SYSTEM AND METHOD FOR REAL-TIME NOISE REDUCTION IN MRI DATA ACQUISITION
A system for determining the level of shielding in a magnetic resonance imaging (MRI) apparatus and for real-time reduction of noise produced during MRI data acquisition. The system includes: at least one antenna; data acquirer in communication with the at least one antenna and in communication with the RF pulse generator; and a synchronizer for synchronizing the acquisition of data by the data acquirer with MRI pulses being produced by the MRI apparatus.
1 . A system for determining the level of shielding in an MRI apparatus and for real-time reduction of noise produced during MRI data acquisition in an MRI apparatus comprising RF pulse generating means for generating RF pulses for MRI data acquisition and a cavity, wherein said system comprises:
at least one antenna in location selected from the group consisting of (a) in proximity to said MRI apparatus and (b) within the cavity of said MRI apparatus;
data acquisition means in communication with at least one antenna and in communication with said RF pulse generating means; and,
synchronizing means for synchronizing the acquisition of data by said data acquisition means with MRI pulses being produced by said MRI apparatus.
2 . The system according to claim 1 , wherein said system comprises a first antenna located in proximity to said MRI apparatus and a second antenna located within the cavity of said MRI apparatus.
3 . The system according to claim 1 , wherein at least one of said antennas comprises three orthogonally oriented loop antennas.
4 . The system according to claim 1 , wherein at least one of said is an omnidirectional antenna.
5 . The system according to claim 1 , wherein said second antenna is not located within a field of view of said apparatus.
6 . The system according to claim 1 , wherein said MRI apparatus comprises a permanent magnet.
7 . The system according to claim 1 , comprising data manipulation means configured for producing a residual signal obtained by said at least one antenna from which signals arising from said RF pulse generating means have been eliminated.
8 . A method for real-time reduction of noise during MRI data acquisition in an MRI apparatus comprising RF pulse generating means for generating RF pulses and a cavity, comprising:
placing at least one antenna in a location selected from the group consisting of (a) in proximity to said MRI apparatus and (b) within the cavity of said MRI apparatus;
connecting said antennas with data acquisition means and with said RF pulse generating means;
synchronizing data acquisition with at least one RF pulse or set of MRI pulses produced by said RF pulse generating means to produce a data subset;
determining residual noise measured by at least one of said antennas after said step of synchronizing; and,
if said residual noise is above a predetermined threshold, performing a step chosen from the group consisting of:
subtracting said residual noise from an MRI signal obtained following said MRI pulse or set of MRI pulses;
repeating said MRI pulses to obtain said data subset; and,
deleting said data subset from a data set acquired during said MRI data acquisition.
9 . The method according to claim 8 , wherein said step of placing at least one antenna in a location selected from the group consisting of (a) in proximity to said MRI apparatus and (b) within the cavity of said MRI apparatus comprises placing a first antenna in proximity to said MRI apparatus and placing a second antenna within the cavity of said MRI apparatus.
10 . The method according to claim 9 , wherein said step of placing a second antenna within the cavity of said MRI apparatus comprises placing said second antenna outside of a field of view of said MRI apparatus.
11 . The method according to claim 8 , wherein said step of placing at least one antenna in a location selected from the group consisting of (a) in proximity to said MRI apparatus and (b) within the cavity of said MRI apparatus comprises placing an antenna comprising three orthogonal loop antennas.
12 . The method according to claim 8 , said step of placing at least one antenna in a location selected from the group consisting of (a) in proximity to said MRI apparatus and (b) within the cavity of said MRI apparatus comprises placing at least one omindirectional antenna.
13 . The method according to claim 8 , wherein said MRI apparatus is a permanent magnet MRI apparatus.
14 . A method for determining the level of RF shielding in an MRI apparatus comprising RF pulse generating means for generating RF pulses and a cavity, comprising:
placing a first antenna in proximity to said MRI apparatus;
placing a second antenna within the cavity of said MRI apparatus;
connecting said antennas with data acquisition means and with said RF pulse generating means;
synchronizing data acquisition by said data acquisition means with at least one RF pulse or set of MRI pulses produced by said RF pulse generating means to produce a data subset;
determining residual noise measured by each of said antennas after said step of synchronizing; and,
comparing the residual noise obtained by each of said antennas, thereby determining the level of RF shielding.