Minimum basis set MR angiography
US5034694A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 22, 1989 |
| Grant date | Jul 23, 1991 |
| Priority date | — |
| Expiry date | Nov 22, 2009 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R33/563
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A radio frequency pulse (32), a gradient pulse (34), and a first frequency offset pulse (38a) are applied to cause the presaturation region (36a) adjacent one face of an imaging volume (30) such that material flowing into the imaging volume from that face is saturated. An imaging sequence is applied which generates magnetic resonance image data that has non-saturated flow in the imaging volume identified by a characteristic phase modulated intensity. The saturation and gradient pulses are applied again with a second frequency offset pulse (38b) to position the saturation region (36b) adjacent the opposite face of the image volume. The exact same imaging sequence is applied to generate a second set of image data in which non-saturated flowing material is identified by a characteristic phase modulated intensity. Magnitude values from these two data sets are reconstructed (72, 74) into image representations that are subtractively combined (76), to form a difference image representation. In the difference image representation, the static material has essentially a zero value, flowing material that entered from one face is strictly positive, and flowing material that entered from the ot…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.