Abstract: An insertable coil (40) is inserted in a bore (12) of a magnetic resonance imaging apparatus. Primary field magnets (10) create a temporally constant magnetic field longitudinally through the insertable coil. A computer control (58) controls a radio frequency coil (46) and a gradient coil (42) to create magnetic resonance imaging sequences and process received magnetic resonance signals into image representations. The insertable gradient coil includes a cylindrical, dielectric former (44) of appropriate diameter to receive a patient's head. A pair of parabolic cutouts (62) are defined adjacent a patient receiving end of the dielectric former and are of an appropriate size to receive the patient's shoulders. In this manner, the patient's head can be centered in a longer head coil. Four thumbprint type x-gradient coil windings (72) are mounted symmetrically on the dielectric former with the parabolic cutouts (74) centrally on one side of the thumbprint coil windings.

Abstract: An examination region (12) is defined along a z-axis offset from a geometric center (30) of a gradient coil assembly (20). Cylinders of a non-conductive, non-magnetic material support x, y, and z-gradient coils (24, 26, 22) for causing orthogonal magnetic field gradients through the offset examination region. The z-gradient coil (FIG. 2 ) includes a plurality of distributed loop arrays with a winding pattern selected to cause a region of linear magnetic field gradients in the z-direction in a region offset toward a cylinder first end (32). The x and y-gradient coils each include two pairs of oppositely disposed windings (FIG. 3 ) which include a pair of inner spirals (96, 98) offset towards the first end of the cylinder and an outer spiral (90) extending therearound. The outer spiral bows in (92) toward the cylinder first end and fans out (94) toward the second end.

Abstract: An examination region (12) is defined by an elliptically crossed-section cylinder (20) of a non-conductive, non-magnetic material. The x, y, and z-gradient coils (24, 26, 22) are mounted on elliptically crossed-section cylindrical surfaces along the former for causing gradient magnetic fields within the examination region. Each of the x, y, and z-gradient coils includes a plurality of arrays or groups of coil loops. The arrays of coil loops are symmetric about a central plane of symmetry. To either side of the plane of symmetry, each of the first of the x, y, and z coil arrays (74, 80, 90) include at least a first group of loops in which current flows in a clockwise direction and a second array of loops (76, 82, 90) in which current flows in an opposite direction.