Oblique Reformatting of Multislice Magnetic Resonance Images for Improved Visualization of Coronary Arteries

A technique for reformatting multislice magnetic resonance images into arbitrary oblique planes has been developed and implemented on a Toshiba MRT-35 (formerly Diasonics MT/S) imaging system (South San Francisco, CA). This method is designed to allow the user to easily define a new plane by marking with a cursor features of interest, on two or three different image levels. These features are combined in the resulting oblique image. The reformatted image can have arbitrary angulation and is created with a pixel dimension equivalent to the original data set. Resolution ranges from the original in-plane resolution to the slice thickness, depending on angulation. An improvement in signal-to-noise ratio results from the effective averaging performed by interpolation. this method is optimally used to correct for small variations in alignment, such as the positioning of the intervertebral disks. It can also be used to generate reformatted images at many different angles from a single multislice data set. This method has been applied to the particular problem of improving the presentation of coronary arteries on a conventional set of multislice spin-echo cardiac images by increasing the visible length of individual coronary segments.