Presentation
Abnormal echogenicity in the right lower lung zone on second trimester ultrasound. Followed up with MRI
Patient Data
There is a region of abnormal T2 signal intensity in the right lower lung zone, with an abnormal feeding vessel which arises directly off the aorta. Findings are compatible with a pulmonary sequestration.
There is a prominent cisterna magna or retrocerebellar arachnoid cyst. The brain is grossly normal.
The image has been rotated to put the fetus in typical position. The mother's bladder is above the fetal head in these images.
The open red arrow points to the prominent non-pulmonary vascular supply to the region of abnormal signal in the right lower lobe, compatible with a pulmonary sequestration.
Case Discussion
This case demonstrates the classic findings of pulmonary sequestration on MRI.
The sequestered segment does not communicate with the rest of the bronchopulmonary system, and thus, even though the lung is not aerated, it has a different signal intensity than the rest of the lung.
A systemic arterial feeding vessel, arising directly off the aorta, is also visible.
This sequestration had been seen earlier in the second trimester and was being monitored. ~50% resolve in utero.
The differential includes: