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MRI Findings of Infectious Sacroiliitis in Children: Are There Age-Dependent Differences?
Sara A Cohen1,2, David M Biko2,3, Summer L Kaplan2,3
1Department of Radiology, Cornell University, Ithaca, NY.
Insights
Infectious sacroiliitis MRI findings are common in children. Younger children show significantly more posterior extracapsular edema, indicating age-related differences in this pediatric condition.
Area of Science:
- Pediatric Radiology
- Infectious Diseases
- Musculoskeletal Imaging
Background:
- Infectious sacroiliitis is a serious condition in children.
- MRI is crucial for diagnosing pediatric infectious sacroiliitis.
- Understanding age-specific MRI findings aids diagnosis and management.
Purpose of the Study:
- To determine the prevalence of MRI findings in pediatric infectious sacroiliitis.
- To analyze age-related differences in MRI findings.
- To compare MRI with pelvic radiographs for diagnosis.
Main Methods:
- Retrospective review of MRI examinations in children with infectious sacroiliitis (2002-2018).
- Two blinded radiologists assessed MRI for marrow edema, erosions, capsular bulge, extracapsular edema, and abscess.
- Comparison of findings between younger (<5 years) and older (≥8 years) children using statistical tests.
Main Results:
- Periarticular marrow edema and anterior extracapsular edema were universal.
- Posterior extracapsular edema was significantly more common in younger children (p=0.01).
- No significant age differences in erosions, capsular bulge, or abscess were observed. Pelvic radiographs had 50% diagnostic accuracy.
Conclusions:
- MRI reveals common findings in pediatric infectious sacroiliitis across all ages.
- Posterior extracapsular edema is a key finding more prevalent in younger children.
- MRI is superior to radiographs for evaluating infectious sacroiliitis in children.
Abstract:
OBJECTIVE. The purpose of this study was to investigate the prevalence of various MRI findings of infectious sacroiliitis in children and with respect to age. MATERIALS AND METHODS. This institutional review board-approved, HIPAA-compliant retrospective study included children with infectious sacroiliitis who underwent MRI examination between December 1, 2002, and September 30, 2018. Two radiologists blinded to the clinical outcome reviewed each MRI examination to determine the presence or absence of periarticular marrow edema, erosions, capsular bulge, extracapsular edema, and soft-tissue abscess. If available, pelvic radiographs were retrospectively reviewed by a third radiologist. Mann-Whitney U, chi-square, and Fisher exact tests were used to compare MRI findings between younger and older children. RESULTS. The study included 40 children (19 boys and 21 girls; mean age, 8.6 ± 6.2 [SD] years). Sixteen children presented at or below 5 years of age (mean age, 1.7 ± 1.4 years) and 24 children presented at or above 8 years of age (mean age, 13.3 + 2.6 years). Periarticular marrow edema and anterior extracapsular edema were present in all children. Posterior extracapsular edema (p = 0.01) was statistically significantly more common in younger children when compared with older children. There was no significant difference in the presence of erosions (p = 0.60), capsule bulge (p = 0.63), or abscess (p = 0.34) between younger and older children. Pelvic radiographs (n = 28; obtained 1.6 days ± 1.7 from MRI) allowed the correct identification of the abnormal joint in only 50% of the studies. CONCLUSION. MRI findings of infectious sacroiliitis are common in children of all ages with posterior extracapsular edema statistically significantly more prevalent in younger children.
