Patent Description:
Magnetic resonance imaging (MRI) is an imaging technique used in radiology to form images of the anatomy and the physiological processes of an object (e.g., a patient, or a section thereof). MRI scanners use strong magnetic fields, radio waves, and field gradients to generate images of the inner structure of the object based on the science of nuclear magnetic resonance (NMR). More particularly, certain atomic nuclei (e.g., hydrogen-<NUM>, carbon-<NUM>, oxygen-<NUM>, etc.) absorb and emit RF energy when placed in an external magnetic field. The emitted RF energy exists as RF signals and is received by the MRI scanners.

Hydrogen atoms are often used to generate a detectable RF signal that is received by an antenna of a coil in close proximity to the object being examined. Conventionally, the antenna includes capacitance, conductance, and/or resistance that provide the antenna a specific resonant frequency. When the frequency of the RF signal emitted from the object matches the resonant frequency of the antenna, the antenna resonates and receives the RF signal. Hence, the antenna has to be designed carefully so that the resonant frequency exactly matches the frequency of the RF signal emitted from the object. However, the antenna is usually deformed (bent) in use and the resonant frequency changes. When the resonant frequency no longer matches the frequency of the RF signal emitted from the object, the coil does not work as well as before and the RF signal is received at a lower quality (e.g., with a lower signal-to-noise ratio (SNR)). Therefore, it is desired to develop a coil that is able to receive the RF signal even when it is deformed.

<CIT> discloses antenna assemblies for magnetic resonance signals comprising non-resonant loop antenna and a high impedance differential amplifier. The amplifier can include first and second high electron mobility transistor that have gates coupled to an antenna loop that is defined on a rigid substrate. The non-resonant loop has an effective length of less than about <NUM>/<NUM> of a wavelength of a signal to be detected. Arrays of such loops can be defined on the rigid substrate and HEMTs for the loops secured to the substrate.

<NPL> discloses a non-resonant wideband NMR probe. The probe has a saddle coil geometry and is designed such that the coil itself forms a transmission line. The probe thus requires no tuning or matching elements. The probe is used with a spectrometer whose duplexer circuitry employs a simple RF switch instead of the more common λ/<NUM> lines so that the entire probe and spectrometer perform in an essentially frequency-independent manner. The probe performs well at frequencies up to <NUM> and beyond.

<CIT> discloses a system for MR signal excitation and reception and a method which uses a non-resonant device or transmission line to perform MR imaging and spectroscopy. The system with non-resonant device is advantageous to parallel imaging due to the improved decoupling performance. Because the non-resonant RF coil is not generally sensitive to frequency a MR system with the non-resonant RF coil is capable of multinuclear MR operation at varied magnetic field strength. They system comprises a non-resonant RF coil for connecting to an MR system the conductor being configured to have a characteristic impedance matched to the MR system. The RF coil is configured to produce electromagnetic fields of different strength based on the constant characteristic impedance maintained in the system for exciting and receiving MR signals.

<CIT> discloses a method and a system of applying nuclear magnetic resonance (NMR) sequences to a substance. The method includes applying an NMR pulse sequence to the substance using a non-resonant transmitter circuit. The NMR pulse sequence includes a first pulse sequence segment applied at a first frequency to a first shell within the substance and a second pulse sequence segment applied at a second frequency to a second shell. The second pulse sequence segment is initiated before the first shell reaches thermal equilibrium. In some cases the first pulse sequence segment and the second pulse sequence segment are interposed within each other. Such NMR pulse sequences, with multiple pulse sequence segments can also be applied to different atomic nuclei.

<CIT> discloses methods and systems for tools having non-resonance circuits for analyzing a formation and/or a sample. For example, nuclear magnetic resonance and resistivity tools can make use of a non-resonant excitation coil and/or a detection coil. These coils can achieve desired frequencies by the use of switches, thereby removing the requirement of tuning circuits that are typical in conventional tools.

In accordance with a first aspect of the invention there is provided a magnetic resonance coil having all of the features of claim <NUM> of the appended claims.

In an aspect of the present disclosure, a magnetic resonance coil is provided. The magnetic resonance coil may include an antenna configured to receive a radio frequency (RF) signal emitted from an object, wherein the antenna does not resonate with the RF signal. The magnetic resonance coil may further include a signal processor coupled to the antenna configured to process the RF signal to generate a processed signal.

In some embodiments, the antenna is a non-resonant antenna.

In some embodiments, the antenna may be a birdcage structure configured to receive the RF signal from an entire body of the object.

In some embodiments, the antenna may be a loop structure configured to receive the RF signal from a portion of the object.

In some embodiments, the signal processor may include an amplifier coupled to the antenna and configured to amplify the RF signal.

In some embodiments, the magnetic resonance coil may further include a matching circuit coupled between the antenna and the amplifier and configured to match an impedance of the antenna and an impedance of the amplifier.

In some embodiments, the matching circuits is a broadband matching circuit that matches the impedance of the antenna and the impedance of the amplifier over a frequency range of the broadband signals.

In some embodiments, the magnetic resonance coil may further include an adjusting circuit coupled to the amplifier and configured to adjust the magnitude of the imaginary part of impedance of the amplifier.

In some embodiments, the signal processor may further include a heterodyne receiver or a homodyne receiver coupled to the amplifier.

In some embodiments, the signal processor is a direct sampling structure, and the signal processor may include an analog-to-digital converter configured to convert the RF signal to a digital signal.

In some embodiments, the antenna may be configured without capacitive elements on conductive materials.

In some embodiments, the antenna may be configured with no impedance matching circuit.

In some embodiments, the antenna may be configured with no coupling unit, nor decoupling unit.

In some embodiments, the magnetic resonance coil may be implemented in a multi-nuclear magnetic resonance system relating to a plurality of atomic nuclei. The plurality of atomic nuclei may include phosphorus atom or sodium atom.

A magnetic resonance imaging (MRI) system is provided. The MRI system may include a main electromagnet configured to generate a uniform magnetic field on an object, and a gradient electromagnet configured to generate a gradient magnetic field on the object. The MRI system may further include a transmitting coil configured to transmit a first radio frequency (RF) signal to the object, and a receiving coil configured to receive and process a second RF signal emitted from the object in response to the first RF signal. The receiving coil may include an antenna configured to receive a radio frequency (RF) signal emitted from an object, wherein the antenna does not resonate with the RF signal. The receiving coil may further include a signal processor coupled to the antenna configured to process the RF signal to generate a processed signal. The MRI system may include a processor configured to generate an image of the object based on the processed signal. The MRI system may include a display configured to display the generated image of the object.

These embodiments are non-limiting examples, in which like reference numerals represent similar structures throughout the several views of the drawings, and wherein:.

In the following detailed description, numerous specific details are set forth by way of examples in order to provide a thorough understanding of the relevant disclosure. However, it should be apparent to those skilled in the art that the present disclosure may be practiced without such details. In other instances, well-known methods, procedures, systems, components, and/or circuitry have been described at a relatively high-level, without detail, in order to avoid unnecessarily obscuring aspects of the present disclosure. Various modifications to the disclosed embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other embodiments and applications without departing from the scope of the present disclosure. Thus, the present disclosure is not limited to the embodiments shown, but to be accorded the widest scope consistent with the claims.

It will be understood that the term "system," "unit," "module," and/or "block" used herein are one method to distinguish different components, elements, parts, section or assembly of different level in ascending order. However, the terms may be displaced by another expression if they may achieve the same purpose.

It will be understood that when a unit, module or block is referred to as being "on," "connected to" or "coupled to" another unit, module, or block, it may be directly on, connected or coupled to the other unit, module, or block, or intervening unit, module, or block may be present, unless the context clearly indicates otherwise.

The terminology used herein is for the purposes of describing particular examples and embodiments only, and is not intended to be limiting. It will be further understood that the terms "include," and/or "comprise," when used in this disclosure, specify the presence of integers, devices, behaviors, stated features, steps, elements, operations, and/or components, but do not exclude the presence or addition of one or more other integers, devices, behaviors, features, steps, elements, operations, components, and/or groups thereof.

The present disclosure provides a magnetic resonance coil implemented in an MRI system. The present magnetic resonance coil may receive an RF signal generated by an object being examined even when it is deformed. The magnetic resonance coil may include an antenna that does not resonate with the RF signal and a signal processor coupled to the antenna configured to process the RF signal. In some embodiments, different atoms may emit RF signals at different frequencies. As the non-resonant RF antenna may receive RF signals at a wide range of frequencies, it may be used to image atoms, such as a phosphorus atom, a sodium atom, etc. besides the atoms that are commonly imaged in an MRI system (e.g., hydrogen atoms, carbon atoms, oxygen atoms). The antenna may be a birdcage structure configured to receive the RF signal from an entire body of the object or may be a loop structure configured to receive the RF signal from a portion of the object. The signal processor may be an analog signal processor or a digital signal processor. The signal processor may include an amplifier configured to amplify the received RF signal. The magnetic resonance coil may include an adjusting circuit configured to adjust the magnitude of the imaginary part of impedance of the amplifier. The input impedance of the amplifier may be greater than <NUM> Ohms.

<FIG> is a schematic block diagram of an exemplary magnetic resonance imaging (MRI) system <NUM> according to some embodiments of the present disclosure. As shown in <FIG>, the MRI system <NUM> may include a MRI scanner <NUM>, a computing device <NUM>, a processing engine <NUM>, and a storage device <NUM>. It should be noted that the imaging system described below is merely provided for illustration purposes, and not intended to limit the scope of the present disclosure. The MRI system <NUM> may find its applications in various fields, such as healthcare industries (e.g., medical applications), security applications, industrial applications, etc. For example, the MRI system <NUM> may be used for analyzing composition of a specimen, nuclear magnetic resonance logging, or the like, or a combination thereof.

The MRI scanner <NUM> may include a main magnet <NUM>, a gradient magnet <NUM>, a volume coil <NUM>, a local coil <NUM>, a scanning bed <NUM>, an pulse controller <NUM>, a gradient signal generator <NUM>, a first gradient amplifier <NUM>, a second gradient amplifier <NUM>, a third gradient amplifier <NUM>, an RF pulse generator <NUM>, a switch <NUM>, and an RF signal receiver <NUM>. A detecting region <NUM> may be formed in the MRI scanner <NUM>. The detecting region <NUM> may be a place where the object is scanned by the MRI scanner <NUM>.

The MRI scanner <NUM> may be configured to scan an imaging object <NUM>. The MRI scanner <NUM> may obtain information related to the imaging object <NUM> by scanning the imaging object <NUM>. More particularly, certain atomic nuclei (e.g., hydrogen-<NUM>, carbon-<NUM>, oxygen-<NUM>, etc.) may absorb and emit RF energy when being placed in the main magnetic <NUM> and the gradient magnet <NUM>. The emitted RF energy exists as RF signals and is received by the MRI scanner <NUM>. The MRI scanner <NUM> may reconstruct a distribution of the atomic nuclei inside the imaging object based on the RF signals as an MRI image.

The main magnet <NUM> may be placed in a gantry <NUM> of the MRI scanner. The main magnet <NUM> may be configured to generate a uniform main magnetic field. The strength of the main magnetic field may be <NUM> Tesla, <NUM> Tesla, <NUM> Tesla, <NUM> Tesla, <NUM> Tesla, etc. In some embodiments, the main magnet <NUM> may be a superconducting coil. Alternatively, the main magnet <NUM> may be a permanent magnet.

The scanning bed <NUM> may support the imaging object <NUM> during a scan. The object may be biological or non-biological. Merely by way of example, the object may include a patient, an organ, a specimen, a man-made object, a mold, etc. During a scan, the imaging object <NUM> may be supported and delivered to the detecting region <NUM> of the gantry <NUM> by the scanning bed <NUM>. The detecting region <NUM> may be a region that the magnetic field distribution of the main magnetic field is relatively uniform, and to which, the RF signal is transmitted.

Merely by way of example, a spatial coordinate system (i.e., a coordinate system of the MRI scanner) may be described relative to the gantry <NUM> of the MRI scanner <NUM>. For example, a Z axis may be the direction along the axis of the gantry, an X axis and a Y axis may be the directions perpendicular to the Z axis. The long-axis direction of the imaging object may coincide with the direction of the Z axis and the scanning bed <NUM> may move in the direction of the Z axis.

The pulse controller <NUM> may be configured to control the generation of RF signals. For example, the pulse controller <NUM> may control the RF pulse generator <NUM> and the gradient signal generator <NUM>. In some embodiments, the pulse controller <NUM> may control the RF pulse generator <NUM> to generate an RF pulse. The RF pulse may be amplified by an amplifier. In some embodiments, the pulse controller <NUM> may control the gradient signal generator <NUM> to generate gradient signals.

The pulse controller <NUM> may receive information from or send information to the MRI scanner, the processing engine <NUM>, and/or a display <NUM>. According to some embodiments of the present disclosure, the pulse controller <NUM> may receive a command from a user via the display <NUM> and control components of the MRI scanner (e.g., the RF pulse generator <NUM>) accordingly to start a scan.

The RF pulse generator <NUM> may generate an RF pulse. In some embodiments, the RF pulse generator <NUM> may generate the RF pulse based on an instruction from the pulse controller <NUM>. The RF pulse may be amplified by an amplifier. The switch <NUM> may be configured to control the emission of the amplified RF pulse. For example, the amplified RF pulse may be emitted by the volume coil <NUM> and/or the local coil <NUM> when the switch <NUM> is on. The emitted RF pulse may excite the atomic nuclei in the imaging object <NUM>. The imaging object <NUM> may generate a corresponding RF signal when the RF excitation is removed. The volume coil <NUM> and/or the local coil <NUM> may transmit RF signals to or receive RF signals from the imaging object <NUM>. For example, the volume coil <NUM> and/or the local coil <NUM> may transmit the amplified RF pulse to the imaging object <NUM>. For another example, the volume coil <NUM> and/or the local coil <NUM> may receive the RF signal emitted from the imaging object <NUM>. In some embodiments, the volume coil <NUM> and/or the local coil <NUM> may include a plurality of RF receiving channels. The plurality of RF receiving channels may transmit RF signals received from the imaging object <NUM> to the RF signal receiver <NUM>. In some embodiments, the volume coil <NUM> may be configured to transmit RF signals to or receive RF signals from the entire body of the imaging object <NUM> while the local coil <NUM> may be configured to transmit RF signals to or receive RF signals from a portion of the imaging object <NUM>.

The volume coil <NUM> and/or the local coil <NUM> may be magnetically-insulated. In some embodiments, the volume coil <NUM> and the local coil <NUM> are non-resonant coils which do not include any capacitance. The volume coil <NUM> and/or the local coil <NUM> may be made of one or more deformable materials. For example, the volume coil <NUM> and/or the local coil <NUM> may be made of shape-memory alloy. The shape-memory alloy may recover to its original shape under a recovering condition (e.g., a high temperature, a large strain). The shape-memory alloy may include silver, cadmium, gold, nickel, titanium, hafnium, copper, zinc, or the like, or any combination thereof. For another example, the volume coil <NUM> and/or the local coil <NUM> may be made of deformable conductive materials. The deformable conductive materials may include metallic materials such as solid metals, alloys, liquid metals, etc. The liquid metals may include mercury, aluminum, cesium, gallium, rubidium, or the like, or any combination thereof.

In some embodiments, the volume coil <NUM> may be a large coil (e.g., a birdcage coil) that can accommodate the entire body of the imaging object <NUM>. The local coil <NUM> may be a small coil (e.g., a loop coil, a solenoid coil, a saddle coil, a flexible coil, etc.) that covers a portion of the imaging object <NUM>.

The RF signal receiver <NUM> may be configured to receive RF signals. The RF signal receiver <NUM> may receive RF signals from the volume coil <NUM> and/or the local coil <NUM>.

The gradient signal generator <NUM> may generate gradient signals. In some embodiments, the gradient signal generator <NUM> may generate gradient signals based on an instruction from the pulse controller <NUM>. The gradient signals may include three orthogonal signals. In some embodiments, the three orthogonal signals may be a first gradient signal along the X direction, a second gradient signal along the Y direction, and a third gradient signal along the Z direction. The gradient signals may help to locate the atomic nuclei.

The first gradient amplifier <NUM>, the second gradient amplifier <NUM>, and the third gradient amplifier <NUM> may be configured to amplify the gradient signals generated by the gradient signal generator <NUM>. In particular, the first gradient amplifier <NUM> may amplify the first gradient signal, the second gradient amplifier <NUM> may amplify the second gradient signal, and the third gradient amplifier <NUM> may amplify the third gradient signal, respectively.

The gradient magnet <NUM> (also called gradient coil <NUM>) may be configured to spatially encode RF signals (e.g., an RF pulse generated by the RF pulse generator <NUM>). The gradient magnet <NUM> may generate a magnetic field with a strength less than that of the main magnetic field. For example, the gradient magnet <NUM> may generate a gradient magnet field in the detecting region <NUM>.

In some embodiments, the MRI scanner <NUM> may include both a volume coil <NUM> and a local coil <NUM>. For example, the volume coil <NUM> may be configured to emit RF signals, and the local coil may be configured to receive RF signals, or vice versa. The volume coil <NUM> and the local coil <NUM> may each include an amplifier with a high input impedance value, respectively. The amplifiers with high input impedance may decouple the volume coil and the local coil without additional decoupling methods.

The computing device <NUM> may include a reconstruction module <NUM>, the display <NUM>, an input/output (I/O) <NUM>, and a communication port <NUM>.

The reconstruction module <NUM> may be configured to reconstruct an MRI image. The reconstruction module <NUM> may reconstruct an MRI image based on RF signals received by the RF signal receiver <NUM>.

The display <NUM> may be configured to display images. The display <NUM> may include a liquid crystal display (LCD), a light emitting diode (LED)-based display, or any other flat panel display, or may use a cathode ray tube (CRT), a touch screen, or the like. A touch screen may include, e.g., a resistor touch screen, a capacity touch screen, a plasma touch screen, a vector pressure sensing touch screen, an infrared touch screen, or the like, or a combination thereof.

The I/O <NUM> may input and/or output signals, data, information, etc. The input and/or output information may include programs, software, algorithms, data, text, number, images, voice, or the like, or any combination thereof. For example, a user or an operator may input some initial parameters or conditions to initiate a scan. As another example, some information may be imported from an external resource, such as a floppy disk, a hard disk, a wireless terminal, or the like, or any combination thereof. In some embodiments, the I/O <NUM> may enable a user interaction with the processing engine <NUM>. In some embodiments, the I/O <NUM> may include an input device and an output device. Examples of the input device may include a keyboard, a mouse, a touch screen, a control box, a microphone, or the like, or a combination thereof. Examples of the output device may include a display device, a loudspeaker, a printer, a projector, or the like, or a combination thereof.

The communication port <NUM> may be connected to a network (not shown) to facilitate data communications. The communication port <NUM> may establish connections between an external device, an image acquisition device, a database, an external storage, and an image processing workstation, etc. The connection may be a wired connection, a wireless connection, any other communication connection that can enable data transmission and/or reception, and/or any combination of these connections. The wired connection may include, for example, an electrical cable, an optical cable, a telephone wire, or the like, or any combination thereof. The wireless connection may include, for example, a Bluetooth™ connection, a Wi-Fi™ connection, a WiMax™ connection, a WLAN connection, a ZigBee connection, a mobile network connection (e.g., <NUM>, <NUM>, <NUM>, etc.), or the like, or a combination thereof. In some embodiments, the communication port <NUM> may include a standardized communication port, such as RS232, RS485, etc. In some embodiments, the communication port <NUM> may be a specially designed communication port. For example, the communication port <NUM> may be designed in accordance with the digital imaging and communications in medicine (DICOM) protocol.

The processing engine <NUM> may process different kinds of information. For example, the processing engine <NUM> may process RF signals received from the RF signal receiver <NUM> to the reconstruction module <NUM> to generate one or more images based on these signals and sent the images to the display <NUM>. In some embodiments, the processing engine <NUM> may process data input by a user or an operator via the display <NUM> and/or the I/O <NUM>, transform the data into specific commands, and supply the commands to the pulse controller <NUM>. The processing engine <NUM> may include one or more processors.

The storage device <NUM> may store data relating to the MRI system <NUM>. The data may be data files related to processing and/or communication, program command to be executed by the processor engine <NUM>, a numerical value, an image, information of an object, an instruction and/or a signal to operate the MRI system <NUM>, voice, a model relating to a patient, an algorithm relating to an image processing technique, or the like, or a combination thereof. Exemplary numerical values may include a threshold, a MR value, a value relating to a coil, or the like, or a combination thereof. Exemplary images may include a raw image or a processed image (e.g., an image after pretreatment). Exemplary models relating to a patient may include the background information of the patient, such as, ethnicity, citizenship, religion, gender, age, matrimony state, height, weight, medical history (e.g., history relating to different organs, or tissues), job, personal habits, or the like, or a combination thereof.

The storage device <NUM> may include a random access memory (RAM), a read-only memory (ROM), or the like, or a combination thereof. The random access memory (RAM) may include a dekatron, a dynamic random access memory (DRAM), a static random access memory (SRAM), a thyristor random access memory (T-RAM), a zero capacitor random access memory (Z-RAM), or the like, or a combination thereof. The read only memory (ROM) may include a bubble memory, a magnetic button line memory, a memory thin film, a magnetic plate line memory, a core memory, a magnetic drum memory, a CD-ROM drive, a hard disk, a flash memory, or the like, or a combination thereof. The storage device <NUM> may be a removable storage device such as a chip disk that may read data from and/or write data to the reconstruction module <NUM> in a certain manner. The storage device <NUM> may also include other similar means for providing computer programs or other instructions to operate the modules/units in the MRI system <NUM>. The storage device <NUM> may be operationally connected to one or more virtual storage resources (e.g., a cloud storage, a virtual private network, other virtual storage resources, etc.) for transmitting or storing the data into the one or more virtual storage resources.

In some embodiment, the pulse controller <NUM>, the reconstruction module <NUM>, the processing engine <NUM>, the display <NUM>, the I/O <NUM>, the storage device <NUM>, and the communication port <NUM> may transmit data to each other via a communication bus <NUM> to control an imaging process of the MRI scanner <NUM>.

This description is intended to be illustrative, and not to limit the scope of the present disclosure. Many alternatives, modifications, and variations will be apparent to those skilled in the art. The features, structures, methods, and other characteristics of the exemplary embodiments described herein may be combined in various ways to obtain additional and/or alternative exemplary embodiments. For example, the storage device <NUM> may be a database including cloud computing platforms, such as a public cloud, a private cloud, a community and hybrid clouds, etc. As another example, the pulse controller <NUM>, the processing engine <NUM>, and/or the display <NUM> may be integrated into an MRI console (not shown). Users may set parameters in MRI scanning, control the imaging procedure, view the images produced through the MRI console. However, those variations and modifications do not depart the scope of the present disclosure.

<FIG> is a flowchart illustrating an exemplary process for processing an RF signal according to some embodiments of the present disclosure. In some embodiments, a process <NUM> may be implemented in the MRI system <NUM> as illustrated in <FIG>.

In <NUM>, an RF signal emitted from an object may be received by an RF receiving coil. The RF receiving coil may be a non-resonant coil. The object may be biological or non-biological. Merely by way of example, the object may include a patient, an organ, a specimen, a man-made object, a mold, etc. The RF signal may be an analog signal or a digital signal. As mentioned in <FIG>, the object may be placed in a magnetic field and a volume coil <NUM> and/or a local coil <NUM> may transmit an RF signal to the object. The transmitted RF signal may excite atomic nuclei in the imaging object <NUM>. The imaging object <NUM> may generate a corresponding RF signal when the RF excitation is removed. The object may emit the RF signal based on relaxation properties of atomic nuclei therein. The atomic nuclei may include hydrogen-<NUM>, carbon-<NUM>, oxygen-<NUM>, sodium <NUM>, phosphorus-<NUM>, or the like, or any combination thereof.

In <NUM>, the received RF signal may be processed to generate a processed signal. In some embodiments, the processing engine <NUM> may first process the RF signal and then convert the processed RF signal to a digital signal. For example, the processing engine <NUM> may amplify the RF signal, filter the amplified RF signal to generate a processed RF signal, and then convert the processed RF signal to a digital signal. In some embodiments, the processing engine <NUM> may convert the RF signal to a digital RF signal before processing the signal. For example, an analog-to-digital converter may be configured to convert the RF signal to a digital signal. Digital signal processing may include procedures of signal amplification, frequency conversion, filtering, notch, or the like, or any combination thereof.

<FIG> is a flowchart illustrating an exemplary process for processing an RF signal according to some embodiments of the present disclosure. In some embodiments, the process <NUM> may be implemented in the MRI system <NUM> as illustrated in <FIG>.

In <NUM>, an RF signal emitted from an object may be received by a RF receiving coil (e.g., volume coil <NUM>, local coil <NUM>, etc.). The RF receiving coil may be a non-resonant coil. The object may be biological or non-biological. Merely by way of example, the object may include a patient, an organ, a specimen, a man-made object, a mold, etc. The RF signal may be an analog signal or a digital signal. As mentioned in <FIG>, the object may be placed in a magnetic field and a volume coil <NUM> and/or a local coil <NUM> may transmit an RF signal to the object. The transmitted RF signal may excite atomic nuclei in the imaging object <NUM>. The imaging object <NUM> may generate a corresponding RF signal when the RF excitation is removed. The object may emit the RF signal based on relaxation properties of atomic nuclei therein. The atomic nuclei may include hydrogen-<NUM>, carbon-<NUM>, oxygen-<NUM>, sodium <NUM>, phosphorus-<NUM>, or the like, or any combination thereof.

In some embodiments, the RF signal may be an analog signal. The RF signal may be converted to a digital signal before further processing (see, e.g., step <NUM> to step <NUM>). In some embodiments, the RF signal may be processed before converted to a digital signal (see, e.g., step <NUM> to step <NUM>).

In <NUM>, the RF signal may be amplified. The processing engine <NUM> may control an amplifier to amplify the RF signal. The amplifier may be coupled to the RF receiving coil. The amplifier may be a low noise amplifier. The low noise amplifier may be a component of an analog signal processor (e.g., an analog signal processor <NUM>). In some embodiments, a matching circuit (e.g., a matching circuit <NUM>) may be configured to match an impedance of the RF receiver with an impedance of the amplifier.

In <NUM>, the amplified RF signal may be filtered to generate a filtered signal. The processing engine <NUM> may control a filter to filter the amplified RF signal. In some embodiments, the filter may be coupled to an amplifier directly. For example, a low-pass filter may be directly connected to the amplifier and filter the amplified RF signal. In some embodiments, the filter may be coupled to a down converter coupled to the amplifier. For example, the filter may be a channel selection filter (or a bandpass filter) coupled to a down converter. In some embodiments, the filer may be a portion of an analog signal processor.

In <NUM>, the filtered signal may be converted to a digital signal. The processing engine <NUM> may control an analog-to-digital converter (e.g., an analog-to-signal converter <NUM>) to convert the filtered signal to a digital signal. In some embodiments, the analog-to-digital converter may be coupled to an analog signal processor.

In <NUM>, the RF signal may be converted to a digital signal. The RF signal may be an analog signal. The processing engine <NUM> may control an analog-to-digital converter to convert the RF signal to a digital signal. The analog-to-digital converter may be coupled to an RF receiving coil directly.

In <NUM>, the digital signal may be processed. The processing engine <NUM> may control a digital signal processor to process the digital signal. The digital processor may be coupled to the analog-to-digital converter. The signal processing may include procedures of signal amplification, frequency conversion, filtering, notch, or the like, or any combination thereof.

It should be noted that the flowchart described above is provided for the purposes of illustration, not intended to limit the scope of the present disclosure. For persons having ordinary skills in the art, multiple variations and modifications may be reduced to practice in the light of the present disclosure. However, those variations and modifications do not depart from the scope of the present disclosure. For example, other analog or digital signal processing methods may be added or may replace the current operations in the process <NUM>.

<FIG> is a schematic diagram illustrating an exemplary magnetic resonance RF coil according to some embodiments of the present disclosure. As shown, the magnetic resonance RF coil <NUM> may include an RF antenna <NUM>, a matching circuit <NUM>, an analog signal processor <NUM>, an analog-to-digital converter <NUM>, a controlling circuit <NUM>, and an energy supplying circuit <NUM>. It should be noted that the magnetic resonance RF coil described herein is merely provided for illustrative purposes, and not intended to limit the scope of the present disclosure. The magnetic resonance RF coil <NUM> may find its applications in various fields, such as healthcare industries (e.g., medical applications), security applications, industrial applications, etc. For example, the magnetic resonance RF coil <NUM> may be used for internal inspections of components including, e.g., flaw detection, security scanning, failure analysis, metrology, assembly analysis, void analysis, wall thickness analysis, or the like, or a combination thereof.

The RF antenna <NUM> may be configured to receive RF signals from an object (e.g., the imaging object <NUM>). In some embodiments, the RF antenna <NUM> may be a non-resonant RF antenna. For example, the RF antenna <NUM> may not include any capacitive components and may not resonant at a fixed frequency. Instead, the RF antenna <NUM> may be configured to resonant and receive signals at a wide range of frequencies (broadband signals). Merely by way of example, an antenna of a <NUM>. 5T MRI system that includes capacitance may resonant at a frequency fixed at, for example, about <NUM>. However, the RF antenna <NUM> may resonant at a frequency range, e.g., from <NUM> to <NUM>. Besides the atoms that are commonly imaged in an MRI system (e.g., hydrogen atoms, carbon atoms, oxygen atoms), the non-resonant RF antenna <NUM> may be used to image atoms, such as a phosphorus atom, a sodium atom, etc. The RF antenna <NUM> may be in a structure of a loop, a solenoid, a saddle, or the like.

The matching circuit <NUM> may be electrically connected to the RF antenna <NUM>. The matching circuit <NUM> may be configured to match the impedance of the RF antenna <NUM> and that of the analog signal processor <NUM> to reduce the noise generated in the RF coil <NUM>. In some embodiments, the matching circuit <NUM> may be a broadband matching circuit which may match the impedance of the radio frequency antenna <NUM> and the analog signal processor <NUM> over a frequency range of the broadband signals.

The analog signal processor <NUM> may be electrically coupled to the matching circuit <NUM>. The analog signal processor <NUM> may be configured to process an analog signal received by the RF antenna <NUM>. For example, the signal process may include procedures of sampling, analog signal amplification, filtering, phase shifting, notch, or the like, or a combination thereof.

The analog-to-digital converter <NUM> may be configured to convert an analog signal to a digital signal. The analog-to-digital converter <NUM> may be configured to pre-process the digital signal. For example, the analog-to-digital converter <NUM> may compress a digital signal. For another example, the analog-to-digital converter <NUM> may adjust a digital signal. The analog-to-digital converter <NUM> may be connected to a cable, a fiber optic or a wireless means, via which the digital signal is to be transmitted.

The controlling circuit <NUM> may be configured to control the analog signal processor <NUM> and the analog-to-digital converter <NUM>. The controlling circuit <NUM> may include a timing circuit with a clock signal. The clock signal may be configured to control an analog-to-digital sampling in the analog-to-digital converter <NUM>. The clock signal may also control the RF coil <NUM> regarding the acquisition of RF signals.

The energy supplying circuit <NUM> may be configured to transmit electrical power (energy) to the analog signal processor <NUM> and the analog-to-digital converter <NUM>. The energy supplying circuit <NUM> may include a battery pack. The battery pack may supply power to the analog signal processor <NUM> and the analog-to-digital converter <NUM>. In some embodiments, the energy supplying circuit <NUM> may be configured to supply power to circuits other than analog signal processor <NUM> and the analog-to-digital converter <NUM> of the RF coil <NUM>. For example, the energy supplying circuit <NUM> may supply power to the controlling circuit <NUM>. In some embodiments, the energy supplying circuit <NUM> may be rechargeable. The energy supplying circuit <NUM> may be recharged by e.g., a portable power supply, a direct current (DC) cable or a wireless charging device.

In some embodiments, the RF antenna <NUM> may be a non-resonant antenna and the low noise amplifier may be configured with a high input impedance value. Conventionally, a coupling circuit may be configured to resonate at a center frequency, and a decoupling circuit may be configured to maintain a receiving coil in a non-working state when a transmitting coil is emitting signals. Due to the high input impedance of the low noise amplifier, coupling/decoupling circuits between coils of the RF antenna may be removed, and a signal to noise ratio of RF signals may be improved. Also due to the high input impedance of the low noise amplifier, a matching network for matching the input impedance of an RF antenna and the coupling circuit may be omitted.

In some embodiments, the low noise amplifier with a high input impedance value may be configured to receive and output differential signals, avoiding the generation of common-mode signals during signal transmissions. The common-mode signals may cause unwanted coupling and signal-to-noise ratio (SNR) loss. The coils may be the volume coils <NUM>, the local coils <NUM>, the gradient coil <NUM>, or the like, or a combination thereof.

<FIG> is a schematic diagram illustrating an exemplary analog signal processor according to some embodiments of the present disclosure. As shown in <FIG>, the analog signal processor <NUM> may include a low noise amplifier <NUM> and a filter <NUM>.

The analog signal processor <NUM> may be configured to amplify and filter an RF signal received from the RF antenna <NUM>. The low noise amplifier <NUM> may directly sample the RF signal received from the RF antenna <NUM>. The direct sampling architecture may reduce the need of the number of analog devices. The performance of the direct sampling architecture may depend on the processing capacity of the analog-to-digital converter, i.e., a speed and a number of bits of an analog-to-digital converter. The low noise amplifier <NUM> may be a low noise amplifier with a high gain. The filter <NUM> may be configured to filter the amplified RF signal. The filter <NUM> may be a low-pass filter or a bandpass filter.

<FIG> is a schematic diagram illustrating an exemplary analog signal processor according to some embodiments of the present disclosure. As shown in <FIG>, the analog signal processor <NUM> may include a low noise amplifier <NUM>, a down converter <NUM>, a local oscillator <NUM> and a channel selection filter <NUM>.

The analog signal processor <NUM> may be a heterodyne receiver. The heterodyne receiver may convert a received signal (e.g., an amplified RF signal generated by the low noise amplifier <NUM>) to an intermediate frequency. The intermediate frequency may satisfy a frequency requirement of subsequent components.

The low noise amplifier <NUM> may be configured to amplify an RF signal received by an RF antenna. The amplification may be linear or nonlinear. The local oscillator <NUM> may be configured to generate a local oscillation signal to be supplied to the low noise amplifier <NUM>.

The down converter <NUM> may include or may be coupled to a mixer. The mixer may be configured to mix the amplified RF signal and the local oscillation signal. Merely by way of example, the frequency of RF signal may be expressed as fIF and the frequency of the location oscillation signal may be expressed as fLO. The mixer may generate two signals at fLO+ fIF and fLO- fIF, respectively. In some embodiments, the down converter <NUM> may retain and output the signal at fLO- fIF (which is the intermediate frequency). The channel selection filter <NUM> may be configured to filter the output signal of the down converter <NUM>. In some embodiments, an interference signal may occur at 2fIF-fLO (also called an image frequency). The channel selection filter <NUM> may be a bandpass filter to remove the interference signal.

<FIG> is a schematic diagram illustrating an exemplary analog signal processor according to some embodiments of the present disclosure. As shown in <FIG>, the analog signal processor <NUM> may include a low noise amplifier <NUM>, a first down converter <NUM>, a first low-pass filter <NUM>, a second down converter <NUM>, a local oscillator <NUM>, a phase-shifting circuit <NUM>, and a second low-pass filter <NUM>.

The analog signal processor <NUM> may be a homodyne receiver. As used herein, a homodyne receiver may refer to a direct down-converting receiver. The carrier frequency of a homodyne receiver (frequency of RF signal) may be the same as a local frequency (e.g., the frequency of a local oscillation signal generated by the local oscillator <NUM>).

The homodyne receiver may be related to an orthogonal down-conversion. The orthogonal down-conversion may produce an orthogonal signal I and an orthogonal signal Q. The orthogonal signal I and the orthogonal signal Q may have same amplitude but different phase. The orthogonal down-conversion may be realized based on the first down converter <NUM>, the first low-pass filter <NUM>, the second down converter <NUM>, the local oscillator <NUM>, the phase-shifting circuit <NUM>, and the second low-pass filter <NUM>. The low noise amplifier <NUM> and the local oscillator <NUM> may be similar with the low noise amplifier <NUM> and the local oscillator <NUM>, and are not repeated herein. In some embodiments, the local oscillator <NUM> may generate a local oscillation signal at a frequency of the received RF signal. The phase-shifting circuit <NUM> may shift the local oscillation signal by <NUM> degrees (the amplitude and frequency remain unchanged) to generate a phase shifted local oscillation signal.

The first down converter <NUM> may be configured to convert an amplified RF signal (e.g., an RF signal amplified by the low noise amplifier <NUM>) to a zero frequency signal based on a phase shifted local oscillation signal. The method of mixing the phase shifted local oscillation signal and the amplified RF signal is similar to those described in <FIG> and is not repeated herein. An output of the first down converter <NUM> may be input to the first low-pass filter <NUM> to generate the orthogonal signal I.

Similarly, the second down converter <NUM> may be configured to convert an amplified RF signal (e.g., an RF signal amplified by the low noise amplifier <NUM>) to a zero frequency signal based on a local oscillation signal. An output of the second down converter <NUM> may be input to the second low-pass filter <NUM> to generate the orthogonal signal Q.

In some embodiments, the low noise amplifier may be configured with high input impedance. As used herein, the high input impedance may refer to the value of input impedance being greater than <NUM> Ohms, <NUM> Ohms, or <NUM> Ohms. The low noise amplifier with high input impedance may be realized by a field effect transistor (FET), a high electron mobility transistor (HEMT), or the like, or a combination thereof.

<FIG> is a schematic diagram illustrating an exemplary magnetic resonance RF coil according to some embodiments of the present disclosure. As shown, the magnetic resonance RF coil <NUM> may include an RF antenna <NUM> and a digital signal processor <NUM>.

The RF antenna <NUM> may be a loop structure. The digital signal processor <NUM> may include an analog-to-digital sampling circuit. The analog-to-digital sampling circuit may be configured to directly convert an analog signal (e.g., an RF signals received by the RF antenna <NUM>) to a digital signal. In some embodiments, the digital signal processor <NUM> may process the sampled digital signal, the processing including procedures of signal amplification, frequency conversion, filtering, notch. Based on magnetic resonance RF coil <NUM>, analog components may be omitted, and more space of the RF coil <NUM> may be saved, allowing the designing of the RF coil <NUM> to be more diversified.

<FIG> is a schematic diagram illustrating an exemplary magnetic resonance RF coil according to some embodiments of the present disclosure. As shown, the magnetic resonance RF coil <NUM> may include an RF antenna <NUM>, an analog signal processor <NUM> and an analog-to-digital converter <NUM>. The RF antenna <NUM> may be in a birdcage structure. The analog signal processor <NUM> and the analog-to-digital converter <NUM> may be similar to the analog signal processor <NUM> and the analog-to-digital converter <NUM>, respectively, and are not repeated herein.

<FIG> is a schematic diagram illustrating an exemplary magnetic resonance RF coil <NUM> according to some embodiments of the present disclosure. As shown, the magnetic resonance RF coil <NUM> may include a magnetic resonance RF coil <NUM> and a signal processor <NUM>.

The magnetic resonance RF coil <NUM> may be configured to receive RF signals. The RF signals may be emitted by the imaging object <NUM>. In some embodiments, the magnetic resonance RF coil <NUM> may be an RF volume coil. The RF volume coil may be in a structure of a birdcage. The RF volume coil may be placed inside the gantry <NUM> of the MRI scanner and encompass the entire body of the imaging object <NUM>. In some embodiments, the magnetic resonance RF coil <NUM> may be a local coil. The local coil may be configured to encompass a portion of the body of the imaging object <NUM>, for example, a head, a wrist, a shoulder, a spine, a foot, or the like, or a combination thereof. The magnetic resonance RF coil <NUM> may be made of one or more deformable materials. For example, the magnetic resonance RF coil <NUM> may be made of shape-memory alloy. The shape-memory alloy may recover to its original shape under a recovering condition (e.g., a high temperature, a large strain). The shape-memory alloy may include silver, cadmium, gold, nickel, titanium, hafnium, copper, zinc, or the like, or any combination thereof. For another example, the magnetic resonance RF coil <NUM> may be made of deformable conductive materials. The deformable conductive materials may include metallic materials such as solid metals, alloys, liquid metals, etc. The liquid metals may include mercury, aluminum, cesium, gallium, rubidium, or the like, or any combination thereof. In some embodiments, the magnetic resonance RF coil <NUM> may be a single-channel coil, for example, a coil with one loop. In some embodiments, the magnetic resonance RF coil <NUM> may be a coil array with a plurality channels. The number of channels may be <NUM>, <NUM>, <NUM>, <NUM>, etc..

The signal processor <NUM> may be configured to process the RF signals received by the magnetic resonance RF coil <NUM>. The processing may include procedures of analog signal amplification, filtering, notch, frequency conversion, analog-to-digital conversion, or the like, or a combination thereof.

The signal processor <NUM> may include a matching circuit <NUM>, an amplifier <NUM> and an analog-to-digital converter <NUM>. The matching circuit <NUM> may be coupled to the magnetic resonance RF coil <NUM> and the amplifier <NUM>. The matching circuit <NUM> may be configured to match impedance of the magnetic resonance RF coil <NUM> and impedance of the amplifier <NUM>. The amplifier <NUM> may be configured to amplify the signal received by the magnetic resonance RF coil <NUM>. The analog-to-digital converter <NUM> may be similar to the analog-to-digital converter <NUM>, and is not repeated herein.

<FIG> is a schematic diagram illustrating an exemplary amplifying circuit according to some embodiments of the present disclosure. As shown, the amplifying circuit <NUM> may include an amplifier <NUM>, a first adjusting circuit <NUM>, a second adjusting circuit <NUM>, a bias circuit <NUM>, and a third adjusting circuit <NUM>. The amplifying circuit <NUM> (or the amplifier <NUM>) may correspond to the amplifier described elsewhere in the present disclosure (e.g., low noise amplifier <NUM>, low noise amplifier <NUM>, low noise amplifier <NUM>, amplifier <NUM>).

The amplifier <NUM> may be configured to amplify an RF signal. The amplifier <NUM> may include a first port A, a second port B, a third port C, and a fourth port D. The first port A may be an input port of the amplifier <NUM>. The third port C may be an output port of the amplifier <NUM>. The second port B and the fourth port D may be bypass ports of the amplifier <NUM>. The bypass ports may be configured to distribute power or bias a circuit.

The first adjusting circuit <NUM> may be configured to receive an RF signal (e.g., an RF signal received by an RF coil). The first adjusting circuit <NUM> may be electrically coupled to an input port of the amplifying circuit <NUM> (e.g., the first port A). The first adjusting circuit <NUM> may be configured to adjust a value of an input impedance of the amplifier <NUM>. For example, the first adjusting circuit <NUM> may be configured to adjust the value of the input impedance of the amplifier <NUM> to a real value (e.g., remove the imaginary part of the impedance of the amplifier <NUM>). The first adjusting circuit <NUM> may include adjustable components. For example, the first adjusting circuit <NUM> may include a first resistor R1, a first capacitor C1, and a second capacitor C2. The first capacitor C1 and the second capacitor C2 may be variable capacitors. The capacitance of a variable capacitor may be mechanically controlled or electronically controlled. A mechanically controlled capacitor may include a vacuum variable capacitor, a butterfly capacitor, a split stator variable capacitor, a differential variable capacitor, or the like, or a combination thereof. An electrically controlled capacitor may include a voltage tuned variable capacitor, an integrated circuit (IC) variable capacitor, or the like, or a combination thereof.

Similar to the first adjusting circuit <NUM>, the second adjusting circuit <NUM> may also be electrically connected to an input port A of the amplifier <NUM>. The second adjusting circuit <NUM> may include adjustable components. For example, the second adjusting circuit <NUM> may include a second resistor R2 and a third capacitor C3 and the third capacitor C3 may be a variable capacitor. The second adjusting circuit <NUM> may also be configured to adjust the value of the input impedance of the amplifier <NUM> to a real value.

The bias circuit <NUM> may be configured to distribute power. The bias circuit <NUM> may be electrically connected to a bypass port of the amplifier <NUM> (e.g., the fourth port D). The bias circuit <NUM> may include a third resistor R3 and a fifth capacitor R5.

The third adjusting circuit <NUM> may be configured to receive an amplified RF signal from the amplifier <NUM>. The third adjusting circuit <NUM> may be electrically connected to a bypass port of the amplifier <NUM> (e.g., the fourth port D). The third adjusting circuit <NUM> may be configured to adjust a value of an output impedance of the amplifier <NUM>. For example, the third adjusting circuit <NUM> may be configured to adjust the value of the output impedance of the amplifier <NUM> to a real value. The third adjusting circuit <NUM> may include adjustable components. For example, the third adjusting circuit <NUM> may include a fourth resistor R4, a fifth resistor R5 and a sixth capacitor C6. The sixth capacitor C6 may be a variable capacitor.

In some embodiments, the input impedance of the amplifier <NUM> may be determined based on the first adjusting circuit <NUM> and the second adjusting circuit <NUM>. The input impedance of the amplifier <NUM> may be determined by the impedance of the first adjusting circuit <NUM> and the second adjusting circuit <NUM> according to a double terminal network described in <FIG>. The value of the input impedance of the amplifier <NUM> may be expressed in the form of a first complex number. The magnitude of the imaginary part of the first complex number may be set to <NUM> by adjusting capacitances of the first capacitor C1, the second capacitor C2, and/or the third capacitor C3.

In some embodiments, the output impedance of the amplifier <NUM> may be determined based on the third adjusting circuit <NUM>. The output impedance of the amplifier <NUM> may be determined by impedance of the third adjusting circuit <NUM> according to the double terminal network described in <FIG>. The value of the output impedance of the amplifier <NUM> may be expressed in the form of a second complex number. The magnitude of the imaginary part of the second complex number may be set to <NUM> by adjusting the capacitance of the sixth capacitor C6.

This description is intended to be illustrative, and not to limit the scope of the present disclosure. Many alternatives, modifications, and variations will be apparent to those skilled in the art. The features, structures, methods, and other characteristics of the exemplary embodiments described herein may be combined in various ways to obtain additional and/or alternative exemplary embodiments. For example, the adjustable component configured to adjust the input impedance and the output impedance of the amplifier <NUM> may also be a variable inductor, or a combination of a variable capacitor and a variable inductor. As another example, the pulse controller <NUM>, the processing engine <NUM>, and/or the display <NUM> may be integrated into an MRI console (not shown). Users may set parameters in MRI scanning, control the imaging procedure, and view the images produced through the MRI console. However, those variations and modifications do not depart the scope of the present disclosure.

<FIG> is a schematic diagram illustrating an exemplary double terminal network according to some embodiments of the present disclosure. As shown in <FIG>, the double terminal network <NUM> may include an input <NUM> and an output <NUM>.

Merely by way of example, the input <NUM> and the output <NUM> may be expressed as: <MAT> where V<NUM> may denote the voltage of the input <NUM>, V<NUM> may denote the voltage of the output <NUM>, I<NUM> may denote the current of the input <NUM>, I<NUM> may denote the current of the output <NUM>, and z<NUM>, z<NUM>, z<NUM> and z<NUM> may denote impedances between the input <NUM> and the output <NUM>.

Merely by way of example, the impedances between the input <NUM> and the output <NUM> may be determined by: <MAT> <MAT> <MAT> <MAT>.

By measuring the voltage and current of the amplifier, the input impedance and the output impedance of the amplifier may be calculated as complex values according to the formulae (<NUM>) to (<NUM>). The variable components (e.g., C1, C2, C3, C6, etc.) in the amplifying circuit <NUM> may then be adjusted to remove the imaginary part of the complex impedances.

This description is intended to be illustrative, and not to limit the scope of the present disclosure. Many alternatives, modifications, and variations will be apparent to those skilled in the art. The features, structures, methods, and other characteristics of the exemplary embodiments described herein may be combined in various ways to obtain additional and/or alternative exemplary embodiments. For example, three or more groups of pixels may be connected to a same signal transmission board. However, those variations and modifications do not depart the scope of the present disclosure.

It should be noted that the above description of the embodiments are provided for the purposes of comprehending the present disclosure, and not intended to limit the scope of the present disclosure. For persons having ordinary skills in the art, various variations and modifications may be conducted in the light of the present disclosure. However, those variations and the modifications do not depart from the scope of the present disclosure.

Having thus described the basic concepts, it may be rather apparent to those skilled in the art after reading this detailed disclosure that the foregoing detailed disclosure is intended to be presented by way of example only and is not limiting. Various alterations, improvements, and modifications may occur and are intended to those skilled in the art, though not expressly stated herein. These alterations, improvements, and modifications are intended to be suggested by this disclosure, and are within the scope of the exemplary embodiments of this disclosure.

Accordingly, aspects of the present disclosure may be implemented entirely hardware, entirely software (including firmware, resident software, micro-code, etc.) or combining software and hardware implementation that may all generally be referred to herein as a "block," "module," "engine," "unit," "component," or "system.

A computer readable signal medium may include a propagated data signal with computer readable program code embodied therein, for example, in baseband or as part of a frame wave.

Computer program code for carrying out operations for aspects of the present disclosure may be written in any combination of one or more programming languages, including an object-oriented programming language such as Java, Scala, Smalltalk, Eiffel, JADE, Emerald, C++, C#, VB.

Furthermore, the recited order of processing elements or sequences, or the use of numbers, letters, or other designations therefore, is not intended to limit the claimed processes and methods to any order except as may be specified in the claims. Although the above disclosure discusses through various examples what is currently considered to be a variety of useful embodiments of the disclosure, it is to be understood that such detail is solely for that purpose, and that the appended claims are not limited to the disclosed embodiments, but, on the contrary, are intended to cover modifications and equivalent arrangements that are within the scope of the disclosed embodiments. For example, although the implementation of various components described above may be embodied in a hardware device, it may also be implemented as a software only solution-e.g., an installation on an existing server or mobile device.

Similarly, it should be appreciated that in the foregoing description of embodiments of the present disclosure, various features are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure aiding in the understanding of one or more of the various inventive embodiments. This method of disclosure, however, is not to be interpreted as reflecting an intention that the claimed object matter requires more features than are expressly recited in each claim.

In some embodiments, the numbers expressing quantities of ingredients, properties, and so forth, used to describe and claim certain embodiments of the application are to be understood as being modified in some instances by the term "about," "approximate," or "substantially. " For example, "about," "approximate," or "substantially" may indicate ±<NUM>% variation of the value it describes, unless otherwise stated. Accordingly, in some embodiments, the numerical parameters set forth in the written description and attached claims are approximations that may vary depending upon the desired properties sought to be obtained by a particular embodiment. In some embodiments, the numerical parameters should be construed in light of the number of reported significant digits and by applying ordinary rounding techniques. Notwithstanding that the numerical ranges and parameters setting forth the broad scope of some embodiments of the application are approximations, the numerical values set forth in the specific examples are reported as precisely as practicable.

It is to be understood that the embodiments of the application disclosed herein are illustrative of the principles of the embodiments of the application. Other modifications that may be employed may be within the scope of the application. Thus, by way of example, but not of limitation, alternative configurations of the embodiments of the application may be utilized in accordance with the teachings herein. Accordingly, embodiments of the present application are not limited to that precisely as shown and described.

Claim 1:
A magnetic resonance coil (<NUM>), comprising:
a radio frequency (RF) antenna (<NUM>) configured to receive an RF signal emitted from an object, wherein the RF antenna (<NUM>) is a non-resonant antenna; and
a signal processor (<NUM>) coupled to the RF antenna (<NUM>) and configured to process the RF signal to generate a processed signal, the signal processor (<NUM>) comprising an amplifying circuit (<NUM>), wherein the amplifying circuit (<NUM>) comprises:
an amplifier (<NUM>) configured to amplify the RF signal, wherein an input impedance of the amplifier (<NUM>) is greater than <NUM> Ohms,
the amplifier including a first port (A), a second port (B), a third port (C), and a fourth port (D), wherein the first port (A) is an input port, the second port (B) and the fourth port (D) are bypass ports configured to distribute power or bias a circuit, and the third port (C) is an output port;
the amplifying circuit including a first adjusting circuit (<NUM>), a second adjusting circuit (<NUM>), a bias circuit (<NUM>), and a third adjusting circuit (<NUM>), wherein:
the bias circuit (<NUM>) is electrically connected to a bypass port of the amplifier and configured to distribute power, each of the first adjusting circuit (<NUM>) and the second adjusting circuit (<NUM>) is coupled to the input port of the amplifier (<NUM>) and includes at least one first adjustable component, each of the first adjusting circuit (<NUM>) and the second adjusting circuit (<NUM>) being configured to adjust an input impedance of the amplifier (<NUM>) from a first complex value to a first real value via the at least one first adjustable component, and
the third adjusting circuit (<NUM>) is coupled to the fourth port (D) and the output port of the amplifier (<NUM>) and includes at least one second adjustable component, the third adjusting circuit (<NUM>) being configured to adjust an output impedance of the amplifier (<NUM>) from a second complex value to a second real value via the at least one second adjustable component.