System And Method For Non-Contrast Agent MR Angiography
First Claim
Patent Images
1. A method for producing an angiogram with a magnetic resonance imaging (MRI) system, the method comprising the steps of:
- a) performing a preparatory pulse sequence that includes application of an RF pulse that reduces longitudinal magnetization of spins in a region of interest;
b) performing an image acquisition pulse sequence following a time interval (TI) after step a) to acquire complex image data in which the NMR signals from blood is suppressed, the NMR signals from fat are substantially recovered, and the NMR signals from other tissues are reduced;
c) repeating the image acquisition pulse sequence following step b) to acquire complex image data in which the NMR signals from blood is recovered, the NMR signals from fat are substantially recovered, and the NMR signals from other tissues are reduced;
d) repeating steps a), b), and c) to form a first complex image data set from the complex image data acquired in step b) and a second complex image data set from the complex image data acquired in step c); and
e) performing a subtraction of the first and second image data sets to produce an angiogram in which blood vessels have an enhanced brightness.
2 Assignments
0 Petitions
Accused Products
Abstract
A system and method for imaging a desired region of the circulatory system uses the subtraction of data from two acquisitions using substantially different RF pulses and/or pulse sequence timing parameters. In one or both data sets, the longitudinal magnetization of spins within a selected imaging volume has been altered by the application of one or more RF preparatory (prep) pulses. The prep is applied in such a way that subtraction eliminates signals from static background spins, such as fat, while maintaining the signal intensity of intravascular spins.
64 Citations
10 Claims
-
1. A method for producing an angiogram with a magnetic resonance imaging (MRI) system, the method comprising the steps of:
-
a) performing a preparatory pulse sequence that includes application of an RF pulse that reduces longitudinal magnetization of spins in a region of interest; b) performing an image acquisition pulse sequence following a time interval (TI) after step a) to acquire complex image data in which the NMR signals from blood is suppressed, the NMR signals from fat are substantially recovered, and the NMR signals from other tissues are reduced; c) repeating the image acquisition pulse sequence following step b) to acquire complex image data in which the NMR signals from blood is recovered, the NMR signals from fat are substantially recovered, and the NMR signals from other tissues are reduced; d) repeating steps a), b), and c) to form a first complex image data set from the complex image data acquired in step b) and a second complex image data set from the complex image data acquired in step c); and e) performing a subtraction of the first and second image data sets to produce an angiogram in which blood vessels have an enhanced brightness. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
-
Specification