The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
Design of RF pulses for parallel excitation using phased array transmit coils in MRI requires the B1+ maps that are estimated from B1+ mapping experiments. This paper characterizes the effects of B1+ mapping errors on the resulting excitation pattern using a small perturbation analysis based on linearization of the Bloch equation. The accuracy of the proposed perturbation analysis is validated...
Compressed Sensing (CS), as a new framework for data acquisition and signal recovery, has been applied to accelerate conventional magnetic resonance imaging (MRI) with Fourier encoding. However, Fourier encoding is not universal and weakly spreads out the energy of most natural images. This limits the achievable reduction factors. In this paper, we propose a Toeplitz random encoding method that is...
Large-tip-angle multidimensional radio-frequency (RF) pulse design is a difficult problem, due to the nonlinear response of magnetization to applied RF at large tip-angles. In parallel excitation, multidimensional RF pulse design is further complicated by the possibility for transmit field patterns to change between subjects, requiring pulses to be designed rapidly while a subject lies in the scanner...
A combined optimization method is proposed to deal with the practical engineering problems of optimization design. In this method, orthogonal design is used to ascertain the importance of design variables and the adjustment direction of each factor; response surface model is applied to reducing the computational effort; and genetic algorithm is adopted as a searching tool for the optimization of object...
Dynamic contrast-enhanced (DCE) MR cardiac imaging has been recognized as a unique and powerful tool for assessing both cardiac functions and physiological conditions of the heart tissues (e.g., tissue rejection following heart transplantation). However, because of cardiac motion and the limited data acquisition speed of existing MRI techniques, it has been very difficult to acquire dynamic images...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.