Abstract: An NMR radio frequency (RF) surface coil allows the user to continuously vary the size of the field of view. The surface coil utilizes a modified radio frequency trombone for size adjustment that results in a stable resonant frequency of the coil over a wide range of dimensions such that retuning of the coil is unnecessary with changes in dimensions and variation of the field of view. The coil may be increased in area by as much as 60 percent while maintaining frequency stability to 1 MHz at 63.5 MHz and 2 MHz for full extension of 10 cm. The coil is readily adapted for imaging of the human spine, but can also be utilized for imaging other anatomical features.

Abstract: An RF receiver coil structure for NMR imaging of cardiac and thoraco-abdominal regions of a human body. The coil structure includes a coil of generally solenoidal geometry having two turns separated by an inter-element gap. The inter-element gap is sufficiently large to accommodate an average human torso at the chest level (e.g. 25 cm). The turns are cross coupled by a pair of crossed diagonal elements. The coil is formed of a tubular conductor, having a tubular diameter (outside diameter) of approximately 1/2 inch. The coil has terminal ends in one of its diagonal elements, and the coil structure further includes a component unit located where the diagonal elements cross. The component unit includes a capacitor electrically connected to the coil to form a parallel resonant circuit. The same geometry may be employed in a multi-turn structure, where preferably one-half of the total number of turns are positioned above the patient, and the other half below the patient.

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.