3D image reconstruction method for placing 3D structure within common oblique or contoured slice-volume without loss of volume resolution

#This invention generally deals with three-dimensional image processing. More particularly, it deals with method and apparatus for reconstructing an existing three dimensional image so that a three-dimensional structure passing through plural slice-volumes of the original image can be shifted into a common slice or contour-volume without loss of volume resolution. The invention has particular (but not exclusive) application for processing three-dimensional images obtained by magnetic resonance imaging (MRI).

#MRI is now in widespread commercial usage. Some examples of prior art MRI methods and apparatus including methods for three-dimensional image construction may be found, for example, in prior issued commonly assigned U.S. Pat. Nos. 4,297,637; 4,318,043; 4,471,305; and 4,599,565. The contents of these referenced related patents are hereby incorporated by reference.

#A is already well-known in the art, a three-dimensional MRI data set may be created in a number of ways. For example, nuclear magnetic resonance RF data may be elicited from a plurality of parallel contiguous slice-volumes and phase encoded in two different dimensions (e.g., x,y) so that the NMR hydrogen (or other NMR sensitive nuclear) density may be calculated for each volume element (voxel) within a given slice-volume using two-dimensional Fourier transform techniques. Another known technique obtains nuclear magnetic resonance RF data from an entire three-dimensional volume including phase encoding in three dimensions (e.g., x,y,z) which then produces similar voxel values for plural substantially parallel and contiguous slice-volumes after three dimensions of Fourier transformation.

#These as well as other objects and advantages of this invention will be more completely understood and appreciated by studying the following more detailed description of presently preferred exemplary embodiments of this invention in conjunction with the accompanying drawings of which:

#FIG. 1 is a schematic simplified representation of a typical magnetic resonance imaging system modified so as to practice this invention;

#FIG. 2 is a schematic depiction of typical prior art spatial domain interpolation processes or rectilinear frequency domain phase shift processes;

#The novel three-dimensional image processing procedure utilized by this invention typically can be achieved by suitable alteration of stored controlling computer programs in existing MRI apparatus. As an example of such typical apparatus, the block diagram of FIG. 1 depicts the general architecture of such a system.

#Typically, a human or animal subject (or other object) 10 is placed within a static magnetic field. For example, the subject may lie along the z-axis of a static magnet 8 which establishes a substantially uniform magnetic field directed along the z-axis within the portion of the object 10 of interest. For example, contiguous parallel slice-volumes p,q . . . z may be located within the volume to be imaged. Gradients may be imposed within this z-axis directed magnetic field along mutually orthogonal x,y,z axes by a set of x,y,z gradient amplifiers and coils 14. NMR RF signals are transmitted into the body 10 and NMR RF responses are received from the body 10 via RF coils 16 connected by a conventional transmit/receive switch 18 to an RF transmitter 20 and RF receiver 22. As will be appreciated by those in the art, separate transmit and receive coils may be used in some installations in which case the T/R switch 18 may not be needed.

#All of the prior mentioned elements may be controlled, for example, by a control computer 24 which communicates with a data acquisition and display computer 26. The latter computer 26 may also receive NMR responses via an analog-to-digital converter 28. A CRT display and keyboard unit 30 is typically also associated with the data acquisition and display computer 26.