Correlation and differences in cervical sagittal alignment parameters between cervical radiographs and magnetic resonance images
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 radiographs and supine MRI images, and assess whether neck position affects the cervical parameters and neurological changes.
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.
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 different 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).
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 recommend that standing cervical radiographs should be preoperatively obtained for all surgical patients.
KeywordsCervical parameters Standing radiograph Magnetic resonance imaging Cervical sagittal alignment
Compliance with ethical standards
Conflict of interest
No funds were received in support of this work. Dr. Riew receives royalties from Biomet and Medtronic, owns stock in Osprey, Expanding Orthopedics, Spineology, Spinal Kinetics, Nexgen Spine, Amedica, Vertiflex, Benvenue, Paradigm Spine, receives honorarium from Biomet, Medtronic, Zeiss, and AO Spine. Dr. Sakae Tanaka receives honorarium from MSD K.K, ASAHI KASEI PHARMA CORPORATION, Astellas Pharma Inc, Eisai Co., Ltd, KAKEN PHARMACEUTICAL CO.LTD, Johnson & Johnson K. K, DAIICHI SANKYO COMPANY LIMITED, Taisho Toyama Pharmaceutical Co., Ltd, Mitsubishi Tanabe Pharma Corporation, Chugai Pharmaceutical Co., Ltd, Eli Lilly Japan K. K, Pfizer Japan inc, TEIJIN PHARMA LIMITED, AbbVie GK, ONO PHARMACEUTICAL CO., LTD, Amgen Astellas BioPharma K. K, Amgen inc, KYOCERA Medical Corporation, receives endowments from AYUMI Pharmaceutical Corporation, Bristol-Myers Squibb, Pfizer Japan inc, DAIICHI SANKYO COMPANY LIMITED, Chugai Pharmaceutical Co., Ltd, and receives grants from The Japan Agency for Medical Research and Development (AMED), Japan Society for the Promotion of Science (JSPS)/Grant-in-Aid for Scientific Research (A), and Japan Society for the Promotion of Science (JSPS)/Grant-in-Aid for Exploratory Research. Dr. Oshina, Dr. Oshima, and Dr. Masashi Tanaka have nothing to disclose.
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