Commentary on “Coronal imbalance and intervertebral disc degeneration in degenerative scoliosis: an analysis using Hounsfield units measurement”

Dear Editor, We read with great interest the recent article by Lu et al[1], which examined the relationship between coronal imbalance and intervertebral disc degeneration in degenerative scoliosis using Hounsfield unit (HU) measurements. The study is clinically relevant because it introduces a quantitative imaging parameter into an area where assessment still relies largely on semiquantitative grading. One aspect that deserves further discussion is how disc HU should be interpreted biologically and clinically. In the vertebral-body apex subgroup, HU values varied significantly across coronal balance patterns, whereas total Pfirrmann grades did not[1]. This discrepancy is intriguing, but it also suggests that HU may not simply function as a direct surrogate for degeneration severity. computed tomography (CT) attenuation reflects tissue radiodensity, whereas disc degeneration involves a broader spectrum of changes, including water loss, proteoglycan depletion, annular disorganization, and endplate alteration[2–5]. Accordingly, HU may capture one dimension of disc change without fully corresponding to magnetic resonance imaging (MRI)-defined degenerative stages[3–5]. From a clinical perspective, the value of this approach would be clearer if the incremental contribution of HU beyond Pfirrmann grading were more explicitly defined. Disc-level analyses comparing HU categories with MRI grades, or testing how well HU distinguishes more advanced degeneration, could help determine whether HU is best regarded as a complementary biomarker rather than a substitute for established MRI assessment[2–4]. Such clarification matters because the divergence between HU and Pfirrmann findings may indicate greater sensitivity of HU to certain tissue changes, but it may also reflect that the two measures describe related yet nonidentical pathological features[1,3,4]. A clearer framework for HU standardization would also strengthen reproducibility. Because CT attenuation is influenced by acquisition and reconstruction parameters, more detailed guidance on disc-level HU measurement across scanners and centers would help future studies move toward clinically meaningful thresholds[5]. In summary, Lu et al[1] should be commended for broadening imaging assessment in degenerative scoliosis beyond conventional qualitative evaluation. Further clarification of the biological meaning of disc HU and its role alongside MRI-based grading would improve the interpretability and clinical utility of this promising method Sincerely.