Magnetic Resonance Imaging In Supine Position Research Articles

Effect of a mattress on lumbar spine alignment in supine position in healthy subjects: an MRI study

BackgroundHumans should sleep for about a third of their lifetime and the choice of the mattress is very important from a quality-of-life perspective. Therefore, the primary aim of this study was to assess the changes of lumbar angles, evaluated in a supine position using magnetic resonance imaging (MRI), on a mattress versus a rigid surface.MethodsTwenty healthy subjects (10 females, 10 males), aged 32.3 ± 6.5 (mean ± standard deviation), with body mass index 22.4 ± 2.9, completed three evaluations: (i) spine MRI in supine position on a mattress (MAT); (ii) spine MRI in supine position on rigid surface (CON); and (iii) biplanar radiographic imaging in standing position. The following indexes were calculated for both MAT and CON: lumbar lordosis angles L1–L5, L1–S1, L5–S1, and the sacral slope (SS). Further, pelvic incidence (PI) was calculated from the biplanar radiographic images.ResultsMain findings were (i) L1–L5 and SS were greater in MAT than CON (L1:L5: +2.9°; SS: +2.0°); (ii) L5–S1 was lower in MAT than CON (−1.6°); (iii) L1–S1 was greater in MAT than CON only for male subjects (+2.0°); (iv) significant and positive correlations between PI and L1–L5, L1–S1 and SS were observed in both CON and MAT.ConclusionsThe use of a mattress determined small but statistically significant changes in lumbar angles.Relevance statementThe use of a mattress determines small but statistically significant changes in radiological angles describing the sagittal alignment of the lumbar spine when lying in the supine position.Key points• Lordosis angle L1–L5 was greater in MAT than in CON condition (+2.9°).• Sacral slope was greater in MAT than in CON condition (+2.0°).• Lordosis angle L5–S1 was lower in MAT than in CON condition (−1.6°).Graphical

Comparative Analysis of Evaluation of Lumbar Lordosis Measured in the Standing Positions Radiography and Magnetic Resonance Imaging

IntroductionResearch of degenerative diseases of the spine it is recommended performing radiographs and magnetic resonance imaging (MRI). Physiological curvature of the lumbar spine varies from 35 to 50. Changes sagittal alignment can lead to changes in the lumbar spine kinematics, having influence on the support and load distribution on the spine, causing low back pain. Methods100 patients with chronic low back pain (51 men and 49 women), being evaluated degree of lumbar lordosis by three independent examiners by radiography in the standing position and MRI in supine position with flexed lower limbs. Measurement of lumbar lordosis by the Cobb method (L1 to L5 levels) in lumbar radiographs in profile and in the sagittal plane in lumbar MRI. ResultsAverage of lumbar curvature on X-rays and the MRI cushion was 42,2° and 31,5°, respectively (p value < 0.001). Average angles of lumbar lordosis by MRI underestimates by 25% compared with lumbar radiographs. ConclusionMRI is insufficient for evaluation of lumbar lordosis, it underestimates the true lumbar lordosis. Thus, the lumbar radiological evaluation is essential in assessing the true lumbar lordosis.

Measurement of vertebral rotation in adolescent idiopathic scoliosis with low-dose CT in prone position - method description and reliability analysis.

BackgroundTo our knowledge there is no report in the literature on measurements of vertebral rotation with low-dose computed tomography (CT) in prone position.AimsTo describe and test the reliability of this new method, compare it with other methods in use and evaluate the influence of body position on the degree of vertebral rotation measured by different radiological methods.Study designRetrospective study.Methods25 consecutive patients with adolescent idiopathic scoliosis scheduled for surgery (17 girls, 8 boys) aged 15 ± 2 years (mean ± SD) were included in the analysis of this study. The degree of the vertebral rotation was in all patients measured according to the method of Perdriolle on standing plain radiographs and on supine CT scanogram, and according to the method of Aaro and Dahlborn on axial CT images in prone position and on magnetic resonance imaging (MRI) in supine position. The measurements were done by one neuroradiologist at two different occasions. Bland and Altman statistical approach was used in the reliability assessment.ResultsThe reliability of measuring vertebral rotation by axial CT images in prone position was almost perfect with an intraclass correlation coefficient of 0.95, a random error of the intraobserver differences of 2.3°, a repeatability coefficient of 3.2° and a coefficient of variation of 18.4%. Corresponding values for measurements on CT scanogram were 0.83, 5.1°, 7.2°, and 32.8%, respectively, indicating lower reliability of the latter modality and method. The degree of vertebral rotation measured on standing plain radiographs, prone CT scanogram, axial images on CT in prone position and on MRI in supine position were 25.7 ± 9.8°, 21.9 ± 8.3°, 17.4 ± 7.1°, and 16.1 ± 6.5°, respectively. The vertebral rotation measured on axial CT images in prone position was in average 7.5% larger than that measured on axial MRI in supine position.ConclusionsThis study has shown that measurements of vertebral rotation in prone position were more reliable on axial CT images than on CT scanogram. The measurement of vertebral rotation on CT (corrected to the pelvic tilt) in prone position imposes lower impact of the recumbent position on the vertebral rotation than did MRI in supine position. However, the magnitude of differences is of doubtful clinical significance.