The Correlation between Follow-up MRI Findings and Laboratory Results in Pyogenic Spondylodiscitis

Abstract

<jats:title>Abstract</jats:title> <jats:p>Background Although MRI is the gold-standard imaging method in the diagnosis of spondylodiscitis, role of follow-up imaging is debated and there can be discrepancies with regard to the significance of bony or soft tissue responses to treatment. Purpose of our study is to test whether the MRI changes on follow-up imaging correlate with laboratory findings of treatment response. Methods A total of 48 patients with pyogenic spondylodiscitis who underwent baseline and follow-up MRI were retrospectively reviewed. The extent of bone marrow edema, paravertebral soft tissue inflammation, and disc height were compared on baseline and follow-up MRIs with the C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) levels obtained from the medical records at baseline and on follow-up. Relationships between the MRI and laboratory changes were analyzed using the Spearmann correlation test. Results The mean MRI follow-up period was 42.25 days. Based on the CRP (resolved: n=19, resolving: n=19, and aggravated: n=10), there was significant correlation between the laboratory results and the changes in the bone and soft tissues (p &lt; 0.01, both). The correlation was best with soft tissue changes (rho: 0.48) followed by bony changes (rho: 0.41). Based on the ESR (resolved: n=8, resolving: n=22, and worsened: n=18), the correlation was stronger with bone changes (rho: 0.45, p &lt; 0.01) than it was with soft tissue changes (rho: 0.39, p = 0.01). Conclusion Follow-up MRI findings of pyogenic spondylodiscitis show variable tissue responses. CRP was best correlated with soft tissue changes, while ESR showed the best association with bony changes.</jats:p>

Amoxicillin did not Reduce Modic Change Oedema in Patients with Chronic Low Back pain - subgroup Analyses of a Randomised Trial (the AIM study)

“…There is a lack of trials evaluating the effects of antibiotics on bone edema in patients with verified low-grade bacterial disk infections. Bone edema due to infectious spondylodiscitis may persist and even increase during the first 1 to 4 months after treatment initiation 28–32. The edema may persist for years, but usually subsides within 4 to 9 months 33–35.…”

“…Bone edema due to infectious spondylodiscitis may persist and even increase during the first 1 to 4 months after treatment initiation. [28][29][30][31][32] The edema may persist for years, but usually subsides within 4 to 9 months. [33][34][35] In a study by Zarrouk et al, 35 edema persisted in 75% of patients at 3 months and 15% at 6 months.…”

“…Euba et al 33 found bone edema in 70% of patients at a median of six months after the end of treatment. These studies [28][29][30][31][32][33][34] involved patients referred by clinicians for follow-up MRI. Those not referred (68%-84% in two samples) 30,33 may have been less likely to have persistent edema.…”