Selective Irradiation Line Scan Techniques for NMR Imaging

Selective irradiation is a technique used in Nuclear Magnetic Resonance Imaging to excite the nuclei in planar volumes. Using sequences of selective irradiations the signal received from a three dimensional object can be restricted to a line out of the object. This line can be moved through the object to produce tomographic images. A general description of the technique is presented. Two types of plane selection are analyzed. Example sequences using pairs of selected planes to select line volumes are considered. The imaging properties of a selective irradiation line scanner utilizing a Varian magnet with 30 cm diameter pole tips and a 10 cm gap, operated at 3.52 KGauss (15MHz hydrogen resonant frequency) are presented.