Abstract: An improved motion-sensitization driven equilibrium (iMSDE) sequence based upon an MLEV-4 sequence is used for black-blood vessel wall imaging. The MSDE pulse pattern that is used us a preparation sequence for other procedures employed to acquire images has been modified to produce the iMSDE sequence by the addition of a second 180 degree refocusing pulse and two motion sensitization gradients. The iMSDE sequence thus includes a group of four radio frequency (RF) pulses, as well as additional magnetic gradient pulses that are not included in the conventional MSDE sequence. Computer simulations indicate that this new pulse sequence is substantially more immune to local B1 inhomogeneity than conventional sequences. In vivo experiments have demonstrated significant signal improvement at high first-order moments (m1) conditions compared to the traditional MSDE sequence.

Abstract: A two-point reconstruction technique provides an efficient clinical method for measuring parametric bound pool fraction and cross-relaxation rate constant spatial distributions in biological objects from two experimental measurements based on magnetization transfer effect obtained in magnetic resonance imaging (MRI). The method is based on linearization of an analytical pulsed magnetization transfer mathematical model so that spatial distribution maps of the bound pool fraction and cross-relaxation rate constant can be obtained in a time-efficient manner by using only two experimental magnetization transfer images of the bio-logical object in which water and macromolecules are present.

Abstract: An improved motion-sensitization driven equilibrium (iMSDE) sequence based upon an MLEV-4 sequence is used for black-blood vessel wall imaging. The MSDE pulse pattern that is used us a preparation sequence for other procedures employed to acquire images has been modified to produce the iMSDE sequence by the addition of a second 180 degree refocusing pulse and two motion sensitization gradients. The iMSDE sequence thus includes a group of four radio frequency (RF) pulses, as well as additional magnetic gradient pulses that are not included in the conventional MSDE sequence. Computer simulations indicate that this new pulse sequence is substantially more immune to local B1 inhomogeneity than conventional sequences. In vivo experiments have demonstrated significant signal improvement at high first-order moments (m1) conditions compared to the traditional MSDE sequence.

Abstract: A two-point reconstruction technique provides an efficient clinical method for measuring parametric bound pool fraction and cross-relaxation rate constant spatial distributions in biological objects from two experimental measurements based on magnetization transfer effect obtained in magnetic resonance imaging (MRI). The method is based on linearization of an analytical pulsed magnetization transfer mathematical model so that spatial distribution maps of the bound pool fraction and cross-relaxation rate constant can be obtained in a time-efficient manner by using only two experimental magnetization transfer images of the bio-logical object in which water and macromolecules are present.

Abstract: A reduced field-of-view (FOV) imaging technique combines suppression of signals from outer volume and inflowing blood. Both outer volume and blood suppression are achieved using an SFQIR (Small-FOV Quadruple-inversion-Recovery) preparative pulse sequence including two double-inversion pulse pairs separated by appropriate delays. Within each pair, inversion pulses are successively applied to the imaged slice and the slab orthogonal to the imaging plane, with the thickness equal to the FOV size in the phase-encoding direction. Each double-inversion results in a reinversion of the magnetization in a central part of the FOV, while outer areas of the FOV and inflowing blood remain inverted. The SFQIR module was implemented for single-slice and multislice acquisition with a fast spin-echo readout sequence. Timing parameters of the sequence corresponding to the maximal suppression efficiency can be found by niiziig variation of the normalized signal over the entire range of T1 occurring in tissues.