Abstract
Cartilage endplate (CEP) biochemical composition may influence disc degeneration and regeneration. However, evaluating CEP composition in patients remains a challenge. We used T2* mapping from ultrashort echo‐time (UTE) magnetic resonance imaging (MRI), which is sensitive to CEP hydration, to investigate spatial variations in CEP T2* values and to determine how CEP T2* values correlate with adjacent disc degeneration. Thirteen human cadavers (56.4 ± 12.7 years) and seven volunteers (36.9 ± 10.9 years) underwent 3T MRI, including UTE and T1ρ mapping sequences. Spatial mappings of T2* values in L4‐S1 CEPs were generated from UTE images and compared between subregions. In the abutting discs, mean T1ρ values in the nucleus pulposus were compared between CEPs with high vs low T2* values. To assess in vivo repeatability, precision errors in mean T2* values, and intraclass correlation coefficients (ICC) were measured from repeat scans. Results showed that CEP T2* values were highest centrally and lowest posteriorly. In the youngest individuals (<50 years), who had mild‐to‐moderately degenerated Pfirrmann grade II‐III discs, low CEP T2* values associated with severer disc degeneration: T1ρ values were 26.7% lower in subjects with low CEP T2* values (P = .025). In older individuals, CEP T2* values did not associate with disc degeneration (P = .39‐.62). Precision errors in T2* ranged from 1.7 to 2.6 ms, and reliability was good‐to‐excellent (ICC = 0.89‐0.94). These findings suggest that deficits in CEP composition, as indicated by low T2* values, associate with severer disc degeneration during the mild‐to‐moderate stages. Measuring CEP T2* values with UTE MRI may clarify the role of CEP composition in patients with mild‐to‐moderate disc degeneration.
Highlights
The biochemical composition of the cartilage endplate (CEP) is believed to be a key factor that influences intervertebral disc health
We quantified the in vivo repeatability of CEP T2* measurements to gauge the clinical feasibility of using T2* values to noninvasively assess CEP composition
Since the individuals in the youngest age group had mild‐to‐moderately degenerated Pfirrmann grade II to III discs, our findings suggest that deficits in CEP composition, as indicated by low T2* values, are associated with more severe disc degeneration during the mild‐to‐moderate stages
Summary
The biochemical composition of the cartilage endplate (CEP) is believed to be a key factor that influences intervertebral disc health. Nutrients entering the avascular disc and exiting metabolites must pass through the CEP,[1] and deficits in CEP composition that result in lower water content or porosity, such as fibrosis or calcification, can block solute passage. This could hinder disc cell survival and function[2] as well as limit the success of disc regenerative therapies that increase nutrient demands.[3,4] despite the theoretical importance of CEP biochemical composition, little is known about how CEP composition varies spatially within or between individuals. T1ρ values are positively correlated with the GAG and water contents of the NP,[14] and T1ρ assessment is sensitive to NP biochemical changes that typify early disc degeneration.[15,16] Last, we quantified the in vivo repeatability of CEP T2* measurements to gauge the clinical feasibility of using T2* values to noninvasively assess CEP composition
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
