Mapping of arterial transit time using dual-coil CASL with sinusoidally modulated labeling function
Mildner T, Mller K, Hetzer S, Driesel W, Trampel R, Mller H
Max Planck Institute for Human Cognitive and Brain Sciences
A new method for arterial transit time mapping in the human brain using dual-coil CASL is demonstrated. Perfusion contrast is created using a circular double-loop coil (6-cm diameter each loop), which was placed over both common carotid arteries. The method is characterized by short TR's in the range of 500 - 750 ms and a frequency-swept continuous labeling RF for the creation of a quasi-sinusoidally modulated labeling function at the neck. The evaluation of the experiments was performed using spectral methods which provide a measure of coherence and phase shift at this frequency. This information is used to compute maps of the arterial transit time. Robust maps of the arterial transit time with arbitrary slice orientation were obtained in about 4 minutes.