Patent US4909785A successfully refreshed from Google Patents.
US6526307B2
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus to improve myocardial infarction detection with blood pool signal suppression
Assignee: GE Medical Systems Global Technology Co LLC
•
Filing: 2000-12-29
•
Granted: 2003-02-25
•
Expires: 2020-12-29
Abstract
Abstract A method and apparatus are disclosed for achieving suppression of blood pool signal to detect myocardial infarction using MR technology. After administering a contrast agent into the blood stream of a patient, an RF pulse sequence is applied that includes a slice-selective inversion pulse to suppress normal myocardial tissue followed by a notched inversion RF pulse designed to suppress blood pool in and around the region-of-interest. MR data is then acquired within the region-of-interest that not only has signals from normal myocardial tissue suppressed, but also has blood pool signal suppression to improve delineation of infarcted myocardium from the ventricular blood pool and normal myocardium.
Inventors
- 👤 Thomas K. F. Foo
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 13:58
CPC Classifications
G; G01; G01R; G01R33/00; G01R33/20; G01R33/44; G01R33/48; G01R33/54; G01R33/56; G01R33/5601; G01R33/563
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
76 words
A method of MR imaging with blood pool suppression comprising: administering a contrast agent into the blood stream of a patient; applying a pulse sequence having a slice-selective inversion RF pulse designed to suppress myocardial tissue followed by a notched inversion RF pulse designed to suppress blood pool at least within a region-of-interest; acquiring MR data in the region-of-interest; and reconstructing an MR image from the acquired MR data to assess a presence of myocardial infarction.
Claim 2
Independent Claim
76 words
A method of MR imaging with blood pool suppression comprising: administering a contrast agent into the blood stream of a patient; applying a pulse sequence having a slice-selective inversion RF pulse designed to suppress myocardial tissue followed by a notched inversion RF pulse designed to suppress blood pool at least within a region-of-interest; acquiring MR data in the region-of-interest; and reconstructing an MR image from the acquired MR data to assess a presence of myocardial infarction.
Claim 3
Dependent Claim
43 words
The method of claim 1 wherein the slice-selective inversion RF pulse has a section thickness of about 1 and 3 times that of a section thickness of an imaged slice and has an inversion time selected to null signal from normal myocardial tissue.
Claim 4
Dependent Claim
19 words
The method of claim 2 wherein the inversion time of the slice-selective inversion RF pulse is between 100-450 msec.
Claim 5
Dependent Claim
60 words
The method of claim 1 wherein the notched inversion RF pulse has a pass-band and a stop-band, the pass-band designed wide enough to invert regions outside of the region-of-interest to suppress blood that may flow into the region-of-interest when acquiring MR data, and the stop-band designed such that it occurs spatially co-incident with that of the slice-selective inversion RF pulse.
Claim 6
Dependent Claim
16 words
The method of claim 1 further comprising the step of detecting presence of infarcted myocardial tissue.
Claim 7
Dependent Claim
28 words
The method of claim 1 further comprising the step of waiting 5-15 minutes between administering the contrast agent and applying the pulse sequence for myocardial tissue viability assessment.
Claim 8
Dependent Claim
27 words
The method of claim 1 wherein the step of acquiring MR data is further defined as acquiring single-image MR data during a single breath-hold by the patient.
Claim 9
Dependent Claim
19 words
The method of claim 1 wherein MR data is acquired during mid-diastole of an R-R interval of the patient.
Claim 10
Dependent Claim
78 words
An MR pulse sequence comprising: a primary slice-selection inversion RF pulse having a pass-band greater in width than that of an image slice pulse; a notched inversion RF pulse following the primary slice-selection inversion RF pulse and having a stop-band co-incident with that of the primary slice-selection inversion RF pulse; and at least one image slice pulse for a segmented k-space gradient echo imaging segment acquisition separated an inversion time TI BSP from the notched inversion RF pulse.
Claim 11
Dependent Claim
78 words
An MR pulse sequence comprising: a primary slice-selection inversion RF pulse having a pass-band greater in width than that of an image slice pulse; a notched inversion RF pulse following the primary slice-selection inversion RF pulse and having a stop-band co-incident with that of the primary slice-selection inversion RF pulse; and at least one image slice pulse for a segmented k-space gradient echo imaging segment acquisition separated an inversion time TI BSP from the notched inversion RF pulse.
Claim 12
Dependent Claim
25 words
The MR pulse sequence of claim 9 wherein the primary slice-selection inversion RF pulse is designed to suppress normal myocardial tissue in an MR exam.
Claim 13
Dependent Claim
20 words
The MR pulse sequence of claim 9 wherein the notched inversion RF pulse has a flip angle of approximately 90°-180°.
Claim 14
Dependent Claim
37 words
The MR pulse sequence of claim 9 wherein the stop-band of the notched inversion RF pulse is centered over the imaging RF pulse such that an imaged slice is not affected by the notched inversion RF pulse.
Claim 15
Dependent Claim
33 words
The MR pulse sequence of claim 9 wherein an inversion time TI of the primary slice-selection inversion RF pulse is greater than the inversion time TI BSP of the notched inversion RF pulse.
Claim 16
Dependent Claim
26 words
The MR pulse sequence of claim 9 wherein the notched inversion RF pulse has a pass-band to invert blood pool in a region-of-interest during data acquisition.
Claim 17
Dependent Claim
46 words
The MR pulse sequence of claim 14 wherein the inversion time TI BSP of the notched inversion RF pulse is chosen such that blood inverted in the pass-band of the notched inverted RF pulse is at or close to nullification during a gradient echo read-out segment.
Claim 18
Dependent Claim
134 words
An MRI apparatus to improve myocardial infarction detection comprising: a magnetic resonance imaging (MRI) system having a plurality of gradient coils positioned about a bore of a magnet to impress a polarizing magnetic field and an RF transceiver system and an RF switch controlled by a pulse module to transmit RF signals to an RF coil assembly to acquire MR images; and a computer programmed to: transmit a slice-selection inversion pulse to suppress signals from normal myocardial tissue; transmit a notched inversion RF pulse with an inversion time selected to invert regions inside and outside a desired imaging slice such that signals from blood flowing into the desired imaging slice are suppressed; transmit excitation RF pulses; and acquire data from the desired imaging slice having signal suppression from both normal myocardial tissue and blood.
Claim 19
Dependent Claim
134 words
An MRI apparatus to improve myocardial infarction detection comprising: a magnetic resonance imaging (MRI) system having a plurality of gradient coils positioned about a bore of a magnet to impress a polarizing magnetic field and an RF transceiver system and an RF switch controlled by a pulse module to transmit RF signals to an RF coil assembly to acquire MR images; and a computer programmed to: transmit a slice-selection inversion pulse to suppress signals from normal myocardial tissue; transmit a notched inversion RF pulse with an inversion time selected to invert regions inside and outside a desired imaging slice such that signals from blood flowing into the desired imaging slice are suppressed; transmit excitation RF pulses; and acquire data from the desired imaging slice having signal suppression from both normal myocardial tissue and blood.
Claim 20
Dependent Claim
32 words
The MRI apparatus of claim 16 wherein the computer is further programmed to: receive input indicative of contrast agent administration; and allow contrast agent concentration in infarcted regions before the pulse transmissions.
Claim 21
Dependent Claim
28 words
The MRI apparatus of claim 16 wherein the slice-selection inversion pulse has a pass-band designed to account for cardiac and respiratory motion during a primary inversion time TI.
Claim 22
Dependent Claim
47 words
The MRI apparatus of claim 16 wherein the slice-selective inversion RF pulse has a section thickness about 1 and 3 times that of a section thickness of an imaged slice and has an inversion time selected to null signal from normal myocardial tissue of approximately 100-450 msec.
Claim 23
Dependent Claim
26 words
The MRI apparatus of claim 16 wherein the notched inversion RF pulse has a stop-band that is spatially co-incident with that of the slice-selective inversion pulse.
Claim 24
Dependent Claim
21 words
The MRI apparatus of claim 16 wherein data is acquired mid-diastole for each image during a single breath-hold by the patient.
References Cited (Backward Citations)
US5999839A
Cited
US6205349B1
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2006-02-24 | 2006-08-26 | 2007-02-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2010-02-24 | 2010-08-26 | 2011-02-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2014-02-24 | 2014-08-26 | 2015-02-25 | $7700.00 | Window Closed / Lapsed |