Comparison between US and MRI in the prenatal assessment of lung malformations.

BACKGROUND: The contribution of MRI in the prenatal evaluation of congenital lung abnormalities (CLA) has not been extensively investigated.

OBJECTIVE: (1) To compare diagnostic accuracy and assessment of prognostic factors between US and MRI in CLA and (2) to assess the diagnosis agreement between prenatal imaging and postnatal diagnosis.

MATERIALS AND METHODS: We included 23 consecutive fetuses who underwent concomitant US and MRI during gestation as well as postnatal CT and surgery (n = 22).

RESULTS: US-MRI sets were performed at median gestational age of 26 (n = 16) and 34 (n = 22) weeks. Postnatal diagnoses were 11 congenital pulmonary airway malformations (CPAM), 4 bronchopulmonary sequestrations (BPS), 6 hybrid lesions and 2 cysts. US and MRI agreement was significantly better during the second trimester than during the third one (P = 0.02). Disagreements were related to missed cysts (n = 5), mediastinal shift (n = 6) and vessels (n = 5). US and MRI diagnosis agreement was present in 20 cases, including 5 cases of misdiagnosis. US and MRI were concordant with postnatal diagnosis in 17 and 16 cases, respectively.

CONCLUSION: In our series, no clear superiority of MRI over US in the prenatal evaluation of CLA was demonstrated, but US better demonstrated systemic feeding vessels and MRI cysts and normal lung adjacent to the lesion.