Abstract: An MRI method and an MRI system that simultaneously detect blood and/or CSF velocity or flow in plural slices or slabs preferably as not spatially adjacent. Two or more sets of interleaved slices or slabs can be assembled to cover the desired volume and derive higher quality MRI signals and images without a need for a contrast agent, even where the volume is too large for effective flow imaging with known techniques without contrast agent.
Abstract: An MRI scanner and an MRI method that effectively reduce the inherent difference in timing of TE in the SIR images by using alternating polarity of the slice selective gradient pulse Gs and corresponding alternate polarity in RF phase offset in the excitation pulse. By using alternating polarity selective gradients, the refocusing gradient pulse on the Gs axis can be eliminated between the excitation pulses so that the time spacing between the multiple SIR excitation pulses is reduced, and therefore the time delay between onset of slice signal decay is reduced. This results in an earlier possible TE of the first excited slice, hence less signal decay and higher SNR, and overall the TE of different slices can be more nearly the same.
Abstract: An MRI system and method for dynamic susceptibility contrast (DSC) imaging use multiplexed echo planar imaging (M-EPI) to essentially simultaneously acquire MR signals for perfusion parameter images of multiple slices. This essentially simultaneous acquisition of MR signals for multiple slices can be repeated in rapid succession without deteriorating T2* contrast, which makes it practical to image multiple perfusion phases and brings about other significant benefits.
Abstract: Quantitative assessment of haemodynamics by cycled arterial spin labeling (CACL) that distinguishes between blood magnetization tagged by a specific labeling pulse, using a time series acquisition in which all measured data sets are used for reconstruction of each single time step, thereby reducing measurement time while maintaining signal-to-noise ration compared to conventional ASL.
Abstract: Regional arterial spin labeling (regASL) speeds up acquisition without sacrificing the signal-to-noise ratio (SNR) of the resulting perfusion images by using the same control image (i.e. acquired without labeling of blood in a vessel) for two or more vascular territory measurements. This regional ASL is accomplished by creating prepared spin magnetization (e.g. inverted or saturated) in a specific blood vessel, instead of preparing spin magnetization in all feeding blood vessels. As in conventional ASL, two data sets are typically acquired in a downstream position: one with (label image) and one without preparation (control image) in one particular vessel.
Abstract: A method of detecting Parkinson's disease through MRI of substantial nigra pars compacta (SNc) tissue. The method involves obtaining a gray matter suppressed (GMS) MRI signal from the SNc tissue, obtaining a white matter suppressed (WMS) MRI signal of the SNc tissue, and combining information from the GMS and WMS MRI signals to produce resultant signals indicative of Parkinson's disease. A similar method can be used to detect Progressive Supranuclear Palsy. A method of distinguishing between the two diseases involves obtaining at least two starting MRI images of SNc tissue using different MRI parameters, and combining the starting images to compute resultant signals differentiating between the two forms of parkinsonism.
Abstract: MR imaging produces a projection image showing better image contrast between small blood vessels and background than traditional net intensity projection (NIP) images but more visual clues to vessel depth than traditional maximum intensity projection (MIP) images.
Type:
Grant
Filed:
May 22, 2002
Date of Patent:
March 28, 2006
Assignee:
Advanced MRI Technologies, LLC
Inventors:
Koichi Oshio, David A. Feinberg, Matthias Guenther
Abstract: MRI method and apparatus using simultaneous image refocusing of multiple MRI slices that have different phase histories imparted by applying different amount of additional energy to the different slices before the first refocusing, in combination with applying novel fid spoiling that suppresses interference between stimulated echoes and spin echoes of different slices while allowing non-interfering stimulated echoes to be added to the appropriate primary echoes.