Ultrasonographic diagnosis of lumbar disc protrusion in adolescents: comparison with MRI results

Abstract

Degenerative changes in the discs begin already in childhood, as evidenced by histological studies. Purpose – to compare the diagnostic capabilities of US and MRI in identifying and determining the localization of protrusion of the lumbar intervertebral discs in adolescents. Materials and methods. The study involved 74 patients with protrusion of the lumbar intervertebral discs aged 17-21 years: 25 (33.8 %) girls and 39 (66.2 %) boys. All patients complained of pain in the lower back, and when examined by a neuropathologist, some clinical signs of osteochondrosis were revealed. USG of the lumbar spine was performed with a convex transducer with a frequency of 2-5 MHz at levels from L1-L2 to L5-S1 in sagittal and axial projections. MRI was performed on a Magnetom Aera 1.5T apparatus with standard research protocols. Results. According to the results of MRI at the L4-L5 level, protrusion was localized in 27 (36.5 ± 5.6%) cases, at the level of L5-S1 – in 26 (35.1 ± 5.5 %) cases – significantly (P <0, 05) more often than at the level of L3-L4, L2-L3 і L1-L2 (P <0.001), respectively. The coincidence of the results of MRI and USG took place in 72 (97.3 %) cases. In two cases of USG, the picture of L4-L5 and L5-S1 protrusion was interpreted as a hernia. According to the results of MRI, medial localization of disc protrusion was recorded in 31 (41.9 ± 5.7 %) cases, paramedial – in 29 (39.2 ± 5.7 %), and foraminal – in 14 (18.9 ± 4.5 %) cases, and with USG – in 30 (40.5 ± 5.6%), 28 (37.8 ± 5.6 %) and 14 (18.9 ± 4.5 %) cases, respectively. Strengthening of signals (or increased echogenicity) of the nucleus pulposus (NP) was detected on MRI in 61 (82.4 ± 4.4 %) cases, on USG in 56 (77.8 ± 4.9 %) cases; calcification of the NP in 32 (43.2 ± 5.8 %) and 35 (48.6 ± 5.7%); mixing of hyperechogenic NP - in 31 (41.9 ± 5.7 %) and 43 (59.7 ± 5.6%) cases (P <0.05); FR thinning – in 56 (75.7 ± 5.9 %) and 53 (73.6 ± 5.3 %) cases; decrease in the sagittal size of the spinal canal – in 17 (23.0 ± 4.9 %) and 18 (25.0 ± 5.1 %) cases, respectively.