European Spine Journal (2018) 27:1408–1415
Correlation and dierences in cervical sagittal alignment parameters
between cervical radiographs and magnetic resonance images
· Masashi Tanaka
· Yasushi Oshima
· Sakae Tanaka
· K. Daniel Riew
Received: 22 August 2017 / Revised: 14 February 2018 / Accepted: 13 March 2018 / Published online: 23 March 2018
© Springer-Verlag GmbH Germany, part of Springer Nature 2018
Purpose Although cervical alignment is better assessed using standing radiography than supine magnetic resonance imaging
(MRI), few studies have investigated this. This study aimed to investigate the diﬀerence in alignment between standing radio-
graphs and supine MRI images, and assess whether neck position aﬀects the cervical parameters and neurological changes.
Methods We analyzed 53 patients, measuring the O–C2 angle, C2–7 angle (the distinction between the lordotic and kyphotic
groups), T1 slope, neck tilt, thoracic inlet angle, and the C2–7 sagittal vertical axis. Inter- and intra-group analyses were
conducted to identify any diﬀerence between standing radiography and supine MRI. Statistical diﬀerences between the
cervical parameters were compared.
Results Strong correlations were noted between the equivalent parameters in the radiographs and MRI images, whereas no
signiﬁcant diﬀerence was observed in C2–7 angle in the kyphotic group between the radiographs and MRI images, or for
neck tilt between the radiographs and MRI images. However, in the lordotic group, the C2–7 angle was signiﬁcantly diﬀer-
ent between the two types of images and larger in the radiographs than in the MRI images (C2–7 angle in the radiographs:
C2–7 angle in the MRI images: 4.49°, p < 0.001).
Conclusions Neck tilt was a constant parameter. The C2–7 angle in the kyphotic group was similar between the standing
radiographs and the supine MRI images; however, the C2–7 angle in the lordotic group was diﬀerent. Therefore, we recom-
mend that standing cervical radiographs should be preoperatively obtained for all surgical patients.
Graphical abstract The slides can be retrieved under Electronic Supplementary Material.
1. Cervical parameters
2. Standing radiograph
3. MagneƟc resonance imaging
4. Cervical sagiƩal alignment
Take Home Messages
1. The C2-7 angle in the kyphoƟc group was similar between the standing
radiographs and the supine MRI images. However, the C2-7 angle in the
lordoƟcgroup was diﬀerent ,and larger in the radiographs than in the MRI
2. Neck Ɵlt was a constant parameter.
Keywords Cervical parameters · Standing radiograph · Magnetic resonance imaging · Cervical sagittal alignment
While most surgeons routinely obtain weight-bearing radio-
graphs as part of their surgical planning approach, in our
practice and at national meetings, we have found that some
surgeons still perform procedures, such as laminectomy and
Electronic supplementary material The online version of this
article (https ://doi.org/10.1007/s0058 6-018-5550-z) contains
supplementary material, which is available to authorized users.
* Masahito Oshina
Extended author information available on the last page of the article