Abstract: A magnetic resonance imaging apparatus has a gantry including various coils such as a static field coil and gradient field coils, a top board for supporting an examinee and moving the examinee into and out of an opening of the gantry, and an approximately cylindrical RF coil defining a hollow space therein. The RF coil is set to the top board, with an axis of the hollow space extending at an angle to the horizontal. The examinee's imaging site is inserted into the hollow space of the RF coil to have sectional images picked up. Since the RF coil is set to the top board with the axis of the hollow space inclined relative to the horizontal, sectional images may be picked up by using the approximately cylindrical RF coil while allowing the examinee to take a comfortable posture without enlarging the RF coil.

Abstract: An orthogonal RF (radio frequency) coil for use in an MRI (Magnetic Resonance Imaging) apparatus includes two resonator coil loops arranged to have sensitivity directions orthogonal to each other, each of the resonator coil loops having two power supply points; and power supply circuits for supplying power so as to provide a 90.degree. RF phase difference between the two power supply points of one of the resonator coil loops and the two power supply points of the other resonator coil loop, and a 180.degree. RF phase difference between the two power supply points of each of the resonator coil loops at a frequency establishing a differential mode. The RF phase difference between the two power supply points of each resonator coil loop is forcibly inverted at the frequency establishing the differential mode. This cancels in-phase resonance currents of the differential mode, to enhance the orthogonality of RF magnetic fields.

Abstract: A gantry defines an opening, and a surface coil is mounted in a predetermined position inside the opening. In tomography using this MRI apparatus, an examinee supported on a top board is moved into the opening. At this time, the top board is movable without being obstructed by the surface coil. The surface coil receives NMR signals from a photographed site lying directly over the surface coil. Sectional images are prepared based on the NMR signals received. When shifting the site to be photographed, the operator in a scanner control room gives an instruction to move the top board, thereby adjusting a photographing position. It is unnecessary for the examinee to move on the top board, or for the operator to move from the scanner control room to the photographing room. The examinee entering the gantry opening is illuminated by light from a light projector. A position of the top board when the light illuminates the site to be photographed is regarded as a starting point.