# US 8,542,016 B2 · Magnetic resonance imaging apparatus and method > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,542,016 B2 - Document ID: US8542016B2 - Status: Granted - Kind: B2 - Application number: 13/127,833 - Filed: 2009-10-23 - Published: 2011-09-01 - Granted: 2013-09-24 - Earliest claimed: 2008-11-07 - Assignees: Hitachi Medical Corporation - Applicants: Takayuki Abe - Inventors: Takayuki Abe - Web page: https://patentgrep.com/patent/US8542016B2 ## CPC - G01R 33/4828: {Resolving the MR signals of different chemical species, e.g. water-fat imaging} - G01R 33/4835: {of multiple slices} - G01R 33/446: {Multifrequency selective RF pulses, e.g. multinuclear acquisition mode (spatially selective RF pulses G01R33/4833)} - G01R 33/5607: {by reducing the NMR signal of a particular spin species, e.g. of a chemical species for fat suppression, or of a moving spin species for black-blood imaging} - G01R: MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES (indicating correct tuning of resonant circuits H03J3/12) ## Abstract A magnetic resonance imaging apparatus for imaging a plurality of different slice planes having pre-pulse applying means configured to apply a pre-pulse for affecting in-plane magnetization of all slices of a measurement target, measuring means configured to make a measurement for applying one phase encode amount for one slice plane to obtain an echo signal and dispose the echo signal in a k space, and control means configured to control operations of the pre-pulse applying means and the measuring means. The control means has first control means configured to control to repeat an operation of executing the measurement once according to a predetermined order for all slice planes of the measurement target after a first pre-pulse is applied while a phase encode amount is varied in a predetermined order until all k spaces of all slices are filled, and second control means configured to control the pre-pulse applying means so that the pre-pulse is applied every time the measurement is executed at a frequency which is different from the number of the slices of the measurement target and a multiple number of the number of the slices, and the first control means sets an initial phase encode amount of each slice so as to measure a low spatial frequency area of the k space at a timing having a large effect of the pre-pulse. ## Claims ### Claim 1 A magnetic resonance imaging apparatus for imaging a plurality of different slice planes characterized by comprising: pre-pulse applying means configured to apply a pre-pulse for affecting in-plane magnetization of all slices of a measurement target; measuring means configured to make a measurement for applying one phase encode amount for one slice plane to obtain an echo signal and disposing the echo signal in a k space; and control means configured to control operations of the pre-pulse applying means and the measuring means, wherein the control means has first control means configured to control to repeat an operation of executing the measurement once according to a predetermined order for all slice planes of the measurement target after a first pre-pulse is applied while a phase encode amount is varied in a predetermined order until all k spaces of all slices are filled, and second control means configured to control the pre-pulse applying means so that the pre-pulse is applied every time the measurement is executed for the number of times which is different from the number of the slices of the measurement target and a multiple number of the number of the slices, and the first control means sets an initial phase encode amount of each slice so as to measure a low spatial frequency area of the k space at a timing having a large effect of the pre-pulse. ### Claim 2 (depends on 1) The magnetic resonance imaging apparatus according to claim 1, wherein the pre-pulse is a pulse for monotonically reducing the effect, and the first control means divides the k space into segments whose number corresponds to the number of measurement times executed while the pre-pulse applying means applies the pre-pulse, and varies the phase encode amount every measurement on a segment basis in a centric order. ### Claim 3 (depends on 1) The magnetic resonance imaging apparatus according to claim 1, wherein the pre-pulse is a pulse having the maximum effect at a predetermined timing after application thereof, and the first control means divides the k space into segments whose number corresponds to the number of measurement times executed while the pre-pulse applying means applies the pre-pulse, varies the phase encode amount every measurement on a segment basis in a sequential order, and sets an initial phase encode amount so as to obtain data to be disposed in a segment containing the lowest spatial frequency area at a timing having the highest effect of the pre-pulse. ### Claim 4 (depends on 1) The magnetic resonance imaging apparatus according to claim 1, wherein the pre-pulse is a pulse for suppressing an echo signal from hydrogen protons of fat molecules. ### Claim 5 (depends on 1) The magnetic resonance imaging apparatus according to claim 1, wherein the pre-pulse is a pulse for selectively exciting an unnecessary tissue. ### Claim 6 (depends on 1) The magnetic resonance imaging apparatus according to claim 1, wherein the pre-pulse is a T2 preparation pulse. ### Claim 7 (depends on 1) The magnetic resonance imaging apparatus according to claim 1, wherein the pre-pulse is an IR (Inversion Recovery) pulse. ### Claim 8 A magnetic resonance imaging method for imaging a plurality of different slice planes, characterized by comprising: a pre-pulse applying step that applies a pre-pulse for affecting in-plane magnetization of all slices of a measurement target; a measuring step that makes a measurement for applying one phase encode amount for one slice plane to obtain an echo signal and disposes the echo signal in a k space; and a control step that controls operations of the pre-pulse applying means and the measuring means, wherein the control step has a first control step that controls to repeat an operation of executing the measurement once according to a predetermined order for all slice planes of the measurement target after a first pre-pulse is applied while a phase encode amount is varied in a predetermined order until all k spaces of all slices are filled, and a second control step that controls the pre-pulse applying means so that the pre-pulse is applied every time the measurement is executed for the number of times which is different from the number of the slices of the measurement target and a multiple number of the number of the slices, and the first control step sets an initial phase encode amount of each slice so as to measure a low spatial frequency area of the k space at a timing having a large effect of the pre-pulse. ### Claim 9 (depends on 8) The magnetic resonance imaging method according to claim 8, wherein the pre-pulse is a pulse for monotonically reducing the effect, and the first control step divides the k space into segments whose number corresponds to the number of measurement times executed while the pre-pulse applying step applies the pre-pulse, and varies the phase encode amount every measurement on a segment basis in a centric order. ### Claim 10 (depends on 8) The magnetic resonance imaging method according to claim 8, wherein the pre-pulse is a pulse having the maximum effect at a predetermined timing after application thereof, and the first control step divides the k space into segments whose number corresponds to the number of measurement times executed while the pre-pulse applying step applies the pre-pulse, varies the phase encode amount every measurement on a segment basis in a sequential order, and sets an initial phase encode amount so as to obtain data to be disposed in a segment containing the lowest spatial frequency area at a timing having the highest effect of the pre-pulse. ### Claim 11 (depends on 8) The magnetic resonance imaging method according to claim 8, wherein the pre-pulse is a pulse for suppressing an echo signal from hydrogen protons of fat molecules. ### Claim 12 (depends on 8) The magnetic resonance imaging method according to claim 8, wherein the pre-pulse is a pulse for selectively exciting an unnecessary tissue. ### Claim 13 (depends on 8) The magnetic resonance imaging method according to claim 8, wherein the pre-pulse is a T2 preparation pulse. ### Claim 14 (depends on 8) The magnetic resonance imaging method according to claim 8, wherein the pre-pulse is an IR (Inversion Recovery) pulse.