The clinical value of three-dimensional measurement in the diagnosis of thoracic myelopathy caused by ossification of the ligamentum flavum

Abstract

Background: Thoracic ossification of the ligamentum flavum (OLF) is a major cause of thoracic myelopathy, which is often accompanied by multiple segmental stenosis or other degenerative spinal diseases.However, in the above situations, it is difficult to determine the exact segment responsible. The objective of this study was to analyze three-dimensional (3D) radiological parameters in order to establish a novel diagnostic method for discriminating the responsible segment in OLF-induced thoracic myelopathy, and to evaluate its superiority compared to the conventional diagnostic methods.Methods: Eighty-one patients who underwent surgery for thoracic myelopathy caused by OLF from 2016 to 2020 were enrolled in this study as the myelopathy group, and 79 patients who had thoracic OLF but displayed no definite neurological signs from 2018 to 2020 were enrolled as the non-myelopathy group. We measured the one-dimensional (1D), two-dimensional (2D), and 3D radiological parameters, calculated their optimal cutoff values, and compared their diagnostic values.Results: Significant differences were observed in the 1D, 2D, and 3D radiological parameters between the myelopathy and non-myelopathy groups (P<0.01). As a 3D radiological parameter, the OLF volume (OLFV) ratio (OLFV ratio = OLFV/normal canal volume × 100%) was the most accurate parameter for diagnosing OLF-induced thoracic myelopathy, with a diagnostic coincidence rate of 88.1%. We also found that an OLFV ratio of 26.3% could be used as the optimal cutoff value, with a sensitivity of 87.7% and a specificity of 88.6%. Moreover, the OLFV ratio [area under the curve (AUC): 0.92, 95% confidence interval (CI): 0.86-0.95] showed a statistically higher diagnostic value than the 1D and 2D parameters (AUC: 0.75, 95% CI: 0.67-0.81; AUC: 0.84, 95% CI: 0.77-0.89, respectively) (P<0.05). Pearson correlation analysis illustrated that the OLFV ratio was significantly negatively correlated with preoperative modified Japanese Orthopedic Association (mJOA) score (r=-0.73, 95% CI: -0.81 to -0.60, P<0.01). Conclusions:Our results demonstrate the superiority of the OLFV ratio over the conventional 1D and 2D computed tomography (CT)-based radiological parameters for the diagnosis of OLF-induced thoracic myelopathy. The novel diagnostic method based on the OLFV ratio will help to determine the responsible segment in multi-segmental thoracic OLF or when thoracic OLF coexists with other degenerative spinal diseases. The OLFV ratio also accurately reflects the clinical state of symptomatic patients with thoracic OLF.

Three-dimensional measurement and analysis of morphological parameters of the uterus in infertile women

“…None of the ASRM, ESHRE-ESGE, or Congenital Uterine Malformation by Experts (CUME) has provided detailed descriptions of normal and arcuate uterus. The 3D morphological parameters can diagnose the thoracic myelopathy resulting from thoracic ossification of the ligamentum flavum more accurately than 2D morphological parameters (18). This study found that ECL, EVM, EVL, ESM, and ESL were significantly lower in arcuate uterus compared to normal uterus using the 3D measurement approach.…”

Three-dimensional imaging analysis for the diagnosis of dural ossification in thoracic ossification of the ligamentum flavum: a multicenter study

“…However, it is difficult to simultaneously assess the severity and range of compression based only on the 1D or 2D radiological parameters (14,21). Our previous study found that the 3D OR could precisely reflect the oppressive state of OLF from multiple dimensions and thus predict the clinical grade of thoracic myelopathy (14). Herein, we introduce the 3D OR to test this hypothesis and report whether it could be used as an indicator to identify DO in patients with OLF.…”

“…In this study, we first proposed that the formation of DO was associated with the severity of OLF compression of the dura mater and the contact area of the OLF and the dura mater. However, it is difficult to simultaneously assess the severity and range of compression based only on the 1D or 2D radiological parameters (14,21). Our previous study found that the 3D OR could precisely reflect the oppressive state of OLF from multiple dimensions and thus predict the clinical grade of thoracic myelopathy (14).…”

“…Radiological studies regarding OLF-DO are relatively rare, and the diagnostic accuracy of imaging signs still needs to be improved (11,12). Furthermore, there are variations in how the slices through tissues are obtained based on the spinal curvature, especially for the upper or middle thoracic spine, which might lead to deviations in the results of conventional measurement methods (13)(14)(15)(16). Therefore, most of the current findings can only be applied to the lower thoracic spine, despite nearly 50% of DOs being located in the upper and middle segments (9,12,14,15).…”

“…Therefore, we speculate that the formation of DO is associated with the severity of OLF compression of the dura mater and the contact area of the OLF and the dura mater. Considering that OLF compression is not a 2-dimensional (2D) problem and is rather a 3D problem (14,21,22), a novel 3D imaging analysis based on CT scans was used in the present study. This may correct the measurement deviation caused by spinal curvature with multiplanar reconstruction (MPR).…”