High-Resolution Single-Slice MR Myelography

Abstract

R myelography is a noninvasive technique that can provide anatomic information about the subarachnoid space. Major advantages of MR myelography over conventional radiographic myelography include its lack of ionizing radiation, noninvasive nature, and lack of need for intrathecal contrast material [1]. Two techniques, based on slice selection, are currently in use: multislice MR myelography and single-slice MR myelography. Multislice MR myelography requires a relatively long imaging time. The image quality is often degraded by artifacts arising from cerebrospinal fluid pulsatile flow and background signal contribPictorial Essay M A B Fig. 1.-Single-slice MR myelography in healthy 35-year-old male volunteer. A, Cervical spine single-slice MR myelogram obtained in posterior view shows spinal cord as filling defect in thecal sac containing hyperintense cerebrospinal fluid. Nerve root sleeves are shown as symmetric tentlike or sleevelike protrusions from thecal sac margin (arrows). B, Lumbar spine single-slice MR myelogram obtained in posterior view shows individual nerve roots (arrows) extending from spinal cord to nerve root sleeves and cauda equina.Fig. 2.-Conjoined nerve root in 39-year-old man. Single-slice MR myelogram reveals that two nerve roots (arrow) of right side share common proximal sleeve at level of sacrum. Tortuous fine vessel (arrowheads) on surface of lumbosacral spinal cord is normal finding. Downloaded from www.ajronline.org by 203.115.120.250 on 10/04/15 from IP address 203.115.120.250.

MR-myelography as an adjunct to the MR examination of the degenerative spine

“…Although in other studies two and three images from different angles were obtained [15,18], in our study four projections were acquired to evaluate accurately the nerve roots and their emergencies towards the extradural space [5][6][7]. The accurate visualization of the nerve roots, thecal sleeves and root emergences may generate very important, useful information for the final MR diagnosis.…”

“…TSE sequences, in which the echo train is large enough to cover all (single-shot) or most (segmented multi-shot) lines of the k space within a single TR (repetition time) [4], can be used to generate myelographic images. Although this TSE technique has revealed high quality myelograms [15,17,18], MR-myelography examinations were initially performed by most authors with postprocessing MIP projections from conventional T2-weighted images obtained in very long acquisition times [8,11,14]. MR-myelography obtained with the TSE single-or multi-shot single-slice technique allows the simultaneous acquisition of several different planes within the same sequence, obtained in shorter acquisition times and with fewer artifacts [4,15,18].…”

“…Keywords MR-myelography Á MR comparative studies Á MR spine single-slice TSE myelography images are gaining acceptance [4,15].…”

Technical Advancements and Utilization of Spine Surgery -International Disparities in Trend-Dynamics Between Japan, Korea, and the USA

“…The advent of high magnetic field MRI 6,31,66) and multi-detector CT with capability of helical or spiral scanning, 14) and subsequent development of computer processing of the data such as multiplanar reconstructions (MPR) or maximum intensity projections, 25,36,40,59) enhanced enormously the amount and the availability of information we obtain from neuroimaging studies. This has provided hitherto unavailable insights regarding the pathological processes taking place inside the spinal cord and the nerve roots.…”

“…It is useful for delineation of impingement of the nerve roots. 25,36,59) Diffusion tensor imaging (fiber tracking), MR spectroscopy with and without mapping, and functional MRI are all P. Kim et al being tried in the spinal cord, but we still have to wait for further development of the applications to become useful in our practices. 50,53,54) …”