BACKGROUND AND PURPOSE Because it diminishes the stiffness of the intervertebral disk, disk degeneration results in abnormal motions of the spine. Therefore, disk degeneration associated with back pain may indicate spinal fusion. The purpose of this study was to correlate the MR appearance and stiffness of lumbar intervertebral disks. METHODS Eighty-two lumbar spinal segments were imaged with...

A method is presented for estimating the background at a given location on a sky map by interpolating the estimated background from a set of concentric annuli which surround this location. If the background is nonuniform but smoothly varying, this method provides a more accurate (though less precise) estimate than can be obtained with a single annulus. Several applications of multi-annulus back...

An annulus is, informally, a ring-shaped region, often described by two concentric circles. The maximum-width empty problem asks to find an of certain shape with the maximum possible width that avoids given set n points in plane. This can also be interpreted as finding optimal location obnoxious facility among input points. In this paper, we study square and rectangular variants problem, presen...

Introduction: In health, the intervertebral disc is generally avascular and sparsely innervated. Those few nerves and blood vessels present are generally restricted to the outer areas of the annulus fibrosus where they lie predominantly between concentric layers of matrix (called lamellae). During disc degeneration, however, many more nerves are seen within the annulus, often in association wit...