Magnetic resonance imaging with resolution and contrast enhancement

Abstract

MRI scans typically have higher resolution within a slice than between slices. To improve the resolution, two MRI scans are taken in different, preferably orthogonal, directions. The scans are registered by maximizing a correlation between their gradients and then fused to form a high-resolution image. Multiple receiving coils can be used. When the images are multispectral, the number of spectral bands is reduced by transformation of the spectral bands in order of image contrast and using the transformed spectral bands with the highest contrast.

1 - 20 . (canceled)  
     
     
         21 . A method of forming an image of a subject, the method comprising: 
 (a) performing an MRI scan on the subject to take image data having a plurality of spectral bands; and    (b) forming the image from the image data.    
     
     
         22 . The method of  claim 21 , wherein step (b) comprises selecting a subplurality of the plurality of spectral bands to form the image.  
     
     
         23 . The method of  claim 22 , wherein the subplurality of the plurality of spectral bands is selected by ranking the plurality of spectral bands in order of image contrast and selecting the spectral bands whose image contrast is highest.  
     
     
         24 . The method of  claim 23 , wherein the plurality of spectral bands is ranked in order of image contrast by: 
 deriving a covariance matrix from the plurality of spectral bands;    deriving a set of orthogonal eigenvectors and a corresponding set of eigenvalues from the covariance matrix; and    ranking the orthogonal eigenvectors in order of their corresponding eigenvalues.    
     
     
         25 . The method of  claim 21 , wherein step (a) is performed with a plurality of receiving coils.  
     
     
         26 . The method of  claim 25 , wherein step (a) is performed using at least three receiving coils.  
     
     
         27 . The method of  claim 26 , wherein step (a) is performed using at least four receiving coils.  
     
     
         28 - 47 . (canceled)  
     
     
         48 . A system for forming an image of a subject, the system comprising: 
 scanning means for performing an MRI scan on the subject to take image data having a plurality of spectral bands; and    computing means for forming the image from the image data.    
     
     
         49 . The system of  claim 48 , wherein the computing means selects a subplurality of the plurality of spectral bands to form the image.  
     
     
         50 . The system of  claim 49 , wherein the subplurality of the plurality of spectral bands is selected by ranking the plurality of spectral bands in order of image contrast and selecting the spectral bands whose image contrast is highest.  
     
     
         51 . The system of  claim 50 , wherein the plurality of spectral bands is ranked in order of image contrast by: 
 deriving a covariance matrix from the plurality of spectral bands;    deriving a set of orthogonal eigenvectors and a corresponding set of eigenvalues from the covariance matrix; and    ranking the orthogonal eigenvectors in order of their corresponding eigenvalues.    
     
     
         52 . The system of  claim 48 , wherein the scanning means comprises a plurality of receiving coils.  
     
     
         53 . The system of  claim 52 , wherein the plurality of receiving coils comprises at least three receiving coils.  
     
     
         54 . The system of  claim 53 , wherein the plurality of receiving coils comprises at least four receiving coils.