Diagnostic accuracy of imaging studies in congenital lung malformations

Although fetal ultrasound, fetal MRI and postnatal CT are now widely used in the evaluation of congenital lung malformations (CLM), their diagnostic accuracy remains undefined.

To correlate prenatal and postnatal imaging studies with pathological data after CLM resection.

Retrospective, descriptive case series study.

A North American tertiary care centre.

One hundred and three consecutive lung resections for a suspected CLM between 1 January 2005 and 31 December 2015.

Diagnostic accuracy of imaging diagnosis compared with pathological evaluation.

Pathological diagnoses included congenital pulmonary airway malformation ((CPAM) n=45, 44%), bronchopulmonary sequestration (BPS; n=25, 24%), CPAM/BPS hybrid lesions (n=22, 21%) and pleuropulmonary blastoma (n=2, 2%). Fetal ultrasound detected 85 (82.5%) lesions and correctly diagnosed whether or not a lesion was a CPAM in 75% of cases (sensitivity 93%, specificity 32%). Fetal MRI had a similar concordance rate (73%) but was superior in correctly determining whether a systemic feeding vessel was present in 80% of cases (sensitivity 71%, specificity 88%) compared with an ultrasound accuracy rate of 72% (sensitivity 49%, specificity 93%). By comparison, postnatal CT correctly diagnosed whether a CPAM was present in 84% of cases (sensitivity 86%, specificity 77%) and whether a systemic feeding vessel was present in 90% of cases (sensitivity 92%, specificity 88%).

Fetal ultrasound remains an important tool in the detection and evaluation of congenital lung malformations. However, it does not correctly predict histology in approximately 25% of prenatally detected CLMs and remains limited by relatively poor sensitivity for systemic feeding vessels pathognomic for a bronchopulmonary sequestration. These data suggest the importance of obtaining additional cross-sectional imaging, preferably a postnatal CT scan, in all patients to help counsel families and to guide in the optimal management of these lesions.