Paravertebral soft tissue swelling on magnetic resonance images helps in differentiation between osteoporotic and malignant vertebral fractures.

BACKGROUND

Osteoporotic vertebral fracture (OVF) is one of the most common sequelae of osteoporosis. Differential diagnosis between OVF and malignant vertebral fracture (MVF) is a challenge in clinical practice. Findings on computed tomography and magnetic resonance images (MRI) may help to differentiate between these two types of fracture.

AIM: To determine whether paravertebral soft tissue swelling is useful for differentiation between OVF and MVF.

METHODS

We retrospectively reviewed the MRI for 165 patients diagnosed with a vertebral fracture between May 2021 and July 2022. Three radiologists evaluated the vertebral segments and thickness of soft tissue swelling on sagittal MRI by consensus. The morphology of the soft tissue swelling was also evaluated. The statistical analyses were performed using the χ 2 test and analysis of variance.

RESULTS

The study included 117 patients (153 vertebrae) with OVF and 48 patients (63 vertebrae) with MVF. Soft tissue swelling was observed beneath the anterior longitudinal ligament on sagittal MRI and rim-shaped in the paravertebral area on axial MRI in all 153 vertebrae with OVF (100%) and in 12 (19%) of the 63 vertebra with MVF; the difference was statistically significant (P < 0.001), 95%CI: 3.156-8.735. Soft tissue swelling beneath the anterior longitudinal ligament spanned significantly more vertebral segments in patients with OVF than in those with MVF (P < 0.001), 95%CI: 0.932-1.546. The mean thickness of the soft tissue swelling was significantly greater for OVF than for MVF (5.62 mm ± 2.50 mm vs 3.88 mm ± 1.73 mm, P < 0.05, 95%CI: 0.681-0.920). Post-contrast examination was performed in 13 patients; T1-weighted images confirmed OVF in 11 cases and MVF in 2 cases. Soft tissue swelling in OVF and MVF had a fusiform appearance or appeared as a thin line on sagittal MRI and was rim-shaped on axial MRI. The length and diameter of the soft tissue swelling in patients with OVF decreased during follow-up.

CONCLUSION

Paravertebral soft tissue swelling is helpful for differentiating between OVF and MVF.