Apparatus and methods for magnetic resonance (MR) angiography using hydrogen polarized at low temperatures
US5611340A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 2, 1995 |
| Grant date | Mar 18, 1997 |
| Priority date | — |
| Expiry date | Oct 2, 2015 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61B5/055
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
A magnetic resonance (MR) active invasive device system employs a small, high-field polarizing magnet, and a large low-field magnetic resonance (MR) imaging magnet for the purpose of generating MR angiograms of selected blood vessels. A subject is positioned in a large low-field MR imaging magnet. A catheter is inserted into the patient at or near the root of a vessel tree desired to be imaged. A hydrogen gas is first cooled and condensed into a liquid state, and then passed through the small high-field polarizing magnet where it becomes highly polarized. A contrast fluid is then made by chemically combining the polarized hydrogen with oxygen to obtain highly polarized water. The water is then heated to physiologic temperatures and, if desired, made more physiologically compatible with the addition of substances such as salts. The physiologically conditioned polarized fluid is then introduced into the subject through the catheter. Radiofrequency (RF) pulses and magnetic field gradients are then applied to the patient as in conventional MR imaging. Since the fluid has a larger longitudinal magnetization than tissue which has not passed through the polarizing magnet, the fluid produc…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.