New Patents III

4730620

NUCLEAR MAGNETIC RESONANCE METHOD AND

APPARATUS FOR REDUCING MOTION ARTIFACTS

David R Bailes, London, United Kingdom as- signed to Picker International Ltd

A method, and an apparatus for performing the method, are described, for imaging a region of a body using NMR in which part of the region is moving with a motion such that its displacement with respect to time is a nonmonotonic function during the time period over which NMR data signals are collected. The data signals are collec- ted in an order dependent on the motion such that motion artifacts are reduced.

An improvement in NMR imaging techniques is disclosed, whereby the image is shadowed to in- tensify and contrast the image generated by the NMR sensitive nuclei, as a consequence of the introduction to the examined locus, e.g., human tissue of ferromagnetic, diamagnetic or para- magnetic particles. The intensified and clarified image is itself diagnostically valuable, in ac- cordance with art recognized methods but also provides an improved information base for establishing and controlling treatment modes, especially in determining spatial density and distribution of particles by comparing standard and enhanced images. According to a preferred embodiment, metabolizable particles are em- ployed, whereby the change and rate of change with metabolic time can be imaged, compared, and correlated with various metabolic diseases or malignant states.

4730621 4731583

BLOOD PRESSURE MEASUREMENT

Frank D Stott, Oxford, United Kingdom as- signed to National Research Development Cor- poration

METHOD FOR REDUCTION OF MR IMAGE ARTIFACTS DUE TO

FLOWING NUCLEI BY GRADIENT MOMENT NULLING

Gary H Glover, Matthew O’Donnell assigned to General Electric Company

Blood pressure measurement apparatus com- prises means for variably occluding a body zone by progressive application of external pressure between levels respectively above systolic and below diastolic, means for detecting variations in blood volume in said zone during variable occlu- sion thereof, and means responsive to the oc- cluding and detecting means to indicate as systolic and diastolic pressures the values of said external pressure respectively when the maxi- mum and minimum detected volume levels are each about half way between zero and the maxi- mum level following the last minimum which does not depart significantly from zero. The blood volume variations are preferably deter- mined by reference to light transmission through the zone, suitably infrared, but other measures are suitable as determined by strain gauge, pro- ton magnetic resonance or microwave absorbtion.

A technique has been developed which reduces blood-flow artifacts in multi-echo, multi-slice magnetic resonance (MR) imaging by rephasing spins which have arbitrary velocity as well as static spins. The technique requires tailoring of the gradient structure along at least one of the three axes so as to null out in the preferred em- bodiment the zeroth and first moments of the gradient distributions.

4731584

MAGNETIC RESONANCE PROBE FOR OPERATION AT

FREQUENCIES ABOVE SELF RESONANCE

John L Patrick assigned to Picker International Inc

4731239

METHOD FOR ENHANCING NMR IMAGING; AND DIAGNOSTIC

USE

Robert Gordon

A magnetic field control (A) causes a magnetic field through an imaging region of a magnetic resonance spectrometer. A radio frequency generator (20) generatesradio frequency signals which are transmitted on a transmission line (22) to a probe coil (C). Magnetic resonance signals received by the probe coil (C) are conveyed over