摘要:
A magnetic resonance apparatus (10) includes a magnet (18) that generates a static magnetic field, e.g., 7T, a resonance excitation system (26, 30, 32) induces resonance in an observed nuclear species such as 13C or 31P. A decoupling delay generator (48) introduces pauses between adjacent pulses of a decoupling pulse train configured to decouple a coupled species such as 1H. An RF amplifier (32, 44) whose energy shortage capacity would be exceeded by the pulse train without the pauses amplifies the pulse train with the pauses. The pauses are sufficiently short that decoupling and Nuclear Overhauser Effect enhancement are not adversely affected, but long enough to provide recovery time to the RF amplifier, e.g., 0.2 msec.
摘要:
A magnetic resonance apparatus includes a magnet that generates a static magnetic field, e.g., 7T, and a resonance excitation system that induces resonance in an observed nuclear species such as 13C or 31P. A decoupling delay generator introduces pauses between adjacent pulses of a decoupling pulse train configured to decouple a coupled species such as 1H. An RF amplifier whose energy shortage capacity would be exceeded by the pulse train without the pauses amplifies the pulse train with the pauses. The pauses are sufficiently short that decoupling and Nuclear Overhauser Effect enhancement are not adversely affected, but long enough to provide recovery time to the RF amplifier, e.g., 0.2 msec.
摘要:
In a magnetic resonance imaging data acquisition method, k-space (100) is divided into a central region (102) disposed at k-space center and one or more annular surrounding regions (104, 106) having increasing distances from k-space center. The one or more annular surrounding regions include an outermost surrounding region (106) having a largest distance from k-space center. The k-space samples in the central region (102) are acquired. Subsequent to the acquiring of k-space samples in the central region, k-space samples are acquired in the one or more annular surrounding regions (104, 106). The k-space samples in the outermost surrounding region (106) are acquired last. The acquiring of k-space samples in at least the outermost surrounding region uses a row-by-row acquisition ordering in which each row of k-space samples acquired in the outermost surrounding region (106) completes a k-space plane.
摘要:
A magnetic resonance imaging method includes acquiring a baseline magnetic resonance image of a region of interest in the absence of a contrast agent and simulating an increase in image intensity of a subregion of interest within the region of interest which is subject to increased image intensity in the presence of a contrast agent. The magnetic resonance k-space signal intensity is correlated with contrast agent concentration in the subregion and a contrast agent is administered to the subject. As k-space data for the region of interest is acquired, the signal intensity is monitored to derive contrast agent concentration information. When the peak contrast agent concentration is detected from the monitored k-space data signal intensity, the phase encoding is adjusted so that k-space data with zero phase encoding is acquired. In a further aspect, a magnetic resonance imaging apparatus is also provided.