE with optimized fractional encoding and synch...
متن کاملAssessment of liver viscoelasticity using multifrequency MR elastography.
MR elastography (MRE) allows the noninvasive assessment of the viscoelastic properties of human organs based on the organ response to oscillatory shear stress. Shear waves of a given frequency are mechanically introduced and the propagation is imaged by applying motion-sensitive gradients. An experiment was set up that introduces multifrequency shear waves combined with broadband motion sensiti...
متن کاملBrain Viscoelasticity Measured by Magnetic Resonance Elastography
The knowledge of brain tissue mechanical properties is a critical issue in the head injury biomechanics research field. Due to experimental limitations, brain tissue has been characterized in vitro, whereas its actual in vivo behavior remains poorly known. We propose the use of Magnetic Resonance Elastography as a non invasive, non destructive tool for measuring the viscoelastic properties of b...
متن کاملHigh-resolution mechanical imaging of the human brain by three-dimensional multifrequency magnetic resonance elastography at 7T
Magnetic resonance elastography (MRE) is capable of measuring the viscoelastic properties of brain tissue in vivo. However, MRE is still limited in providing high-resolution maps of mechanical constants. We therefore introduce 3D multifrequency MRE (3DMMRE) at 7T magnetic field strength combined with enhanced multifrequency dual elasto-visco (MDEV) inversion in order to achieve high-resolution ...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Biorheology
دوره 47 2 شماره
صفحات -
تاریخ انتشار 2010