摘要:
In a method and computer program product for operating a tomographic imaging apparatus, a standard measurement protocol is generated by displaying a planning representation of a standard object, defining a spatial position of a standard imaging area in the planning representation, and storing, as the standard measurement protocol for the standard object, a reference to the standard object and parameters of the standard imaging area. Such a standard measurement protocol can then be used in the slice position planning for an actual tomographic measurement, by obtaining data representing features of an examination object, corresponding to the standard object, determining a geometrical relation of the features of the examination object to features of the standard object, and generating an object-specific measurement protocol wherein the imaging area is positioned relative to the examination object by modification of the standard measurement protocol.
摘要:
A system and method for performing an MRI or MRS scan that is optimized for a particular target structure. A prescan is conducted during a first session in which an image that is optimized for segmentation is acquired along with an alignment scout image or a 2D or 3D navigator signal. The segmentation process is employed to locate and define the target structure. During a second session the alignment scout image or navigator signal is reacquired and the information is used to determine the position transformation needed to align images from the two sessions. The position transformation information and the segmentation information are then employed to tailor a prescribed pulse sequence to examine the target structure.
摘要:
An fMRI study is conducted using a 2D EPI pulse sequence. A separate blood flow navigator pulse sequence is interleaved with the fMRI data acquisition to monitor blood flow in arteries that feed the brain tissue. Information in the blood flow navigator data is used to reduce errors in the fMRI data due to tissue motion caused by pulsatile blood flow. In one embodiment the blood flow navigator information is used to gate the fMRI acquisition and in another embodiment the information is used to retrospectively correct acquired fMRI data.
摘要:
A system and method for performing an MRI or MRS scan that is optimized for a particular target structure. A prescan is conducted during a first session in which an image that is optimized for segmentation is acquired along with an alignment scout image or a 2D or 3D navigator signal. The segmentation process is employed to locate and define the target structure. During a second session the alignment scout image or navigator signal is reacquired and the information is used to determine the position transformation needed to align images from the two sessions. The position transformation information and the segmentation information are then employed to tailor a prescribed pulse sequence to examine the target structure.
摘要:
Systems and methods for estimating frequency drifts in magnetic resonance signals acquired with a magnetic resonance imaging (“MRI”) system are provided. In one example, the frequency drifts are estimated from phase-correction data that are obtained during an echo-planar imaging (“EPI”), or other multiecho imaging, scan. The systems and methods of the present invention provide for efficiently and accurately computing frequency drift values that can be used for real-time, prospective frequency drift correction.
摘要:
A system and method for producing MR images in which bone and soft tissue are identified. The method includes applying a pulse sequence that includes a first stage configured to acquire a radially-encoded FID and radially-encoded echoes performed after a non-selective RF excitation pulse and before a second stage, which is configured to acquire additional echoes. The radially-encoded MR data acquired during the first stage is substantially representative of bone, while the MR data acquired during the second stage is substantially representative of soft tissues. MR images in which bone and soft tissue are identified are reconstructed from these MR data sets.
摘要:
A system and method for medical imaging includes an improvement to the MP-RAGE pulse sequence that enables the readout bandwidth thereof to be matched to that of other pulse sequences used in the same examination without a significant loss in SNR. More specifically, the present invention includes using a multi-echo MP-RAGE pulse sequence in which multiple gradient-recalled NMR signals are acquired at the desired “matching” bandwidth and combining selected ones of the NMR signals to reconstruct an image. By selecting and combining NMR signals acquired at each phase encoding, the SNR of the resulting reconstructed image can be maintained.
摘要:
A system, method, software arrangement and computer-accessible medium for correcting for a motion of an object are provided. In this system, method, software arrangement and computer-accessible medium, the navigator data and map data can be obtained for the object. Then, the navigator data is compared with the map to generate comparison data. Thereafter, a translation and/or a rotation of the object is corrected in real-time as a function of the comparison data. The navigator can be preferably a clover leaf navigator. In one exemplary embodiment, a scanning sequence can be used to determine a position of the object. For example, this scanning sequence may include a signal portion which includes at least one radio frequency signal, a navigator portion which includes at least one clover leaf navigator, and a spoiler portion provided for reducing a signal magnitude of the scanning sequence. The navigator is provided for allowing a measurement of the rotation and/or the translation of the object. The measurement can be adjusted by correcting for phase encoding effects, shimming errors, and B0 drifts. A feedback control system may be provided to repeatedly correct the measurement of the rotation and translation of the object. The navigator portion can advantageously be provided between the signal portion and the spoiler portion. The system, method, software arrangement and computer-accessible medium may be implemented when multiple coils are present.
摘要:
In a method and computer program product for operating a tomographic imaging apparatus, a standard measurement protocol is generated by displaying a planning representation of a standard object, defining a spatial position of a standard imaging area in the planning representation, and storing, as the standard measurement protocol for the standard object, a reference to the standard object and parameters of the standard imaging area. Such a standard measurement protocol can then be used in the slice position planning for an actual tomographic measurement, by obtaining data representing features of an examination object, corresponding to the standard object, determining a geometrical relation of the features of the examination object to features of the standard object, and generating an object-specific measurement protocol wherein the imaging area is positioned relative to the examination object by modification of the standard measurement protocol.
摘要:
A system and method for producing MR images in which bone and soft tissue are identified. The method includes applying a pulse sequence that includes a first stage configured to acquire a radially-encoded FID and radially-encoded echoes performed after a non-selective RF excitation pulse and before a second stage, which is configured to acquire additional echoes. The radially-encoded MR data acquired during the first stage is substantially representative of bone, while the MR data acquired during the second stage is substantially representative of soft tissues. MR images in which bone and soft tissue are identified are reconstructed from these MR data sets.