Functional MRI of the spine: different patterns of positions of the forward flexed lumbar spine in healthy subjects

Abstract

IntroductionImaging of the flexed and extended spine has been carried out since the first half of the 20th century using lateral radiographs [3,8]. With this technique, the examined subject is exposed to ionizing radiation with no assessment of soft tissues or axial plane imaging. Magnetic resonance imaging (MRI) provides excellent anatomical details in all planes without exposure to ionizing radiation. In the past, restrictions existed for functional lumbar spinal imaging, because of the systems' configuration. With the development of open MR scanners this problem has been partly overcome [4,6,9]. Because of ongoing developments and improvements in image quality, it is possible to reduce motion artifacts by decreasing acquisition time. Although functional MRI of the lumbar spine is not yet a standard diagnostic procedure, in the future it is likely to be used for diagnostic entities such as discoligamentous instability or position-dependent spinal stenosis.To assess pathological findings by a new diagnostic method, it is necessary first to investigate physiological conditions. The purpose of this study was to establish the best setup for MRI of the forward flexed lumbar spine, describe the findings in a group of asymptomatic subjects and correlate them with the orientation of the facet joints.Abstract Since the introduction of the technique of vertical open-configuration systems, efforts have been made to obtain functional lumbar spinal magnetic resonance (MR) images. The purpose of this study was to determine the relation between facet joint orientation and flexion patterns in the lower lumbar spine. Thirty-four normal subjects (18 women, 16 men) were examined in a vertical open 0.5-T MR scanner with T1-weighted gradient echo (GE) sequences. Flexion angles were digitally measured in the sagittal plane and facet joint orientation in the axial plane. The population showed three different functional flexion patterns: 17.6% (n=6) had kyphotic angles in all three lower lumbar levels during forward flexion (type 1), 50% (n=17) had a lordotic angle at L5/S1 but kyphotic angles at L4/L5 and L3/L4 (type 2), and 32.4% (n=11) showed lordotic angles at L5/S1 and L4/L5 but a kyphotic angle at L3/L4 (type 3). There were statistically significant differences between flexion patterns and mean facet joint orientation: at L4/L5 33.3°for type 1, 33.5°f or type 2 and 46.2°for type 3; at L5/S1 27.2°for type 1, 46.4°for type 2 and 48.1°for type 3. There were no significant differences between the three groups at L3/L4. The three different flexion patterns in normal subjects and their relation to facet joint orientation have not been described previously. Knowledge of these patterns may lead to a better understanding of physiological spinal movement as a base for future investigations in low back pain patients.

Effects of Sagittal Endplate Shape on Lumbar Segmental Mobility as Evaluated by Kinetic Magnetic Resonance Imaging

“…The use of kMRI may be helpful in these situations in determining spinal stability. [25][26][27][28][29] Combined with digital imaging software that allows for accurate and precise quantifi cation of spinal motion, kMRIs could potentially help spine surgeons create more complete clinical assessments of their patients in some situations. 30 , 31 Previous reports have shown that disc degeneration is strongly associated with changes in segmental motion.…”

Anatomical data on the craniocervical junction and their correlation with degenerative changes in 30 cadaveric specimens

“…5,7,13,17 Asymmetry of craniocervical joints occurred in 58% at the occiput-C1 levels and in 46% at the C1-2 levels in a study by Pfirrmann and colleagues. 12 This is often noted in daily clinical practice while analyzing computerized tomography or magnetic resonance images of the spine.…”

Hybrid Solutions for the Surgical Treatment of Multilevel Degenerative Cervical Disk Disease

“…A modification of White and Panjabi's method was used with the Cobb angle measurement tool (Centricity Enterprise Web V3.0 software, GE Healthcare, Little Chalfont, United Kingdom) to measure the ROM angles. [16][17][18] Angle values in kyphosis, as usually observed in flexion (►Fig. 1A, C), were recorded as positive values, and angle values in lordosis, as usually observed in extension, were recorded as negative values (►Fig.…”