Abstract: An MRI breast coil is provided with a large transverse access portal and a stereotactic frame for guiding a biopsy needle. The portal is covered by thin sheath of plastic to retain the breast but still allow insertion of the needle to any location. The frame aligns the needle by azimuth, height and depth.

Abstract: The present invention provides an RF receiver coil with improved signal-to-noise ratio (SNR) characteristics, designed to be positionable immediately adjacent to or surrounding the anatomical region of the body of the patient which is desired to be imaged. The surface coil of the invention is designed for use as a signal receiver, for high resolution unilateral imaging of a localized region, with improved penetration depth. The RF surface coil minimizes capacitive coupling to the patient's body, and in conjunction therewith reduces resistive coupling of the coil to the body of the patient. The RF receiver coil of the invention includes at least two turns of an electrical conductor formed in a solenoidal configuration, with the at least two turns being positioned in spaced apart relationship defining an interturn spacing therebetween. Each of the turns of the coil includes a predetermined number of capacitive splits spaced at intervals along the length of the conductor forming the turns.

Abstract: A coil is used to transmit r.f. energy pulses through an object to be imaged. The pulses are transmitted at a plurality of directions coplanar with the image plane. A receiving coil picks up the transmitted r.f. energy. The received energy is converted to values corresponding to the amount of absorption of the energy by the object at a particular direction. By using r.f. frequencies having a wavelength less than the greatest dimension of the object, reflection, refraction and diffraction effects are minimized. The use of coils for transmitting and receiving allows propagating the energy with reasonable sized devices. Because tomographic techniques are used for image creation, the large wavelength does not seriously impact resolution.

Abstract: A technique for producing multiple spin echo signals following an initial excitation pulse is provided. A first inverting pulse is applied a given time interval following the initial excitation pulse, resulting in the formation of the usual first spin echo signal after passage of the given time interval. At a later point in time, a second inverting pulse is applied. The time interval between the initial excitation pulse and this second inverting pulse is not required to be harmonically related to the first given time interval. This results in the production of at least a second, later occurring spin echo signal which does not contain harmonically-related artifact components of the earlier pulses and spin echo signals.