MR imaging of flow with locally high spatial resolution

Abstract

Locally focused magnetic resonance imaging (LF MRI) allows imaging with variable spatial resolution within the field of view (FOV). Because LF MRI uses a priori information to provide locally high resolution in regions with rapid spatial variations in intensity (e.g., blood/tissue interface), it allows accurate reproduction of intense sharp edges in the specimen without blurring and truncation artifacts. This study employs LF MRI for 3D imaging of stationary and pulsatile flow. In the implemented version of LF MRI analytically defined basis functions are used to determine image intensity in regions depicted with low or high resolution. It is demonstrated that LF MRI of flow allows a significant (i.e. 3–4 times) reduction in scan time as compared to conventional FT MRI. It is also shown that LF images of pulsatile flow have a decreased appearance of ghosting artifacts as compared to the images reconstructed by using the conventional method.