II New Patents

thermography, by one-, two-, or three- dimensional reconstruction techniques from chemical shift, relaxation times, (e.g., Tl or T2,) spin-spin couplings and quadrupole couplings for an element of a compound having at least one conformational isomer in an object or animal in- fluenced by a temperature in the object or animal. The methods disclosed are applicable to inanimate and animate solids.

boiled off from the cryostat interior. The cryostat which incorporates the present inven- tion is particularly useful in housing NMR medical diagnostic imaging magnet and coil sys- tems.

4563647

NUCLEAR MAGNETIC 4558425 RESONANCE METHODS AND

APPARATUS NMR IMAGING APPARATUS OF

CHANGEABLE INSPECTING ZONE SIZE

Ian R Young, Sunbury on Thames, United Kingdom assigned to Picker International L,imited

Etsuji Yamamoto, Kensuke Sekihara, Hideki Kohno, Shinji Yamamoto, Hachioji, Japan as- signed to Hitachi Ltd

In an imaging apparatus using nuclear magnetic resonance which includes apparatus for gene- rating a static magnetic field, a linear gradient magnetic field and a radio frequency magnetic field, respectively, signal detection device for detecting the nuclear magnetic resonant signal from an object to be inspected, a computer for calculating from the detection signal an image and output device for displaying the result of cal- culation by the computer, the improvement wherein the size of the object to be inspected is detected by use of ultrasonic wave or light beams and a signal indicative of the detected size of the object is applied to the linear gradient magnetic field generation apparatus so as to control the in- tensity of the linear gradient magnetic field.

A method of exciting nuclear magnetic resonance at a particular location of a body com- prises: exciting first nuclear spins in the body (A, Gx, -G’x, B, Gxd, C, Gy, -G’y, D) so that spins occurring in a first selected region of the body have their spin vectors lying in a first direction and any spins occurring elsewhere in the body have their spin vectors lying in a plane normal to the first direction; dephasing the spins in the body whose vectors lie in said plane (Gyd); and exciting nuclear spins in a second selected region of the body (E, Gz, -G’z) which intersects said first region at said particular location so that the vectors of the resultant spins in said particular location only are aligned in said plane. The method finds particular application in providing data for chemical analysis of material at a par- ticular location of a body. Apparatus for car- rying out the method is also described.

4562703 4564017

PLUG TUBE FOR NMR MAGNET METHOD AND APPARATUS FOR CRYOSTAT RESPIRATION MONITORING

WITH AN NMR SCANNER Russell Miller, Thomas E Price assigned to General Electric Company Gary Glover assigned to General Electric Com-

pany A vent tube which is particularly useful for horizontal cryostat penetration comprises a plurality of conduit sections joined by mating rings which facilitate the incorporation of rela- tively deep circumferential grooves in the con- duit sections. Thermal contact springs, preferably in the form of a single strip are dis- posed in these circumferential grooves so as to provide a means for transfer of thermal energy from the cryostat interior to the exterior either for general refrigeration requirements or for li- quefaction of coolant vapor which may have

A method for eliminating or reducing breathing artifacts due to motion-induced phase and am- plitude errors in the phase-encoding dimension when using Fourier transform imaging methods, such as spin warp, utilizes a repetition time (TR) which is an odd multiple of one quarter of the breathing cycle. In the preferred embodiment, method and apparatus are provided for deter- mining the breathing cycle by monitoring the in- tegrated spin-echo signal magnitude spectrum as a function of time.