High‐speed black blood imaging of vessel stenosis in the presence of pulsatile flow

Stenosis phantoms were created to study the ability of “black blood” methods to image a vessel stenosis in the presence of pulsatile flow. Black blood images were acquired with a modified TurboFLASH (fast low‐angle shot) method that eliminates flow signal by applying a set of prepulses before segmented data acquisition. With this high‐speed approach, imaging can be completed within 16 seconds. This technique was compared with conventional spin‐echo black blood, gradient‐echo black blood, and gradient‐echo bright blood methods. Loss of flow signal, which extended beyond the site of the stenosis, was seen on the gradient‐echo bright blood images. The pattern of signal loss varied with the type of stenosis. Flow voids were achieved with spin‐echo black blood imaging: however, substantial ghosting artifacts were seen. With gradient‐echo black blood imaging, it was difficult to eliminate all flow signal, particularly for in‐plane flow. The modified TurboFLASH method produced high‐quality black blood images in a fraction of the time needed for spin‐echo imaging. It showed no ghosting artifacts even in the presence of pulsatile flow.