Kayvan Keshari BS, Presenter: Nothing to Disclose

Thomas Marc Link MD, Abstract Co-Author: Research grant, GlaxoSmithKline plc, Brentford, UK Research grant, Merck & Co, Inc, Whitehouse Station, NJ

Jeffrey Lotz PhD, Abstract Co-Author: Nothing to Disclose

Serena Hu MD, Abstract Co-Author: Nothing to Disclose

John Kurhanewicz PhD, Abstract Co-Author: Nothing to Disclose

Sharmila Majumdar PhD, Abstract Co-Author: Nothing to Disclose

Conventional MR imaging methods of assessing the painful, degenerated intervertebral disc focus on morphologic criteria. However, it is well known that there is a poor correlation between morphologic findings and patient symptoms. The purpose of this preliminary study was to utilize quantitative high-resolution magic angle spinning (HR-MAS) NMR spectroscopy to characterize biochemical markers in surgically removed disc specimens from patients with painful disc degeneration and a reference population, consisting of patients with scoliosis.

Disc tissue removed at surgery in age-matched patients with discogenic pain (n=9) and patients with scoliosis undergoing anterior spinal fusion (n=9) was studied using HR-MAS at 11.7T, 1°C, and a 2,250Hz spin rate on a Varian INOVA spectrometer. Quantitative proton spectra were acquired for tissue samples with a mean weight of 14.28 ± 2.91 mg. A spin-echo rotor-synchronized Carr-Purcell-Meiboom-Gill (CPMG) pulse sequence was used for acquisition. The lactate resonance (1.31 ppm), n-Acetyl resonance associated with proteoglycans (PG, 2.04 ppm), and collagen breakdown region (col, 3.30-4.00 ppm) were analyzed to compare disc specimens.

Spectral analysis showed lower ratios of PG/col (0.46 ± 0.24) content and PG/Lactate (0.31±0.22) in specimens obtained from discogenic pain patients while in the specimens of patients with scoliosis the ratios of PG/col (0.77 ± 0.48) and PG/Lactate (2.24 ± 1.11) were significantly higher (p<0.001). The ratios of Lactate/col were significantly higher (0.77 ± 0.48) in discogenic pain versus (0.40 ± 0.21) scoliosis patients (p<0.05).

Our results suggest that biochemical markers may characterize processes that correlate with discogenic pain. We hypothesize that low pH due to increased lactate, may stimulate nerve fibers in degenerated painful discs.

This method can be used to not only characterize surgical samples, but allows for the potential of using in vivo MR spectroscopic imaging to diagnosis discogenic back pain.

Keshari, K, Link, T, Lotz, J, Hu, S, Kurhanewicz, J, Majumdar, S, Potential MR Spectroscopic Biochemical Markers to Diagnose Discogenic Back Pain.  Radiological Society of North America 2006 Scientific Assembly and Annual Meeting, November 26 - December 1, 2006 ,Chicago IL. http://archive.rsna.org/2006/4441660.html