Pseudocontinuous arterial spin labeling with prospective motion correction (PCASL-PROMO).
OBJECTIVE
Arterial spin labeling (ASL) perfusion imaging with a segmented three-dimensional (3D) readout is becoming increasing popular, yet conventional motion correction approaches cannot be applied in segmented imaging. The purpose of this study was to demonstrate the integration of 3D pseudocontinuous ASL (PCASL) and PROMO (PROspective MOtion correction) for cerebral blood flow measurements.


METHODS
PROMO was integrated into 3D PCASL without increasing repetition time. PCASL was performed with and without PROMO in the absence of motion. The performance of PCASL-PROMO was then evaluated with controlled motions using separate scans with and without PROMO and also with random motion using an interleaved scan where every repetition time is repeated twice, once with and once without PROMO.


RESULTS
The difference in the average ASL signal of the 3D volume between conventional and PROMO implementations was negligible (<0.2%). ASL image artifacts from both controlled and random motions were removed significantly with PROMO, showing improved correlation with reference images. Multiple combinations of data acquired using the interleaved scan revealed that PROMO with real-time motion updating alone reduces motion artifact significantly and that rescanning of corrupted segments is more critical in tagged images than control images.


CONCLUSIONS
This study demonstrates that PROMO is a successful approach to motion correction for PCASL cerebral blood flow imaging.
Department of Radiology, Stanford University, Stanford, California, USA.
Zungho
Z
Zun
Ajit
A
Shankaranarayanan
Greg
G
Zaharchuk
D000465:Algorithms; D016477:Artifacts; D001783:Blood Flow Velocity / Q000502:physiology*; D001921:Brain / Q000098:blood supply / Q000502:physiology*; D002536:Cerebral Arteries / Q000033:anatomy & histology / Q000502:physiology; D002560:Cerebrovascular Circulation / Q000502:physiology*; D007089:Image Enhancement / Q000379:methods*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D021621:Imaging, Three-Dimensional / Q000379:methods; D018810:Magnetic Resonance Angiography / Q000379:methods*; D009038:Motion; D012016:Reference Values; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013113:Spin Labels
D013113:Spin Labels
ASL; PCASL; PROMO; arterial spin labeling; prospective motion correction