Herman the helpful octopus is always willing to assist anyone who needs his help--old or young, friend or enemy.

This book is designed to introduce the reader to the field of NMR/MRI at very low magnetic fields, from milli-Tesla to micro-Tesla, the ultra-low field (ULF) regime. The book is focused on applications to imaging the human brain, and hardware methods primarily based upon pre-polarization methods and SQUID-based detection. The goal of the text is to provide insight and tools for the reader to better understand what applications are best served by ULF NMR/MRI approaches. A discussion of the hardware challenges, such as shielding, operation of SQUID sensors in a dynamic field environment, and pulsed magnetic field generation are presented. One goal of the text is to provide the reader a framework of understanding the approaches to estimation and mitigation of low signal-to-noise and long imaging time, which are the main challenges. Special attention is paid to the combination of MEG and ULF MRI, and the benefits and challenges presented by trying to accomplish both with the same hardware. The book discusses the origin of unique relaxation contrast at ULF, and special considerations for image artifacts and how to correct them (i.e. concomitant gradients, ghost artifacts). A general discussion of MRI, with special consideration to the challenges of imaging at ULF and unique opportunities in pulse sequences, is presented. The book also presents an overview of some of the primary applications of ULF NMR/MRI being pursued.

Leo isn’t reading, or writing, or drawing, or even speaking, and his father is concerned. But Leo’s mother isn’t. She knows her son will do all those things, and more, when he’s ready. ‘Reassuring for other late bloomers, this book is illustrated with beguiling pictures.’—Saturday Review.

When little mouse accepts the cat's invitation to play, he doesn't know what kind of game the cat really has in mind. "A splendid picture book with brilliantly colored and expressive illustrations, funny and exciting."--Horn Book.