Direct cerebral and cardiac 17O-MRI at 3 Tesla: initial results at natural abundance

To establish direct O-17-magnetic resonance imaging (MRI) for metabolic imaging at a clinical field strength of 3 T. An experimental setup including a surface coil and transmit/receive switch was constructed. Natural abundance in vivo brain images of a volunteer were acquired with a radial three-dimensional (3D) sequence in the visual cortex and in the heart with electrocardiogram (ECG)-gating. In the brain, a signal-to-noise ratio of 36 was found at a nominal resolution of (5.6 mm)(3), and a transverse relaxation time of T-2* = (1.9 +/- A 0.2) ms was obtained. In the heart O-17 images were acquired with a temporal resolution of 200 ms. Cerebral and cardiac O-17-MRI at natural abundance is feasible at 3 T.