Ann Michelle Johnson MD, Presenter: Nothing to Disclose

Beverly Gilbert Coleman MD, Abstract Co-Author: Consultant, Koninklijke Philips Electronics NV

Sandra S. Kramer, Abstract Co-Author: Nothing to Disclose

Portia Kreiger MD, Abstract Co-Author: Nothing to Disclose

R. Douglas Wilson, Abstract Co-Author: Nothing to Disclose

Evaluate features of non-macrocystic lung lesions on fetal MRI (MR) and correlate with prenatal ultrasound (US) and postnatal computed tomography (CT) to aid in predicting final pathology.

Retrospective review of 486 fetal MRs from 6/00-11/05 for evaluation of primary chest lesion was performed. 55 cases with US and CT met study criteria: 1) homogeneous lung lesion with few or no macrocysts on MR, and 2) pathology data available. Location, size, and presence of cysts/systemic vessels were analyzed and correlated with pathology. Pathology features evaluated were hyperexpansion, mucostasis/mucocele, maldevelopment (i.e. features of cystic adenomatoid malformation (CCAM)), and systemic vessels.

Median gestational age was 23 weeks, range 18-32 weeks. US was available in 52/55; CT in 48/55. Final pathology included: Congenital lobar emphysema (CLE)=1, CLE with features of bronchial atresia (BA)=2, BA=12, BA with small cyst CCAM=22, small cyst CCAM with features of BA=15, large cyst CCAM=3, and fetal CCAM=3. Two lobes with different pathology were found in 3 cases. 17 cases had associated sequestration (BPS), all detected prenatally; 11/17 cases had features of BA, small cyst CCAM, and BPS. Mucocele, typical of obstruction, was seen in 23 cases of BA: 13/23 had a central cyst or tubular structure on MR; 17/23 had a debris-filled airway on CT. 14/42 cases with maldevelopment had cysts on pre- or postnatal studies. 3 cases with features of CLE had very homogeneous signal with branching lung vessels. 3 cases of large cyst CCAM had several macrocysts on US and CT that were not well seen on MR.

Bronchial atresia is common to many non-macrocystic congenital lung lesions, supporting the theory that obstruction may play a primary role in development. Maldevelopment may be present in the absence of macrocysts and may relate to the timing of obstruction. Imaging may not provide definitive diagnosis, but features such as a central mucocele (BA) or very homogeneous pattern (CLE) may help order the differential and guide therapy.

Emerging understanding of natural history and imaging features of congenital lung lesions affects pregnancy management and postnatal care.

Johnson, A, Coleman, B, Kramer, S, Kreiger, P, Wilson, R, Fetal MRI of Non-macrocystic Lung Lesions with Ultrasound, Postnatal CT, and Pathology Correlation.  Radiological Society of North America 2007 Scientific Assembly and Annual Meeting, November 25 - November 30, 2007 ,Chicago IL. http://archive.rsna.org/2007/5008096.html