Abstract

Methods: We implemented a pulse sequence that allows for a control of ramp up/down of gradients, capable of gradual increase of acoustic noise (see Fig 1a), to facilitate subject’s natural sleep onset. Experiments were performed on a GE 1.5 T scanner (max gradient amplitude= 40 mT/m, max slew-rate= 150 T/m/s) with a custom 4-ch upper airway coil and a custom real-time imaging platform [6]. Two adult male subjects participated in the MRI study. Each subject lay supine. Each subject’s head was immobilized with foam pads. An optical microphone was placed 5 to 10 cm anterior to the mouth. Imaging parameters: FOV= 24× 24 cm2, slice thickness= 8 mm, spiral GRE, 30 spiral interleaves, 2.0× 2.0 mm2 resolution, 472.2 ms temporal resolution, TR= 15.74 ms. Gradient waveform design was made with a max gradient slew rate of 75 T/m/s. Scan was continuous for approximately 20 minutes. Image frames were …

Date

2013

Authors

Yoon-Chul Kim, Michael I Proctor, Michael CK Khoo, Shrikanth S Narayanan, Krishna S Nayak

Journal

Proceedings of the International Society for Magnetic Resonance in Medicine, 21st Annual Meeting and Exhibition, Salt Lake City, Utah, USA

Volume

21

Pages

1235