The present invention relates to the field of medical imaging in the absence of contrast agents. In one form, the invention relates to the field of imaging vessels, particularly blood vessels such as the pulmonary vasculature and is suitable for use as a technique for detecting pulmonary embolism (PE), such as acute PE. Embodiments of the present invention provide improved image processing techniques having the capability to extract and use image data to overcome the need for contrast agents to distinguish between different types of tissue. Furthermore, it has also been realised that the image data accessed by the improved image processing can be used to identify irregularities in vessels.

A subject information acquisition apparatus, comprises: a signal generation unit configured to generate a high-frequency signal corresponding to each of the frequencies; an acquisition unit configured to acquire a plurality of detection signals based on at least one of a reflection signal and a transmission signal; a signal selection unit configured to select at least one detection signal from the plurality of detection signals based on an index value of the plurality of detection signals; a coupling amount detecting unit configured to detect a coupling amount of near-field coupling due to an electric field between the antenna and the subject based on a detection signal; and a displacement detecting unit configured to generate a displacement signal indicating a displacement of the subject based on the coupling amount.

A sensor for motion or gesture sensing may be configured to emit radio frequency signals such as for pulsed range gated sensing. The sensor may include a radio frequency transmitter configured to emit the pulses and a receiver configured to receive reflected ones of the emitted radio frequency signals. The received pulses may be processed by a motion channel and/or a gesture channel. The gesture channel may produce signals for further processing for identification of one or more different motion gestures such as by calculating and evaluating features from any of the amplitude, phase and frequency of the output signals of the gesture channel. The sensing apparatus may optionally serve as a monitor for evaluating user activities, such as by counting activities. The sensor may optionally serve as a user control interface for many different devices by generating control signal(s) based on identification of one or more different motion gestures.

A sensor for motion or gesture sensing may be configured to emit radio frequency signals such as for pulsed range gated sensing. The sensor may include a radio frequency transmitter configured to emit the pulses and a receiver configured to receive reflected ones of the emitted radio frequency signals. The received pulses may be processed by a motion channel and/or a gesture channel. The gesture channel may produce signals for further processing for identification of one or more different motion gestures such as by calculating and evaluating features from any of the amplitude, phase and frequency of the output signals of the gesture channel. The sensing apparatus may optionally serve as a monitor for evaluating user activities, such as by counting activities. The sensor may optionally serve as a user control interface for many different devices by generating control signal(s) based on identification of one or more different motion gestures.

A control device establishes a change in a main magnetic field expected for a respective time instant and based on the established expected change in the main magnetic field, correctively adjusts the main magnetic field and/or a nominal receive frequency of the RF receive coil and/or a transmit frequency for subsequent RF transmit pulses and/or takes the expected change in the main magnetic field into account in the evaluation of the received MR signals. At least for some of the RF transmit pulses, the control device acquires, via a sensor device, a portion of the respective radiofrequency wave supplied to the RF transmit coil. The controller extracts therefrom an oscillation corresponding to a respiratory motion of the patient and based on the variation with time of the extracted oscillation, establishes the change in the main magnetic field expected for the respective time instant.

A control device establishes a change in a main magnetic field expected for a respective time instant and based on the established expected change in the main magnetic field, correctively adjusts the main magnetic field and/or a nominal receive frequency of the RF receive coil and/or a transmit frequency for subsequent RF transmit pulses and/or takes the expected change in the main magnetic field into account in the evaluation of the received MR signals. At least for some of the RF transmit pulses, the control device acquires, via a sensor device, a portion of the respective radiofrequency wave supplied to the RF transmit coil. The controller extracts therefrom an oscillation corresponding to a respiratory motion of the patient and based on the variation with time of the extracted oscillation, establishes the change in the main magnetic field expected for the respective time instant.

A base for supporting a piezoelectric sensor which includes a generally planar support frame having an opening and a housing mounted in the opening. The housing has an upper portion including a sensor and a lower portion including a biasing member in contact with the sensor. The sensor is biased by the biasing force of the biasing member against the upper portion of the housing, whereby the upper portion is in turn biased by the biasing force against a floor of a cage positioned on the upper side of the support frame.

A base for supporting a piezoelectric sensor which includes a generally planar support frame having an opening and a housing mounted in the opening. The housing has an upper portion including a sensor and a lower portion including a biasing member in contact with the sensor. The sensor is biased by the biasing force of the biasing member against the upper portion of the housing, whereby the upper portion is in turn biased by the biasing force against a floor of a cage positioned on the upper side of the support frame.

A method for proton resonance frequency shift (PRF) and T.sub.1-based temperature mapping using a magnetic resonance imaging (MRI) system includes acquiring, using the MRI system, a set of magnetic resonance (MR) data from a region of interest of a subject by performing a variable-flip-angle multi-echo gradient-echo 3D stack-of-radial pulse sequence. The pulse sequence is configured to acquire radial k-space data in a plurality of segments, each segment acquired with each of a plurality of flip angles. The method further includes generating at least one T.sub.1 map based on the set of MR data, generating at least one PRF temperature map based on the set of MR data, generating at least one T.sub.1-based temperature map based on the set of MR data and displaying the PRF temperature map and the T.sub.1-based temperature map. In another embodiment, the MR data may be used to generate a plurality of quantitative parameter maps for each of the plurality of MR parameters such as T.sub.1, proton-density fat fraction (PDFF), and R.sub.2*.

Systems and methods for accurate determination of the position of an anatomic part of a subject in robotic assisted image-based surgery, using an inertial measurement unit (IMU) to determine the position and orientation of the anatomical part of the subject. The intrinsic drift of the IMU, which would make the IMU position measurements inaccurate, can be reset to zero regularly, at points of time when the subject's body is stationary. This can be achieved when motion from the subject's breathing and from the heartbeat are essentially zero. Such positions occur respectively when the respiratory signal shows the position of the breathing cycle to be at the end of the expiration phase, and the heartbeat signal represents a time in the diastole period of the subject's electrocardiographic cycle. When these two signal moments coincide, the IMU is essentially stationary, and its drift reset to zero.