ULTRASOUND OF

BRONCHOPULMONARY SEQUESTRATION

• Well defined, homogeneous, highly echogenic mass.
• Most common in the lower lobes (especially the posterior basal segments) or upper abdomen. Both intralobar and extra-lobar sequestration may appear simultaneously and bilaterally.

INTRALOBAR

• Equal frequency on the left and right sides.
• Spherical in shape.
• Color Doppler.
• Large single artery coursing through the pulmonary ligament from:
• distal thoracic aorta (73%).
• proximal abdominal aorta (22%).
• celiac or splenic artery.
• Venous drainage via the pulmonary veins to:
• left atrium (left to left shunt) (95%).
• right atrium (5%).

EXTRALOBAR

• 80%-90% occur in the left hemithorax - Intrathoracic extralobar (1,2).
• 5% occur below the diaphragm - Extrathoracic extralobar.
• Conical or triangular shaped mass (this shape results from its complete pleural investment and narrow vascular pedicle).

Intrathoracic Extralobar Bronchopulmonary Sequestration
Intrathoracic extralobar pulmonary sequestration Triangular shaped echogenic mass. Mass in left lower lobe. No ascites, hydrops or pleural effusions.
Triangular echogenic mass in left hemithorax with a well defined vessel arising from the thoracic aorta
Extrathoracic Extralobar Bronchopulmonary Sequestration

• Pleural effusions (3,4) and mediastinal shift may occur (53% in Langer and co-workers series) (4).
• Polyhydramnios (59%) (4).
• Fetal hydrops (edema, ascites and hydrothorax due to obstructed lymphatics and veins in torsed sequestration).
• Color Doppler.
• Demonstrates the vascular nature of the lesion.
• Arterial supply (5-7).
• aorta as a single branch or multiple small branches (80%).
• splenic, gastric, subclavian and intercostal branches (15%).
• pulmonary artery (5%).
• Venous drainage mapping may allow differentiation of intralobar from extralobar sequestration (5).
• systemic veins (80%) to right side of heart (IVC, azygos, hemiazygos, portal vein).
• pulmonary vein (20%).
• May rarely occur infra-diaphragmatically or intra-abdominally (8,9).
• Well-circumscribed echogenic intra-abdominal mass.

REFERENCES

1. Thomas CS, Leopold GR, Hilton S et.al. Fetal hydrops associated with extralobar pulmonary sequestration. J Ultrasound Med 1986;5:668-671.
2. West MS, Donaldson JS, Shkolnik A. Pulmonary sequestration: Diagnosis by ultrasound. J Ultrasound Med 1989;8:125-129.
3. Favre K, Bettahar D, Christmann D et.al. Antenatal diagnosis and treatment of fetal hydrops secondary to pulmonary sequestration. Ultrasound Obstet Gynecol 1994;4:335-338.
4. Langer B, Donato L, Riethmuller C et.al. Spontaneous regression of fetal pulmonary sequestration. Ultrasound Obstet Gynecol 1995;6:33-39.
5. Sauerbrei E. Lung sequestration: Duplex doppler diagnosis at 19 weeks gestation. J Ultrasound Med 1991;10:101-105.
6. MacGillivray TE, Harrison MR, Goldstein RB et.al. Disappearing fetal lung lesions. J Pediatr Surg 1993;28:1321-1325.
7. Sands RH, Lilford RJ. Hyperechogenic areas detected in fetal chest at routine ultrasound examination. Three cases. Prenat Diagn 1992;12:79-82.
8. Weinbaum PJ, Bors-Koefoed R, Green KW et.al. Antenatal sonographic findings in a case of intra-abdominal pulmonary sequestration.
9. Davies RF, Ford WDA, Lequesne GW et.al. Ultrasonic detection of subdiaphragmatic pulmonary sequestration in utero and post natal diagnosis by fine needle aspiration biopsy. J Ultrasound Med 1989;8:47-49.