Jozef (Jeff) Duyn (NINDS)
This invention is a new three-dimensional magnetic resonance imaging device that will allow better imaging of biologic tissue. Conventional BURST technology excites a set of equally spaced, narrow strips in an object and creates an image from a single slice, perpendicular to the direction of the strips. In order to scan multiple slices or for three-dimensional imaging, repeated excitation of the same strips is required. For ultra-fast scanning, repetition times are short compared to longitudinal relaxation times, leading to saturation effects and, thus, inefficiency. In addition, when scanning in two-dimensional mode, the commonly used slice selective RF refocusing pulse also leads to additional saturation. This new device utilizes BURST RF excitation pulses and shifts the excitation region after successive excitation repetitions, thus, minimizing saturation and increasing efficiency while improving the signal to noise ratio. This instrument allows three-dimensional data sets on a human brain scan to be collected within a few seconds using a standard clinical scanner.