Fetal MR Imaging of Congenital Cystic Lung Diseases

Abstract

Fetal magnetic resonance imaging (MRI) is difficult owing to fetal movement, fetal size, and maternal artifacts. Also, the diagnosis of congenital anomalies is more difficult by MRI than by other types of imaging. Careful monitoring of the development of fetal lung parenchyma, especially of the incremental signal intensities that correspond to gestational age (weeks), is important. For the evaluation and diagnosis of congenital cystic lung disease, attention should be given to the size, number, and signal intensity of cystic lesions. Identification of atypical solid-type congenital pulmonary airway malformations is useful when a low-signal-intensity mass-like lesion is discovered in a fetal lung. A single-shot turbo spin-echo sequence is necessary for the detection of the aberrant artery of bronchopulmonary sequestration. On the basis of the typical symptoms of congenital high airway obstruction syndrome (CHAOS), including hyperinflated bilateral lungs and a small heart, a correct diagnosis of typical CHAOS is not difficult. However, some cases of CHAOS have associated tracheoesophageal fistula with mild lung inflation. Thus, we should evaluate mild lung inflation carefully. In this review article, we introduce typical and atypical fetal lung anomalies with diagnostic characteristics determined by fetal MRI.