Purpose or Case Report: To prospectively investigate the diagnostic accuracy and added value of lung MRI for evaluating pulmonary hydatid disease in children by comparing MRI findings with MDCT findings.
Methods & Materials: 28 consecutive children with clinically suspected of having pulmonary hydatid disease were enrolled in this prospective research study from October, 2012 to July, 2018. In all 28 pediatric patients (24 boys, 4 girls; mean age, 8.93 +/- 3.1 years; range, 5 to 17) were included in this study, MRI without contrast and enhanced MDCT of the chest were performed within 48 hours of each other. Two pediatric radiologists independently evaluated the lungs for the presence of consolidation, nodule, and mass (solid versus cyst). Cyst was further evaluated for the presence of fluid, air, and internal membrane. The accuracy of MRI and MDCT for detecting pulmonary hydatid disease was obtained and compared between them. Interobserver agreement was measured with the kappa coefficient.
Results: Final diagnosis of pulmonary hydatid cyst was established in 25 children. Post-surgical histopathological confirmation was available in 12/25 patients (48%), while a positive hydatid serology was confirmed in 8/25 patients (32%). Remaining five patients (20%) were diagnosed to have pulmonary hydatid cyst based on the epidemiological setting and typical radiological findings. The accuracy of MRI and MDCT for detecting pulmonary hydatid cyst was 92.86%. There was no difference between MRI and MDCT for accurately detecting pulmonary hydatid cyst (p < 0.001). Internal membranes were detected in 11/28 patients (39.28%) with MRI and 3/28 patients (10.71%) with MDCT. Almost perfect interobserver agreement was present between two independent reviewers (k = 1).

Conclusions: Lung MRI without contrast is comparable to enhanced MDCT for accurately detecting lung cyst in pediatric patients with pulmonary hydatid disease. However, MRI provides an added diagnostic value by demonstrating internal membranes which is specific to pulmonary hydatid disease.