title: Comparison of Lumbar Lordosis in Lateral Radiographs in Standing Position with supine MR Imaging in consideration of the Sacral Slope.
abstract: PurposeTo investigate the influence of sacral slope on the correlation between measurements of lumbar lordosis obtained by standing radiographs and magnetic resonance images in supine position (MRI). Little information is available on the correlation between measurements of lumbar lordosis obtained by radiographic and MR images. Most relevant studies have shown correlations for the thoracic spine, but detailed analyses on the lumbar spine are lacking.MethodsMR images and standing lateral radiographs of 63 patients without actual low back pain or radiographic pathologies of the lumbar spine were analyzed. Standing radiographic measurements included the sagittal parameters pelvic incidence (PI) pelvic tilt (PT), and sacral slope (SS); MR images were used to additionally measure lumbar L1-S1 lordosis and single level lordosis. Differences between radiographic and MRI measurements were analyzed and divided into 4 subgroups of different sacral slope according to Roussouly's classification.ResultsGlobal lumbar lordosis (L1-S1) was 44.99° (± 10 754) on radiographs and 47.91° (± 9.170) on MRI, yielding a clinically relevant correlation (r = 0.61, p < 0.01). Measurements of single level lordosis only showed minor differences. At all levels except for L5 / S1, lordosis measured by means of standing radiographs was higher than that measured by MRI. The difference in global lumbar L1-S1 lordosis was -2.9°. Analysis of the Roussouly groups showed the largest difference for L1-S1 (-8.3°) in group 2. In group 4, when measured on MRI, L5 / S1 lordosis (25.71°) was lower than L4 / L5 lordosis (27.63°) compared to the other groups.ConclusionsAlthough measurements of global lumbar lordosis significantly differed between the two scanning technologies, the mean difference was just 2.9°. MRI in supine position may be used for estimating global lumbar lordosis, but single level lordosis should be determined by means of standing radiographs.Key Points· Large difference between radiographic and MRI measurements of level L5 / S1.. · MRI can be used for estimating global lumbar lordosis.. · Analysis of single level lordosis necessitates measurement in standing radiographs..Citation Format· Benditz A, Boluki D, Weber M et al. Comparison of Lumbar Lordosis in Lateral Radiographs in Standing Position with supine MR Imaging in consideration of the Sacral Slope. Fortschr Röntgenstr 2017; 189: 233 - 239.
authors.affiliation: Orthopedic Surgery, University Medical Center Regensburg, Bad Abbach/Regensburg, Germany.
authors.forename: Achim
authors.initials: A
authors.lastname: Benditz
authors.affiliation: Orthopedic Surgery, University Medical Center Regensburg, Bad Abbach/Regensburg, Germany.
authors.forename: Daniel
authors.initials: D
authors.lastname: Boluki
authors.affiliation: Orthopedic Surgery, University Medical Center Regensburg, Bad Abbach/Regensburg, Germany.
authors.forename: Markus
authors.initials: M
authors.lastname: Weber
authors.affiliation: Center for Clinical Studies, University Medical Center Regensburg, Germany.
authors.forename: Florian
authors.initials: F
authors.lastname: Zeman
authors.affiliation: Orthopedic Surgery, University Medical Center Regensburg, Bad Abbach/Regensburg, Germany.
authors.forename: Joachim
authors.initials: J
authors.lastname: Grifka
authors.affiliation: Orthopedic Surgery, University Medical Center Regensburg, Bad Abbach/Regensburg, Germany.
authors.forename: Florian
authors.initials: F
authors.lastname: Völlner
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D059925:Anatomic Landmarks / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D008141:Lordosis / Q000000981:diagnostic imaging*; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D056888:Patient Positioning / Q000379:methods*; D015203:Reproducibility of Results; D012447:Sacrum / Q000000981:diagnostic imaging*; D012680:Sensitivity and Specificity; D016683:Supine Position