US5694934A
Expired / Lapsed
US
⏱️ 0.0 years remaining
MR studies in which a paramagnetic gas is administered to a living patient
Assignee: Beth Israel Deaconess Medical Center
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Filing: 1996-04-17
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Granted: 1997-12-09
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Expires: 2016-04-17
Abstract
Abstract A paramagnetic gas such as oxygen is administered twice at different concentrations to a living patient, as by causing the patient to breathe air and causing the patient to breathe pure oxygen. Two T1-weighted MR images are then acquired of a region in which the gas is present; advantageously, the region includes the patient's lungs. Because the paramagnetic gas shortens the T1 relaxation time of e.g. the patient's lung tissue, a comparison of the T1-weighted MR images shows where the gas has reached the patient's lung tissue and where the gas has been prevented from reaching the patient's lung tissue. This permits the radiologist to carry out e.g. a ventilation study without administering a radioactive material to the patient.
Inventors
- 👤 Robert R. Edelman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 00:24
CPC Classifications
G; G01; G01R; G01R33/00; G01R33/20; G01R33/44; G01R33/48; G01R33/54; G01R33/56; G01R33/5601; G01R33/50
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
67 words
A method of obtaining MR images for use in conducting a ventilation study, comprising the following steps performed in order: causing the patient to breathe a paramagnetic gas at a predetermined concentration; acquiring a T1-weighted MR image of said at least one lung; causing the patient to breathe the paramagnetic gas at a different concentration; and acquiring another T1-weighted MR image of said at least one lung.
Claim 2
Independent Claim
67 words
A method of obtaining MR images for use in conducting a ventilation study, comprising the following steps performed in order: causing the patient to breathe a paramagnetic gas at a predetermined concentration; acquiring a T1-weighted MR image of said at least one lung; causing the patient to breathe the paramagnetic gas at a different concentration; and acquiring another T1-weighted MR image of said at least one lung.
Claim 3
Dependent Claim
11 words
The method of claim 1, wherein the gas is pure oxygen.
Claim 4
Dependent Claim
17 words
The method of claim 1, wherein said acquiring steps are carried out using identical MR pulse sequences.
Claim 5
Dependent Claim
15 words
The method of claim 3, wherein the MR pulse sequence has a short echo time.
Claim 6
Dependent Claim
17 words
The method of claim 4, wherein the MR pulse sequence is of the turbo spin echo type.
Claim 7
Dependent Claim
23 words
The method of claim 3, wherein said MR pulse sequence is insensitive to magnetic field inhomogeneities existing within said at least one lung.
Claim 8
Independent Claim
68 words
A method of conducting an MR study of a region of a living patient, which region includes a body cavity, comprising the following steps performed in order: introducing a paramagnetic gas at a predetermined concentration into said body cavity; acquiring a T1-weighted MR image of said region; introducing the paramagnetic gas into the body cavity at a different concentration; and acquiring another T1-weighted MR image of said region.
Claim 9
Independent Claim
68 words
A method of conducting an MR study of a region of a living patient, which region includes a body cavity, comprising the following steps performed in order: introducing a paramagnetic gas at a predetermined concentration into said body cavity; acquiring a T1-weighted MR image of said region; introducing the paramagnetic gas into the body cavity at a different concentration; and acquiring another T1-weighted MR image of said region.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2000-12-08 | 2001-06-09 | 2001-12-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2004-12-08 | 2005-06-09 | 2005-12-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2008-12-08 | 2009-06-09 | 2009-12-09 | $7700.00 | Window Closed / Lapsed |