MR studies in which a paramagnetic gas is administered to a living patient

• US 5,694,934 A
• Filed: 04/17/1996
• Issued: 12/09/1997
• Est. Priority Date: 04/17/1996
• Status: Expired due to Term

• Current Assignee: Beth Israel Hospital
• Original Assignee: Beth Israel Hospital
• Inventors: Edelman, Robert R.
• Primary Examiner(s): Lateef, Marvin M.
• Assistant Examiner(s): MANTIS MERCADER, ELENI M
• Application Number:
  US08/633,982
• Time in Patent Office: 601 Days
• Field of Search: 128/653.1, 128/653.2, 128/653.4, 128/654, 128/716, 324/307, 324/309, 424/9.3, 424/9.4, 424/9.1
• US Class Current: 600/410
• CPC Class Codes: G01R 33/50 based on the determination of relaxation times , e.g. T1 measurement by IR sequences; T2 measurement by multiple-echo sequences
• CPC Class Codes: G01R 33/5601 involving use of a contrast agent for contrast manipulation, e.g. a paramagnetic, super-paramagnetic, ferromagnetic or hyperpolarised contrast agent

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.

Claims

1. 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.

2. The method of claim 1, wherein the gas is pure oxygen.

3. The method of claim 1, wherein said acquiring steps are carried out using identical MR pulse sequences.

4. The method of claim 3, wherein the MR pulse sequence has a short echo time.

5. The method of claim 4, wherein the MR pulse sequence is of the turbo spin echo type.

6. The method of claim 3, wherein said MR pulse sequence is insensitive to magnetic field inhomogeneities existing within said at least one lung.

7. 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.