Changes in cross-sectional measurements of the spinal canal and intervertebral foramina as a function of body position: In vivo studies on an open-configuration MR system

Citation
Mr. Schmid et al., Changes in cross-sectional measurements of the spinal canal and intervertebral foramina as a function of body position: In vivo studies on an open-configuration MR system, AM J ROENTG, 172(4), 1999, pp. 1095-1102
Citations number
24
Categorie Soggetti
Radiology ,Nuclear Medicine & Imaging","Medical Research Diagnosis & Treatment
Journal title
AMERICAN JOURNAL OF ROENTGENOLOGY
ISSN journal
0361803X → ACNP
Volume
172
Issue
4
Year of publication
1999
Pages
1095 - 1102
Database
ISI
SICI code
0361-803X(199904)172:4<1095:CICMOT>2.0.ZU;2-R
Abstract
OBJECTIVE, The purpose of this study was to evaluate physiologic changes of the cross-sectional area of the spinal canal and neural foramina in young asymptomatic volunteers. SUBJECTS AND METHODS. Twelve asymptomatic volunteers were examined in a 0.5 -T open-configuration MR system. T2-weighted fast spin-echo sequences were obtained in upright neutral, upright flexed, upright extended, and supine e xtended positions. The cross-sectional area of the spinal canal and the thi ckness of the ligamentum flavum were measured on angled axial images at the L4-L5 level. The anteroposterior diameter of the spinal canal and cross-se ctional areas of the neural foramina were measured on sagittal images from L1 to S1, RESULTS. At disk level, the cross-sectional area of;he spinal canal vaned s ignificantly between body positions, most notably between the upright flexe d (mean, 268 mm(2)) and the upright extended (mean, 224 mm(2)) positions (p < .0001), The maximum thickness of the Ligamenta flava increased in the ex tended positions (p < .0001). The cross-sectional area of the neural forami na underwent position-dependent variations of as much as 44.4%. The smalles t cross-sectional areas were found in the extended positions. CONCLUSION. In asymptomatic volunteers, MR imaging is able to show position -dependent changes in the cross-sectional areas of the spinal canal and the intervertebral foramina, The extended positions best reveal important find ings.