Sarcoidosis in children: HRCT findings and correlation with pulmonary function tests

Rationale: High-resolution computed tomography (HRCT) plays an important role in the diagnosis and staging of pulmonary sarcoidosis, but implies radiation exposure. In this light, we aimed to describe HRCT findings as well as their relationship with pulmonary function tests (PFT) in children with pulmonary sarcoidosis.

Methods: In a retrospective study, 18 pediatric patients with sarcoidosis, including 12 with pulmonary abnormalities (PA group) and 6 without pulmonary abnormalities (APA group) were followed over a 16-year period. Relationships between HRCT scores and PFT were studied by non-parametric Spearman's test at diagnosis and by restricted maximum likelihood (REML) analysis during follow-up.

Results: Forty-three HRCT were scored. Twelve patients showed abnormal HRCT findings at diagnosis with multiple nodules or micronodules, while ground-glass opacities were seen in 11 patients. Ten patients exhibited pleural thickening or thickening of the fissure and 6 had interlobular septal thickening at diagnosis. No correlation between HRCT and forced vital capacity (FVC), forced expiratory volume in 1 sec (FEV1), forced expiratory flow during the mid-half of the FVC (FEF(25-75)) and specific dynamical compliance (SpecC(Ldyn)) was found at diagnosis. However, linear mixed models showed that changes in total HRCT scores over time were significantly associated with SpecC(Ldyn), FVC, and FEV1 modifications.

Conclusion: Radiologic findings in children with pulmonary sarcoidosis were similar to those in adults. HRCT and PFT are both essential investigations at diagnosis; however, the correlation between HRCT pulmonary parenchymal findings and PFT over time suggests the possibility of reducing the number of HRCT during follow-up to decrease unnecessary radiation exposure.