Angled segment receiver coil for nmr imaging of a human head

Abstract

An RF receiver coil structure for NMR imaging of a human head attached by a neck to a body (normally lying horizontally), having ear positions, and having a defined axis generally along a line extending from the top of the head through the neck. The coil lies primarily in a coil plane which is horizontal, and thus is properly oriented with reference to the main field orientation of an NMR system. The coil is generally oval in configuration, having sides and defined upper and lower ends spaced by an oval height. The coil is sized for positioning around the head oriented such that the coil upper end is adjacent to the top of the head, the coil sides are generally adjacent to the ear positions, and the defined head axis lies in the defined coil plane. The coil includes an angled segment defined as having a midpoint at the coil lower end and which extends from the midpoint along the coil sides towards the coil upper end for a distance corresponding to approximately one-third of the oval height, terminating at segment endpoints. The angled segment thus diverges beginning at the segment endpoints out of the coil plane at an angle such that the coil lower end clears the neck when positioned around the head. The coil is formed of a tubular conductor, having a tubular diameter (outside diameter) in the approximate range of from 3/8 inch to 3/4 inch. The coil has terminal ends at its upper end at which a component unit is located. The component unit includes a capacitor electrically connected to the coil terminal ends to form a parallel resonant circuit.