AI Insight
This study evaluated spectral CT imaging parameters, particularly electron density (ED), for assessing lumbar intervertebral disk degeneration in 338 disks from 100 patients. The researchers found that ED differences between the annulus fibrosus and nucleus pulposus regions strongly correlated with degeneration grade and achieved high diagnostic accuracy (area under curve values of 0.92 and 0.88) for distinguishing normal from degenerative disks. Spectral CT parameters, especially electron density measurements, demonstrated potential as quantitative tools for diagnosing disk degeneration.
Why it matters
This research provides a quantitative CT-based method for evaluating disk degeneration, which could supplement or complement MRI in clinical practice. The technique may offer a more objective assessment tool for low back pain diagnosis and treatment planning, particularly when MRI is contraindicated or unavailable.
Understand the Science
by Masanori Nakajo, Tsubasa Nakano, Tomohito Hasegawa, Kiyohisa Kamimura, Koji Takumi, Hiroaki Nagano, Masatoyo Nakajo, Hiroyuki Tominaga, Mutsukazu Hayashi, Takashi Iwanaga, Fumiko Kanzaki, Eran Langzam, Graeme Campbell, Ko Higuchi, Takashi Yoshiura
Objective
This study aimed to investigate the ability of spectral CT parameters to evaluate lumbar intervertebral disk degeneration (LIDD).
Summary of background data
LIDD is the most prevalent cause of low back pain. However, the usefulness of spectral CT for LIDD evaluation remains unclear.
Methods
This retrospective study included consecutive patients who underwent spectral CT and Magnetic resonance imaging for spinal disease examination from February 2018 to June 2021 on a single center. The conventional polyenergetic 120-kVp computed tomography value (CTconv), electron density (ED), and effective atomic number (Zeff) were measured in the annulus fibrosus (AF) and nucleus pulposus (NP) in each disk. Additionally, differences in each spectral CT parameter were obtained between the anterior AF and NP and between the posterior AF and NP. These parametric values were correlated with modified Pfirrmann grade (mPG) using Spearman’s rank correlation coefficients. The receiver operating characteristic curve analysis was used to assess diagnostic performances for differentiating between normal and degenerative disks.
Results
Three hundred thirty-eight lumbar intervertebral disks of 100 patients were analyzed. The CTconv and ED were negatively correlated with mPG in AF (ρ = −0.29 to −0.36) and positively correlated with mPG in NP (ρ = 0.16–0.45), whereas Zeff in NP was negatively correlated with mPG (ρ = −0.29 to −0.38). The ED differences between the anterior AF and NP and between the posterior AF and NP were strongly correlated with mPG (ρ = −0.71 and −0.64, respectively) and demonstrated high diagnostic performances in differentiating between normal and degenerative disks (area under the receiver operating characteristic curve values = 0.92 and 0.88, respectively).
Conclusion
Spectral CT parameters, particularly ED, can diagnose lumbar intervertebral disk degeneration.
Source: Spectral CT electron density for evaluation of lumbar intervertebral disk degeneration