Koninklijke Philips Corporation N.v.

U.S. Philips Corporation

Koninlijke Philips Electronics N.v.

Filips Van Liere

Marc Paul Saes

Sotir Filipov Ouzounov

Marinus Johannes Adrianus Maria Van Helvoort

Miha Fuderer

Cornelis Leonardus Gerardus Ham

Johannes Den Boef

Lambertus De Vries

Dirk Jan Broer

Ralph Kurt

Johan Samuel Van Den Brink

Arne Reykowski

Emiel Peeters

Roel Penterman

Peter Van Der Meulen

Paul Franz Redder

Michel Paul Barbara Van Bruggen

Rameswor Shrestha

Emil Dimitrov Totev

Henricus Gerardus Roeven

Marinus J A M Van Helvoort

Hans Van Zon

Guillaume Rudolf Petrus Thelissen

Johannes Hendrik Den Boef

Marcellus Hendricus Marinus Waltherus Melters

Pol Ketan Jayant

Jacques Den Boer

Cumhur Erdin

A magnetic resonance examination method comprises acquisition of a set of magnetic resonance signals from magnetic spins in an object by way of a receiver antenna, the magnetic resonance signals' signal levels are related to an independent reference level that is independent of the receiver antenna's sensitivity to form a calibrated signal level of the magnetic resonance signals, the calibrated signal levels are recorded in terms of a relative density of ordered transverse spins (DOTS). The independent reference level may be derived from the signal-to-thermal-noise ratio. The calibrated signal level in terms of DOTS in μM/T reflects predominantly a tissue property (of (a voxel of) the patient to be examined) as well as details or characteristics of the acquisition sequence used.

Magnetic resonance examination method

The invention relates to phase-coherent read-out of sensor nodes () of a magnetic resonance imaging system () with a digital serial communication network (). According to the invention, the network () comprises multiple sensor nodes () for detecting a radio frequency signal from a patient who is under examination by the magnetic resonance imaging system (), and a host node () which is connected to the sensor nodes () via a network link () for merging and processing digital sensor data received from the sensor nodes (), wherein the host node () comprises a receiver () connected to the network link () for receiving data over the network link (), and a transmitter () connected to the network link () for transmitting data over the network link (), the sensor nodes () each comprise an analog-to-digital converter () for converting the detected radio frequency signal to the digital sensor data, a receiver () connected to the network link () for receiving data over the network link (), a transmitter () connected to the network link () for transmitting data over the network link (), and a clock and data recovery unit () with a clock device which is configured for miming on a preset free-running frequency, the frequency of the data transmission over the network link () is set to a fixed frequency relative to the preset free-running frequency of the clock devices, and the clock and data recovery units () are configured for generating a recovered clock signal for controlling the analog-to-digital converter () of their sensor node by regulating the frequency of the clock device of their sensor node () to lock to the frequency of the data transmission over the network link (). In this way, the possibility of phase coherent sensory data acquisition with a magnetic resonance imaging system () is provided in a robust and cost-efficient way.

Phase-coherent read-out of MRI sensor nodes

For a radio frequency (RF) receiver system () for providing magnetic resonance (MR) information from an examination space of a MR imaging system, a solution for increasing the dynamic range of the radio frequency (RF) receiver system () for a better imaging performance shall be created. A sigma delta ADC of the RF receiver system operates in single-bit mode with an automatic gain control (AGC) circuit used to control the DAC feedback strength thereby extending the dynamic range of the receiver to match the MRI signal. The present invention also refers to a magnetic resonance (MR) imaging system, a method A method for extending the dynamic range of a radio frequency (RF) receiver system, a software package for a magnetic resonance (MR) imaging system, a software package for upgrading a magnetic resonance (MR) imaging system and a computer program product.

Radio frequency receiver system

Disclosed herein is a medical instrument comprising () a magnetic resonance imaging receive antenna ('). The magnetic resonance imaging receive antenna comprises multiple antenna elements () each configured for receiving a magnetic resonance imaging radio-frequency signal. The magnetic resonance imaging receive antenna further comprises a radio-frequency receiver () connected to each of the multiple antenna elements, wherein the radio-frequency receiver is configured to receive the magnetic resonance imaging radio frequency signal and to convert the radio frequency signal to digital magnetic resonance data (). The magnetic resonance imaging receive antenna further comprises a digital combiner (). The digital combiner is configured to combine a weighted combination of the digital magnetic resonance data from each of the radio frequency signals into a chosen number of digital virtual magnetic resonance channels using a set of weighting factors (). The magnetic resonance imaging receive antenna further comprises a first digital communication transceiver () configured for transmitting the digital virtual magnetic resonance channels via a digital communication channel ().

Magnetic resonance imaging receive antenna

A RF receiver system for an MRI apparatus includes a receive coil, which exhibits a total effective coil impedance composed of the coil impedance of the coil itself and a patient impedance. An analog-to-digital converter is connected to an amplifier for converting the amplified output signal from the amplifier to a digital signal for further processing. A matching network is interconnected between the receive coil and the amplifier and includes a matching system with an adjustable impedance for matching the total effective coil impedance to the lowest noise impedance, and a noise calculation unit is connected to the analog-to-digital converter for receiving the digital output signal of the converter and is configured to calculate noise of the output signal of the analog-to-digital converter and for adjusting the adjustable impedance of the matching network in order to calibrate the matching network for every patient individually before the scanning process.

RF receiver system with adjustable impedance matching

The present invention provides a method for compensation of periodic Bmodulations from a periodic motion of a cold head () of a main magnet () of a magnetic resonance (MR) imaging system (), whereby main windings () of the main magnet () are cooled to superconductivity by the cold head (), which exerts a repetitive motion, the method comprising the steps of measuring a periodic occurrence of spatial field components of the B-field based on a motion of the cold head () as a function of time, performing a sensor measurement of a periodic, auxiliary parameter of the MR imaging system (), which is not the periodic occurrence of spatial field components, synchronizing the periodic occurrence of spatial field components of the B-field with the measured periodic, auxiliary parameter of the MR imaging system (), and triggering based on the measured periodic sensor measurement of the MR imaging system () a periodic application of compensation signals to compensate the periodic occurrence of spatial field components of the B-field based on a motion of the cold head (). Furthermore, the present invention provides a MR imaging system () for providing an image representation of a region of interest () of a subject of interest () positioned in an examination space () of the MR imaging system (), wherein the MR imaging system () is adapted to perform the above method.

Compensation of magnetic field components caused by a periodic motion of a cold head

In MRI system, acquired MR signals that will have a greater impact on the quality of the final reconstructed MRI image if a data link error occurs are encoded with a higher, or more robust, level of encoding prior to being transmitted over a data communications link. Conversely, acquired MR signals that will have a lesser impact on the quality of the final reconstructed MRI image if a data link error occurs are encoded with a lower, or less robust, level of encoding prior to being transmitted over the data communications link. The overall result is improved data link robustness and efficiency for data being sent over the data link.

Method and apparatus for improving data communications link efficiency and robustness in a magnetic resonance imaging (MRI) system

The invention relates to a nuclear magnetic resonance imaging radio frequency-receiver (), the receiver () being adapted to receive analog signals from at least one radio frequency receiver coil unit (), the radio frequency receiver () comprising: an analog-digital converter () to convert the analog pre-amplified magnetic resonance signal into a digital signal, means () for digital down converting the digital signal and a first communication interface () adapted for transmitting the down converted digital signal via a communication link (e.g. wireless, optical or wire-bound).

MRI radio frequency receiver comprising digital down converter with connector that passes analog signal being contained within radio frequency receiver coil unit

A diagnostic imaging system includes a first controller that detects any unsafe or dangerous conditions in a diagnostic scanner and generates safety/emergency data indicative of the unsafe or dangerous conditions. A communication unit generates a safety/emergency signal from the safety/emergency data using a digital protocol and communicates the safety/emergency over a local digital network.

Low latency signaling over digital network

The invention relates to direct digital receiver for an RF coil (), in particular of a magnetic resonance imaging system (), for providing a digital sample output signal at a digital operating frequency in a time base of a system clock (), the receiver comprising: &#x2014;an analogue-to-digital converter () for converting an analogue signal received from the RF coil () to a digital sample input signal, the analogue-to-digital converter () being driven by a local clock, a local clock oscillator () adapted for providing the local clock in a local clock time base to the analogue-to-digital converter (), the local clock time base being independent of the system clock time base, a phase detector () adapted for determining a phase difference () between the system clock () and the local clock, a resampling unit () adapted for resampling the digital sample input signal to the digital sample output signal using said phase difference ().

Direct digital receiver with local free running clock

The invention relates to a RF reception antenna device () for receiving MR signals in a MR imaging system. The device () comprises a RF resonant circuit including a RF reception antenna () for picking up the MR signals, and a RF amplifier () connected at its input to the RF resonant circuit for amplifying the picked up MR signals. The invention proposes to make provision for a detection circuit () configured to derive a switching signal from an output signal of the RF amplifier (). A switching circuit () is responsive to the switching signal, wherein the switching circuit () is configured to switch the RF resonant circuit between a resonant mode and a non-resonant (i.e. detuned) mode.

Detunable RF reception antenna device

A data rate controlling feedback loop evaluates an actual instantaneous available quality of service of a communication link for transmitting data and controls the data rate based on an evaluation result, Feedback control may both be local to a device for acquiring examination data, such as a magnetic resonance imaging coil, or over the communication link by reducing the data rate at least momentarily to fit the communication link's performance over time, enabling a graceful degradation of an image quality at lower data rates.

Adaptive data rate control

The present invention relates to magnetic resonance imaging system and to a direct digital receiver () for an RF coil (D, D), in particular of a magnetic resonance imaging system. To obtain that the sampling frequency of an analog-to-digital converter () of the digital receiver can be chosen independently of the digital operating frequency at which the subsequent digital down converter (), which particularly includes a demodulator (), operates, a resampling unit () is introduced which is coupled between said analog-to-digital converter and said digital down converter for resampling a first digital sample signal at said sampling frequency to a second digital sample signal at said digital operating frequency.

MRI system with direct digital receiver using resampling

A digital receiver circuit includes an encoder () for encoding a digitized magnetic resonance signal is disclosed herein. The digitized magnetic resonance signal includes one or more data packets. Each data packet is representative of a portion of a magnetic resonance signal. The encoder () is configured to dynamically allocate a number of bits for each data packet based on a characteristic of at least the portion of the magnetic resonance signal represented by the particular data packet.

Digitized MR signal data encoding with dynamically variable bit rate

The invention relates to a device () for magnetic resonance imaging of a body () placed in a stationary and substantially homogeneous main magnetic field comprising a main magnet () for generation of a stationary and substantially homogeneous main magnetic field within the examination zone. In order to provide an MR device () which is arranged to allow for massive parallel imaging without extensive cabling between the individual receiving coils and the back end electronics, the invention proposes to make provision for a plurality of receiving units () placed in or near the examination zone, which receiving units () each comprise a receiving antenna () for receiving MR signals from the body, a digitizing means () for sampling the received MR signals and for transforming the signal samples into digital signals, and a transmitter () for transmitting the digital signals to a central processing unit (). Further, the device () comprises synchronization means () for synchronizing the operation of the individual digitizing means () of the receiving units ().

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Eindhoven, Netherlands

Filips Van Liere