Imaging Diagnosis for Intradiaphragmatic Pulmonary Sequestration: A Pilot Study.

Abstract

Extrapulmonary sequestration (EPS) within the diaphragm (ID-EPS) is rare and requires additional procedures such as incision or detachment of the diaphragm from the lesion for diagnosis. This study aimed to describe the imaging findings and evaluate the diagnostic accuracy of ultrasonography and computed tomography (CT) for ID-EPS. Split diaphragm sign, shape of lesion edge, drainage vein into intra-abdomen on ultrasound and CT, and lesion characteristics on ultrasound were compared between patients with ID-EPS and with above-diaphragm EPS (AD-EPS) using Fisher's exact test. Three and nine patients were diagnosed with ID-EPS and AD-EPS, respectively. Significant differences were observed between the two groups in the split diaphragm sign on ultrasound (presence/absence in patients with ID-EPS vs AD-EPS, 2/1 vs 0/9, P = .046), shape of lesion edge on ultrasound/CT (round/beak in patients with ID-EPS vs AD-EPS, 3/0 vs 0/9, P = .005 on both CT and ultrasound), lesion characteristics on ultrasound (presence/absence of cystic area within lesion in patients with ID-EPS vs AD-EPS, 0/3 vs 7/2, P = .046), and the drainage vein into the abdomen on CT (presence/absence in patients with ID-EPS vs AD-EPS; 2/1 vs 0/9, P = .046). No drainage veins were visualized in the abdomen on ultrasonography and no significant differences in the presence/absence of the split-diagram sign on CT (presence/absence in patients with ID-EPS vs AD-EPS and ID-EPS; 0/3 vs 0/9, P > .999; 1/2 vs 0/9, P = .250) were observed between the two groups. A combination of postnatal ultrasonography and CT was useful in predicting EPS located within the diaphragm.