Disclosed herein is a medical system (100, 300). The execution of machine executable instructions (120) causes a processor (104) to: receive (200) measured gradient echo k-space data (122); receive (202) an off-resonance phase map (124); reconstruct (204) an initial image (126) from the measured gradient echo k-space data; calculate (206) an upsampled phase map (128) from the off-resonance phase map; calculate (208) an upsampled image (130) from the initial image; calculating (210) a modulated image (132) by modulating the upsampled image with the upsampled phase map; calculate (212) a corrected image (134) comprising iteratively. The iterative calculation comprises: calculating (214) updated k-space data by applying a data consistency algorithm (138) to a k-space representation of the modulated image and the measured gradient echo k-space data and calculating (216) an updated image (142) from the updated k-space data. Calculation of the updated image comprises demodulation by the upsampled phase map and applying a smoothing algorithm.

Deoxyhemoglobin in a subject may be modulated to act as a contrast agent for use in magnetic resonance imaging. Sequential gas delivery may be applied to adjust the level of deoxyhemoglobin in the subject. A suitable magnetic resonance imaging (MRI) pulse sequence that is sensitive to magnetic field inhomogeneities, such as a blood-oxygen-level dependent (BOLD) sequence, may be used to detect deoxyhemoglobin as a contrast agent.

Deoxyhemoglobin in a subject may be modulated to act as a contrast agent for use in magnetic resonance imaging. Sequential gas delivery may be applied to adjust the level of deoxyhemoglobin in the subject. A suitable magnetic resonance imaging (MRI) pulse sequence that is sensitive to magnetic field inhomogeneities, such as a blood-oxygen-level dependent (BOLD) sequence, may be used to detect deoxyhemoglobin as a contrast agent.

A system and a method determine a value for a parameter. Reference values for the parameter are determined from a group of objects. A first technique is used by the system for determining for each object the reference value from a first set of data. A learning dataset is created by associating for each object of the group of objects a second set of data and the reference value. The second set of data is acquired by the system according to a second technique for determining values of the parameter and is configured for enabling a determination of the parameter. A machine learning technique trained on the learning dataset is used for determining a value of the parameter. The second set of data obtained for each of the objects is used as input in a machine learning algorithm and its associated reference value is used as output target.

Described herein are methods for removing the vibration induced additional signal obtained during downhole NMR operations. The additional signal is removed by analyzing a number of instances of data sets neighbors, at either the raw echo, reconstructed echoes, or the spectrum which results from inversion. A number of neighboring data instances are analyzed together to find the minimal (lowest) common values in each. Thereafter, the minimal value replaces the previous value across the data instances, thereby removing the extra signal.

Described herein are methods for removing the vibration induced additional signal obtained during downhole NMR operations. The additional signal is removed by analyzing a number of instances of data sets neighbors, at either the raw echo, reconstructed echoes, or the spectrum which results from inversion. A number of neighboring data instances are analyzed together to find the minimal (lowest) common values in each. Thereafter, the minimal value replaces the previous value across the data instances, thereby removing the extra signal.

Disclosed herein is a medical system (400) comprising a magnetic resonance imaging system (402) configured for acquiring magnetic resonance imaging data (444, 444′) from a subject (418) within an imaging zone (408). The medical system further comprises a subject support (100) configured for supporting at least a portion of the subject within the imaging zone, wherein the subject support comprises a radiotherapy couch top (102) 5 configured for receiving the subject. The radiotherapy couch top comprises a flat surface (104) configured for supporting the subject. The radiotherapy couch top further comprises a head support region (110) configured for receiving a head of the subject, wherein the head region comprises a depression (108). The head region is configured for receiving a flat head support plate (112). The medical system further comprises a flat head support plate. The flat head support plate is configured to form part of the flat surface (104′) when installed in the head region.

Disclosed herein is a medical system (400) comprising a magnetic resonance imaging system (402) configured for acquiring magnetic resonance imaging data (444, 444′) from a subject (418) within an imaging zone (408). The medical system further comprises a subject support (100) configured for supporting at least a portion of the subject within the imaging zone, wherein the subject support comprises a radiotherapy couch top (102) 5 configured for receiving the subject. The radiotherapy couch top comprises a flat surface (104) configured for supporting the subject. The radiotherapy couch top further comprises a head support region (110) configured for receiving a head of the subject, wherein the head region comprises a depression (108). The head region is configured for receiving a flat head support plate (112). The medical system further comprises a flat head support plate. The flat head support plate is configured to form part of the flat surface (104′) when installed in the head region.

A system and method are provided for magnetic resonance imaging (MRI) and/or image reconstruction that includes acquiring multi-pass, chemical shift-encoded (CSE)-MRI imaging data of a subject. The method further includes performing a complex, joint estimation of phase terms in the imaging data for each pass of the multi-pass, CSE-MRI imaging data to account for concomitant gradient (CG)-induced phase errors of different passes. The method also includes generating at least one of a proton density fat fraction (PDFF) estimate or an R*2 estimate that is unbiased by CG-induced phase errors using the phase terms and communicating a report that includes at least one of the PDFF estimate or the R*2 estimate.

A method for multi-dimensional, relaxation-diffusion magnetic resonance fingerprinting (MRF) includes performing, using a magnetic resonance imaging (MRI) system, a pulse sequence that integrates free-waveform b-tensor diffusion encoding into a magnet resonance fingerprinting pulse sequence to perform a multi-dimensional, relaxation-diffusion encoding while acquiring MRF signal evolutions, processing, using a processor, the acquired MRF signal evolutions to determine at least one relaxation parameter and at least one diffusivity parameter, and generating, using the processor, a report including at least one of the at least one relaxation parameter and the at least diffusivity parameter.