Methods of rendering vascular morphology in mri with multiple contrast acquisition for black-blood angiography

Abstract

A black blood magnetic resonance angiogram is produced by exciting dipoles ( ) and repeatedly inverting the resonance ( , . . . ) to produce a series of magnetic resonance echoes ( , . . . ). Early echoes (e.g., ( )) are more heavily proton density weighted than later echoes (e.g., ( )), which are more heavily T weighted. The magnetic resonance echoes are received and demodulated ( ) into a series of data lines. The data lines are sorted ( ) between the more heavily proton density weighted data lines and T weighted data lines which are reconstructed into a proton density weighted image representation and a T weighted image representation. The proton density weighted and T weighted image representations are combined ( ) to emphasize the black blood from the T weighted images and the static tissue from the proton density weighted image. The combination processor ( ) scales ( ) the PDW and T W images to a common maximum intensity level. The PDW and T W image representations are then combined, e.g. averaged, together ( ) to form a combined or averaged image. An edge image ( ) is computed from the T W image and a threshold mask ( ) is applied. The edge image ( ) is combined ( ) with the combined image ( ) to form an edge enhanced image. Optionally, a minimum projection intensity algorithm ( ) is applied to the enhanced image. Preferably, the enhanced image is a black blood magnetic resonance angiogram with emphasized blood vessel edges.