Section thickness and contiguity phantom for MR imaging.

Magnetic resonance (MR) imaging systems are uniquely able to acquire data simultaneously for the reconstruction of images from multiple sections, that is, for volumes up to 20 cm or more in length and for axial, coronal, and sagittal planes. A phantom has been developed that allows one to determine if the sections are of the desired thickness throughout the volume, if the sections are contiguous or the section spacing is as specified, if the central section is at the appropriate location, if the profile of the section is as specified by the manufacturer, if the signal strength is uniform for all sections, that the signal strength decreases in a consistent manner for second and subsequent echo images, and that gross spatial distortions are not present. Such measurements are essential for acceptance testing and quality control purposes over reasonably long volumes. The details of this new phantom are described, and results of its use with both low-and high-field-strength MR imaging systems are presented.