MR imaging method and MRI system
First Claim
1. An MR imaging method for constructing a tomographic image of an object using MR signals induced by the object, comprising the steps of:
- acquiring echoes from the object by implementing a pulse sequence, which specifies the conditions that TR=TIP×
m and TE=TIP×
(m−
1±
1/n) should be established with spins excited in the steady-state free precession (SSFP) method, where TR denotes a repetition time, TIP denotes an in-phase time, TE denotes an echo time of a positive value, m denotes a natural number, and n denotes a natural number equal to or larger than 3, so that the object can be scanned with an echo induced by water contained in the object and an echo induced by fat contained therein in single quadrature with each other or with a phase difference of 90°
between the echoes induced by water and fat;
constructing a tomographic image by performing frequency transformation on the acquired echoes;
compensating the transformed data for the inhomogeneity in a static magnetic field; and
reconstructing an image, of which water and fat components are separated from each other, according to the result of the compensation.
2 Assignments
0 Petitions
Accused Products
Abstract
An MR imaging includes acquiring echoes from the object by implementing a pulse sequence which specifies the conditions which should be established with spins excited in the steady-state free precession (SSFP) method, so that the object can be scanned with an echo induced by water contained in the object and an echo induced by fat contained therein in single quadrature with each other or with a phase difference of 90° between the echoes induced by water and fat, constructing a tomographic image by performing frequency transformation on the acquired echoes, compensating the transformed data for the inhomogeneity in a static magnetic field and reconstructing an image, of which water and fat components are separated from each other, according to the result of the compensation.
30 Citations
18 Claims
-
1. An MR imaging method for constructing a tomographic image of an object using MR signals induced by the object, comprising the steps of:
-
acquiring echoes from the object by implementing a pulse sequence, which specifies the conditions that TR=TIP×
m and TE=TIP×
(m−
1±
1/n) should be established with spins excited in the steady-state free precession (SSFP) method, where TR denotes a repetition time, TIP denotes an in-phase time, TE denotes an echo time of a positive value, m denotes a natural number, and n denotes a natural number equal to or larger than 3, so that the object can be scanned with an echo induced by water contained in the object and an echo induced by fat contained therein in single quadrature with each other or with a phase difference of 90°
between the echoes induced by water and fat;
constructing a tomographic image by performing frequency transformation on the acquired echoes;
compensating the transformed data for the inhomogeneity in a static magnetic field; and
reconstructing an image, of which water and fat components are separated from each other, according to the result of the compensation. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
-
-
10. An MRI system for constructing a tomographic image of an object using MR signals induced by said object, comprising:
-
a device for implementing a pulse sequence, which specifies the conditions that TR=TIP×
m and TE=TIP×
(m−
1±
1/n) should be established with spins excited in the steady-state free precession (SSFP) method, where TP denotes a repetition time, TIP denotes an in-phase time, TE denotes an echo time of a positive value, m denotes a natural number, and n denotes a natural number equal to or larger than 3, so that the object can be scanned with an echo induced by water contained in the object and an echo induced by fat contained therein in single quadrature with each other or with a phase difference of 90°
between the echoes induced by water and fat;
a device for acquiring echoes from said object by implementing said pulse sequence;
a transformation device for constructing a tomographic image by performing frequency transformation on the acquired echoes;
a device for compensating the transformed data for the inhomogeneity in a static magnetic field; and
a device for reconstructing an image, of which water and fat components are separated from each other, according to the result of the compensation. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17, 18)
-
Specification