Real‐time acquisition, display, and interactive graphic control of NMR cardiac profiles and images

A highly interactive MRI scanner interface has been developed that allows, for the first time, real‐time graphic control of one‐dimensional (1D) and two‐dimensional (2D) cardiac MRI exams. The system comprises a Mercury array processor (AP) in a Sun SPARCserver with two connections to the MRI scanner, a data link that passes the NMR data directly to the AP as they are collected, and a control link that passes commands from the Sun to the scanner to redirect the imaging pulse sequence in real time. In the 1D techniques, a cylinder or “pencil” of magnetization is repeatedly excited using gradient‐echo or spin‐echo line‐scan sequences, with the magnetization read out each time along the length of the cylinder, and a scrolling display generated on the Sun monitor. Rubber‐band lines drawn on the scout image redirect the pencil or imaging slice to different locations, with the changes immediately visible in the display. M‐mode imaging, 1D flow imaging, and 2D fast cardiac imaging have been demonstrated on normal volunteers using this system. This platform represents an operator‐“friendly” way of directing real‐time imaging of the heart.