Abstract: In a nuclear magnetic resonance (NMR) diagnostic apparatus, the NMR signals from a portion of an object excited repeatedly by the same type excitation pulses are temporarily stored and the signal-to-noise (S/N) ratio thereof is improved by summing together at least two cos signal components, or two sin signal components of the NMR signals which were taken during these examination periods. An image processing circuit is used to process the NMR signals with impioned S/N ratio so as to obtain a tomographic image of the object.

Abstract: An NMR diagnostic apparatus and method for producing a high spatial resolution image of a thick, predetermined region of an object under NMR examination. A static magnetic field is applied to the object along its longitudinal axis. A G.sub.z magnetic field gradient is applied to the object along the longitudinal axis for a first time period. This causes magnetizations of individual nuclear spins within the object to rotate at different phases depending upon the position of the nuclei within the predetermined region of the object. Radio frequency pulses are then applied along the longitudinal axis of the object, in the absence of any magnetic field gradient. The RF pulses excite the nuclei within the predetermined region. During a second time period, a magnetic field gradient G.sub.xy is applied to the object in a direction transverse to the longitudinal axis.

Abstract: Reception signal processing apparatus in nuclear magnetic resonance diagnostic apparatus to display as an image the distribution of the spin density or relaxation time of specified atomic nuclei existing in an object utilizing nuclear magnetic resonance phenomena including a phase demodulator for phase demodulating a nuclear magnetic resonance signal evoked by nuclear magnetic resonance phenomena in accordance with two reference waves whose phases are different from one another by 90.degree., an analog-to-digital converter for digitalizing the separated two signals obtained by the phase demodulator, and a phase correction processor for automatically correcting the phase difference between the reference waves and nuclear magnetic resonance signal to produce a frequency spectrum by processing the digitalized signals.

Abstract: An emission type computed tomography apparatus comprises a mechanism for rotating a detector along a circle centered at a human body to whom radioisotope is previously given, and a circuit for reconstructing a tomogram in accordance with an output signal from said detector. The rotating mechanism further has a member for slanting the detector with respect to a tangential line of the circle, a member for slanting said detector with respect to the body axis, and a member for changing the radius of the rotating circle of the detector.