Magnetic resonance spectroscopy (1H) of the intervertebral lumbar disc in the adult and its application in the imaging routine

• Autor(a) principal: Cruz Maurício, J.
• Data de Publicação: 2022
• Outros Autores: Ribeiro, Maria Margarida
• Tipo de documento: Artigo
• Idioma: por
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: https://doi.org/10.25758/set.1124
• topic: Espetroscopia (1H); Discos intervertebrais lombares; Involução; Degenerescência discal; (1H) Spectroscopy; Lumbar intervertebral discs; Involution; Disc degeneration

Aims – To show the potential of magnetic resonance spectroscopy (1H-MRS) in the diagnosis of degenerative disease of the lumbar disc and to advocate the addition of this technique in the classification of the invertebral disc involution vs degeneration (L4-L5 and L5-S1) in the clinical routine of lumbar pain status, not related with mechanic causes. Material and method – We studied 102 out of 123 lumbar intervertebral discs. The distribution among spaces was 61 discs at L4-L5, 41 at the L5-S1 level, and 34 at the D12-L1 level. The magnetic resonance studies were performed using a 1.5 T scanner. A single-voxel Point Resolved Spectra Selection (PRESS) technique was used. The ratios [Lac/Nacetyl], [Nacetyl/(Lac+Lip)], and additionally the resonance of lipids were applied to evaluate the biochemistry of the discs, their involution, disc disruption, and eventual susceptibility to initiating the degeneration process. The ratios and the lipidic value of L4-L5-S1 discs were ascertained with the different behavior of D12-L1. Furthermore, the comparison between L4-L5, L5-S1, and D12-L1 discs was performed according to a rating in T2 weighted (adjusted scale 1-4 from Pfirrmann1 criteria). Results – Related to D12-L1, the ratios and the lipids of L4-L5-S1 discs are statistically different. When used as a complementary of conventional T2 weighted, they have good discrimination in all degrees of disc involution vs degeneration. The ratio [Lac/Nacetyl] at L4-L5-S1 level was increased when compared to D12-L1 (p=0.033 for disks with [1+2] score of involution and p=0.004 for disks with score [3+4]). These results suggest that disc degeneration vs involution in higher degrees defines a decrease in the lactate’s peak. The ratio [Nacetyl/(Lac+Lip)] provides good discrimination of involution between scores [1+2] and [3+4] at the L4-L5 level, presenting the values of the ratios (mean 0.65 and 0.5 with p=0.04). The mean ratio of [Nacetyl/(Lac+Lip)] in the L4-L5 disc was 1.8 times higher than that of L1-D12. The lipid spectrum at L4-L5-S1 in the higher scores showed no constant prevalence in the resonance frequencies. Conclusion – The (1H) spectroscopy of intervertebral discs may contribute with a supplementary semiology to the conventional MRI. The resonances of L4-L5 and L5-S1 discs, involuted or degenerated, must be related to D12-L1, which are more stable and have a lower likelihood of disc degeneration.