PULSE SEQUENCES FOR LOW FIELD MAGNETIC RESONANCE
A low-field magnetic resonance imaging (MRI) system. The system includes a plurality of magnetics components comprising at least one first magnetics component configured to produce a low-field main magnetic field B 0 and at least one second magnetics component configured to acquire magnetic resonance data when operated, and at least one controller configured to operate one or more of the plurality of magnetics components in accordance with at least one low-field zero echo time (LF-ZTE) pulse sequence.
1 . A method of operating a magnetic resonance imaging (MRI) system comprising an RF coil for transmitting and/or receiving RF pulses, the method comprising:
generating a radio frequency (RF) pulse in accordance with a pulse sequence;
pre-emphasizing the RF pulse to counteract attenuation to be induced to the RF pulse by the RF coil to obtain a pre-emphasized RF pulse; and
transmitting the pre-emphasized RF pulse using the RF coil,
wherein pre-emphasizing the RF pulse comprises applying a pre-emphasis transformation to the RF pulse.
2 . The method of claim 1 , wherein the pre-emphasis transformation is based on a transfer function of the RF coil.
3 . The method of claim 1 , wherein applying the pre-emphasis transformation comprises applying an inverse of the transfer function of the transmit RF coil to the RF pulse.
4 . The method of claim 1 , wherein pre-emphasizing the RF pulse comprises pre-emphasizing the RF pulse in a time domain.
5 . The method of claim 1 , wherein pre-emphasizing the RF pulse comprises pre-emphasizing the RF pulse in a frequency domain.
6 . A magnetic resonance imaging (MRI) system, comprising:
a magnetics system configured to produce magnetic fields for performing MRI, the magnetics system including an RF coil for transmitting and/or receiving RF pulses; and
at least one controller configured to operate one or more components of the MRI system to perform:
generating a radio frequency (RF) pulse in accordance with a pulse sequence;
pre-emphasizing the RF pulse to counteract attenuation to be induced to the RF pulse by the RF coil to obtain a pre-emphasized RF pulse; and
transmitting the pre-emphasized RF pulse using the RF coil,
wherein pre-emphasizing the RF pulse comprises applying a pre-emphasis transformation to the RF pulse.
7 . The MRI system of claim 6 , wherein the pre-emphasis transformation is based on a transfer function of the RF coil.
8 . The MRI system of claim 6 , wherein applying the pre-emphasis transformation comprises applying an inverse of the transfer function of the transmit RF coil to the RF pulse.
9 . The MRI system of claim 6 , wherein pre-emphasizing the RF pulse comprises pre-emphasizing the RF pulse in a time domain.
10 . The MRI system of claim 6 , wherein pre-emphasizing the RF pulse comprises pre-emphasizing the RF pulse in a frequency domain.
11 . The MRI system of claim 6 , wherein the magnetics system includes at least one B 0 magnet to generate a B 0 magnetic field having a strength less than 0.2 T.
12 . The MRI system of claim 6 , wherein the magnetics system includes at least one B 0 magnet to generate a B 0 magnetic field having a strength in a range from 25 μT to 0.1 T.
13 . The MRI system of claim 6 , wherein the magnetics system further includes a plurality of gradient coils configured to, when operated, generate magnetic fields to provide spatial encoding of emitted magnetic resonance signals.
14 . A magnetic resonance imaging (MRI) system comprising:
a magnetics system configured to produce magnetic fields for performing MRI, the magnetics system including an RF coil for transmitting and/or receiving RF pulses; and
at least one controller configured to operate one or more components of the MRI system to perform:
generating a radio frequency (RF) pulse in accordance with a pulse sequence;
pre-emphasizing the RF pulse based on a characteristic of the RF coil to obtain a pre-emphasized RF pulse; and
transmitting the pre-emphasized RF pulse using the RF coil.
15 . The MRI system of claim 14 , wherein pre-emphasizing the RF pulse comprises applying an inverse of the RF coil to the RF signal.
16 . The MRI system of claim 14 , wherein pre-emphasizing the RF pulse is performed based on a transfer function of the RF coil.
17 . The MRI system of claim 14 , wherein pre-emphasizing the RF pulse comprises pre-emphasizing the RF pulse in a time domain.
18 . The MRI system of claim 14 , wherein pre-emphasizing the RF pulse comprises pre-emphasizing the RF pulse in a frequency domain.
19 . The MRI system of claim 14 , wherein the magnetics system includes at least one B 0 magnet to generate a B 0 magnetic field having a strength less than 0.2 T.
20 . The MRI system of claim 14 , wherein the magnetics system includes at least one B 0 magnet to generate a B 0 magnetic field having a strength in a range from 25 μT to 0.1 T.