Genki Okita1, Tetsuro Ohba2, Tomohiro Takamura3, Shigeto Ebata1, Ryo Ueda4, Hiroshi Onishi3, Hirotaka Haro1, Masaaki Hori5. 1. Department of Orthopaedic Surgery, University of Yamanashi, Yamanashi, Japan. 2. Department of Orthopaedic Surgery, University of Yamanashi, Yamanashi, Japan. Electronic address: tooba@yamanashi.ac.jp. 3. Department of Radiology, University of Yamanashi, Yamanashi, Japan. 4. Department of Radiology, School of Medicine, Juntendo University, Tokyo, Japan; Department of Radiological Science, Tokyo Metropolitan University of Health Sciences, Tokyo, Japan. 5. Department of Radiology, University of Yamanashi, Yamanashi, Japan; Department of Radiology, School of Medicine, Juntendo University, Tokyo, Japan.
Abstract
BACKGROUND CONTEXT: Surgical outcome and the severity of cervical spondylotic myelopathy (CSM) are unpredictable and cannot be estimated by conventional anatomical magnetic resonance imaging (MRI). The utility of diffusion tensor imaging (DTI) to quantify the severity of CSM and to assess postoperative neurologic recovery has been investigated. However, whether conventional DTI should be applied in a clinical setting remains controversial. Neurite orientation dispersion and density imaging (NODDI) is a recently introduced model-based diffusion-weighted MRI technique that quantifies specific microstructural features related directly to neuronal morphology. However, there are as yet few clinical applications of NODDI reported. Indeed, there are no reports to indicate NODDI is useful for diagnosing CSM. STUDY DESIGN: This is a retrospective cohort study using consecutive patients. PURPOSE: The objective of this study was to evaluate the utility of NODDI and conventional DTI for detecting changes in the spinal cord microstructure. In particular, this study aimed to quantify the preoperative severity of CSM and to assess postoperative neurologic recovery from this myelopathy. PATIENT SAMPLE: We included 27 consecutive patients with a nontraumatic cervical lesion from CSM who underwent laminoplasty at a single institution between April 2012 and April 2015. The patients underwent MRI before and approximately 2 weeks after surgery. OUTCOME MEASURES: In addition to conventional DTI metrics, we evaluated the intracellular volume fraction (ICVF) and the orientation dispersion index (ODI), which are metrics derived from NODDI. The 10-second grip and release test and the Japanese Orthopaedic Association scoring system were used before and 1 year after surgery to assess neurologic outcome. MATERIALS AND METHODS: Neurite orientation dispersion and density imaging and conventional DTI values were measured at the C2-C3 intervertebral level (control value) and at the most compressed levels (C3-C7 intervertebral levels) were measured. The changes in these values pre- and postoperative were demonstrated. Correlations between NODDI and conventional DTI values and clinical outcome were determined. RESULTS: Preoperative fractional anisotropy was significantly correlated with the severity of neural damage, but not with postoperative neurologic recovery. No significant correlation could be found between the preoperative ICVF, the ODI, the apparent diffusion coefficient, and the severity of the preoperative neurologic dysfunction. Preoperative ICVF was most strongly correlated with the severity of neurologic dysfunction and postoperative neurologic recovery. CONCLUSIONS: Conventional DTI may be applied clinically to assess the severity of myelopathy. Neurite orientation dispersion and density imaging may be more valuable than conventional DTI to predict outcome following surgery in patients with CSM.
BACKGROUND CONTEXT: Surgical outcome and the severity of cervical spondylotic myelopathy (CSM) are unpredictable and cannot be estimated by conventional anatomical magnetic resonance imaging (MRI). The utility of diffusion tensor imaging (DTI) to quantify the severity of CSM and to assess postoperative neurologic recovery has been investigated. However, whether conventional DTI should be applied in a clinical setting remains controversial. Neurite orientation dispersion and density imaging (NODDI) is a recently introduced model-based diffusion-weighted MRI technique that quantifies specific microstructural features related directly to neuronal morphology. However, there are as yet few clinical applications of NODDI reported. Indeed, there are no reports to indicate NODDI is useful for diagnosing CSM. STUDY DESIGN: This is a retrospective cohort study using consecutive patients. PURPOSE: The objective of this study was to evaluate the utility of NODDI and conventional DTI for detecting changes in the spinal cord microstructure. In particular, this study aimed to quantify the preoperative severity of CSM and to assess postoperative neurologic recovery from this myelopathy. PATIENT SAMPLE: We included 27 consecutive patients with a nontraumatic cervical lesion from CSM who underwent laminoplasty at a single institution between April 2012 and April 2015. The patients underwent MRI before and approximately 2 weeks after surgery. OUTCOME MEASURES: In addition to conventional DTI metrics, we evaluated the intracellular volume fraction (ICVF) and the orientation dispersion index (ODI), which are metrics derived from NODDI. The 10-second grip and release test and the Japanese Orthopaedic Association scoring system were used before and 1 year after surgery to assess neurologic outcome. MATERIALS AND METHODS: Neurite orientation dispersion and density imaging and conventional DTI values were measured at the C2-C3 intervertebral level (control value) and at the most compressed levels (C3-C7 intervertebral levels) were measured. The changes in these values pre- and postoperative were demonstrated. Correlations between NODDI and conventional DTI values and clinical outcome were determined. RESULTS: Preoperative fractional anisotropy was significantly correlated with the severity of neural damage, but not with postoperative neurologic recovery. No significant correlation could be found between the preoperative ICVF, the ODI, the apparent diffusion coefficient, and the severity of the preoperative neurologic dysfunction. Preoperative ICVF was most strongly correlated with the severity of neurologic dysfunction and postoperative neurologic recovery. CONCLUSIONS: Conventional DTI may be applied clinically to assess the severity of myelopathy. Neurite orientation dispersion and density imaging may be more valuable than conventional DTI to predict outcome following surgery in patients with CSM.
Authors: Jan Valošek; Petr Bednařík; Miloš Keřkovský; Petr Hluštík; Josef Bednařík; Alena Svatkova Journal: J Clin Med Date: 2022-04-20 Impact factor: 4.964
Authors: Allan R Martin; Lindsay Tetreault; Aria Nouri; Armin Curt; Patrick Freund; Vafa Rahimi-Movaghar; Jefferson R Wilson; Michael G Fehlings; Brian K Kwon; James S Harrop; Benjamin M Davies; Mark R N Kotter; James D Guest; Bizhan Aarabi; Shekar N Kurpad Journal: Global Spine J Date: 2021-11-19
Authors: Gergely David; Siawoosh Mohammadi; Allan R Martin; Julien Cohen-Adad; Nikolaus Weiskopf; Alan Thompson; Patrick Freund Journal: Nat Rev Neurol Date: 2019-10-31 Impact factor: 42.937