Extralobar Pulmonary Sequestration in a Fetus: Ultrasound, Doppler, CTA, Diagnosis and Treatment
How prenatal Doppler identifies the systemic feeding artery and how postnatal CTA defines the vascular anatomy of fetal extralobar pulmonary sequestration.
Executive Clinical Summary
A fetal thoracic mass discovered during routine prenatal ultrasonography can immediately raise concern for congenital pulmonary airway malformation, diaphragmatic hernia, bronchogenic cyst, or other developmental abnormalities. Yet one imaging feature can fundamentally change the diagnostic pathway: a systemic feeding artery arising from the aorta.
This vascular finding is particularly important in extralobar pulmonary sequestration (ELS), a congenital malformation consisting of nonfunctioning pulmonary tissue that has no normal bronchial communication and is separated from the normally developing lung by its own pleural covering.
The present case illustrates the classic diagnostic sequence.
At 21 weeks of gestation, fetal ultrasound demonstrated a relatively small, homogeneous echogenic mass in the left lower thorax measuring approximately 1.2 × 1.4 × 1.9 cm. The lesion produced little or no significant mediastinal displacement or cardiac compression. Doppler interrogation demonstrated systemic vascular supply and venous drainage.
After birth, chest CT angiography demonstrated a lesion measuring approximately 3.2 × 1.9 × 2.4 cm, surrounded by a thin pleural layer. The feeding artery originated from the aorta at approximately the T10 level, confirming the characteristic systemic vascular anatomy of pulmonary sequestration.
The important clinical lesson is therefore not simply that an echogenic fetal lung mass may represent sequestration. The more useful question is:
Where does the blood supply come from, where does the venous blood drain, and how does the lesion relate anatomically to the normal lung and pleura?
That vascular-anatomic approach helps distinguish ELS from CPAM and other fetal thoracic masses and provides essential information for postnatal management and potential surgery.
Clinical Hook
A 21-week fetus undergoes routine prenatal ultrasonography.
The fetal heart is in its expected position. The lungs are developing normally. There is no major pleural effusion, and there is no obvious hydrops.
Then a small, well-defined echogenic mass is identified in the left lower thorax.
The first impression might be a congenital pulmonary lesion.
But Doppler imaging reveals something more important: a vessel extends from the systemic circulation toward the mass.
The lesion is no longer simply an echogenic lung mass.
Its vascular anatomy becomes the diagnostic clue.
This is the imaging story of extralobar pulmonary sequestration.
Learning Objectives
After reviewing this case, readers should be able to:
Recognize the characteristic prenatal ultrasound appearance of extralobar pulmonary sequestration.
Identify the systemic feeding artery using color or power Doppler.
Understand why arterial origin and venous drainage are critical to diagnosis.
Distinguish extralobar from intralobar pulmonary sequestration.
Differentiate pulmonary sequestration from CPAM, congenital diaphragmatic hernia, bronchogenic cyst, and hybrid lesions.
Understand the role of postnatal chest CTA in defining vascular anatomy and treatment planning.
Interpret the factors that influence observation, surgery, or vascular intervention.
Understand realistic applications of AI in fetal and pediatric thoracic imaging.
Anatomy and Pathophysiology
Pulmonary sequestration is a congenital abnormality in which a portion of lung tissue develops without normal communication with the tracheobronchial tree and receives arterial blood from the systemic circulation rather than the normal pulmonary arterial circulation.
The precise embryologic mechanism remains incompletely established.
In extralobar pulmonary sequestration, the abnormal pulmonary tissue is separated from the normal lung by its own pleural investment. The lesion therefore behaves anatomically as an accessory or isolated pulmonary mass rather than as part of the normal pulmonary parenchyma.
Three anatomical characteristics are particularly important:
1. Abnormal pulmonary tissue
The sequestered tissue does not participate normally in ventilation.
2. Systemic arterial supply
Instead of receiving its principal arterial supply from the pulmonary artery, the lesion is supplied by an anomalous systemic artery.
The descending thoracic or abdominal aorta is a common source.
3. Separate pleural covering
The extralobar lesion has its own pleural envelope.
This feature is central when differentiating ELS from intralobar sequestration.
The prenatal imaging literature describes ELS as a well-defined homogeneous echogenic mass, frequently located in the lower thorax, with demonstration of a systemic artery from the aorta being a particularly useful diagnostic finding.
Prenatal Ultrasound Findings
Prenatal ultrasound is usually the first imaging examination to identify ELS.
The lesion commonly appears as a:
Well-defined mass
Homogeneous echogenic lesion
Solid-appearing thoracic mass
Lower thoracic lesion
Often left-sided lesion
Lesion adjacent to the diaphragm
However, echogenicity alone is not diagnostic.
The same general appearance can be encountered with other congenital thoracic lesions.
Therefore, the examination should progress from morphology to vascular anatomy.
Case Imaging at 21 Weeks
In this case, ultrasound at 21 weeks demonstrated:
Location: left lower thorax
Morphology: small, homogeneous echogenic mass
Approximate dimensions: 1.2 × 1.4 × 1.9 cm
Systemic feeding vessel: present
Venous drainage: identified
Mediastinal shift: minimal or absent
Cardiac compression: minimal or absent
The combination of a solid echogenic mass and systemic arterial supply strongly supports pulmonary sequestration.
Transverse Fetal Chest Ultrasound
Figure 1. Normal fetal thoracic anatomy on transverse ultrasound.
Radiology interpretation: The transverse plane demonstrates the expected relationship between the fetal lungs, heart, thoracic cavity, and mediastinum. This baseline anatomical orientation provides a reference for identifying an abnormal echogenic mass.
Clinical significance: Accurate identification of the fetal thoracic compartments is essential before characterizing a suspected pulmonary lesion.
ALT text: Transverse fetal ultrasound demonstrating normal thoracic anatomy.
Sagittal Fetal Chest Ultrasound
Figure 2. Sagittal ultrasound demonstrating the fetal left lower thorax and diaphragm.
Radiology interpretation: The sagittal plane helps establish the cranio-caudal location of the lesion and its relationship to the diaphragm.
Clinical significance: Determining whether a mass is intrathoracic, subdiaphragmatic, or crossing the diaphragmatic boundary is important when considering pulmonary sequestration and congenital diaphragmatic hernia.
ALT text: Sagittal fetal ultrasound showing the left lower thorax and diaphragm.
Doppler Identification of the Systemic Feeding Artery
This is the pivotal imaging step.
When a fetal thoracic mass is identified, color or power Doppler should be used deliberately to search for an anomalous systemic arterial supply.
The sonographer should not simply ask:
“Is there blood flow?”
The more useful question is:
“Where does the feeding artery originate?”
A vessel entering the lesion from the aorta is substantially more informative than nonspecific internal vascularity.
Prenatal studies have demonstrated the value of Doppler for identifying systemic feeding arteries in bronchopulmonary sequestration and hybrid lesions.
Transverse Doppler Ultrasound
Figure 3. Color Doppler demonstration of systemic vascular supply and venous drainage.
Radiology interpretation: Doppler demonstrates vascular communication between the fetal systemic circulation and the echogenic thoracic mass.
Clinical significance: Demonstration of a systemic feeding artery is the key vascular clue supporting pulmonary sequestration.
ALT text: Color Doppler ultrasound showing systemic vascular supply to an echogenic fetal thoracic mass.
Coronal Doppler Ultrasound
Figure 4. Coronal Doppler imaging demonstrating the direction of the systemic feeding vessel.
Radiology interpretation: The vascular course should be followed from the lesion toward its proximal arterial origin rather than stopping at the point where the vessel enters the mass.
Clinical significance: Establishing the direction and origin of the vessel improves diagnostic confidence and provides preliminary information for postnatal vascular mapping.
ALT text: Coronal fetal Doppler demonstrating a systemic feeding artery entering pulmonary sequestration.
Postnatal Chest CTA
After birth, contrast-enhanced chest CT angiography can provide a more complete anatomical map.
In this case, CTA demonstrated:
Lesion size: approximately 3.2 × 1.9 × 2.4 cm
Location: left lower thorax
Thin pleural layer surrounding the lesion
Systemic arterial supply
Feeding artery arising from the aorta at approximately T10
Remaining lung described as normal
The CTA therefore transformed the prenatal vascular suspicion into a detailed anatomical diagnosis.
Why CTA Matters
Postnatal CTA should not be regarded simply as a test to “confirm a mass.”
Its most important purpose is vascular mapping.
The radiologist should identify:
Number of feeding arteries
Origin of each feeding artery
Diameter of the feeding artery
Course of the vessel
Lesion location
Pleural relationship
Venous drainage
Relationship to the diaphragm
Relationship to normal lung
Associated congenital anomalies or hybrid components
Multiplanar and three-dimensional reconstructions can be particularly useful for preoperative planning. Current imaging literature similarly emphasizes contrast-enhanced CT or MR for postnatal characterization of pulmonary sequestration and its anomalous vascular anatomy.
Axial Contrast-Enhanced Chest CTA
Figure 5. Axial chest CTA demonstrating the left lower thoracic lesion and feeding artery.
Radiology interpretation: The lesion is separated from the normally aerated lung and demonstrates systemic arterial supply.
Clinical significance: Axial CTA establishes the lesion's relationship to adjacent lung and identifies the vascular pedicle.
ALT text: Axial contrast-enhanced chest CT showing extralobar pulmonary sequestration and systemic feeding artery.
Arterial-Phase CTA
Figure 6. Arterial-phase CTA demonstrating systemic arterial supply.
Radiology interpretation: The feeding vessel enhances synchronously with the systemic arterial circulation and is distinguishable from the pulmonary arterial branches.
Clinical significance: Identification of systemic rather than pulmonary arterial supply is fundamental to the diagnosis.
ALT text: Arterial-phase CT angiography demonstrating systemic arterial supply to pulmonary sequestration.
Sagittal CTA
Figure 7. Sagittal CTA demonstrating the course of the feeding artery.
Radiology interpretation: The feeding artery can be followed along its course toward the sequestered tissue, with its origin identified at approximately the T10 aortic level in this case.
Clinical significance: Knowledge of the exact vascular origin is important for operative or endovascular planning.
ALT text: Sagittal CTA showing the course of an aortic feeding artery to extralobar pulmonary sequestration.
Axial CTA
Figure 9. Axial CTA demonstrating lesion and vascular anatomy.
Radiology interpretation: The Axial plane provides an overview of the relationship among the sequestration, normal lung, diaphragm, and systemic feeding artery.
Clinical significance: Multiplanar vascular mapping can reduce the risk of overlooking additional feeding vessels.
ALT text: Coronal chest CTA showing extralobar pulmonary sequestration and systemic vascular anatomy.
Extralobar vs Intralobar Pulmonary Sequestration
| Feature | Extralobar Sequestration | Intralobar Sequestration |
|---|---|---|
| Pleural covering | Separate pleural envelope | Shares pleura with normal lung |
| Bronchial communication | Absent | Usually absent |
| Arterial supply | Systemic artery | Systemic artery |
| Venous drainage | More often systemic venous drainage | More often pulmonary venous drainage |
| Typical location | Lower thorax, often left | Lower lobes, often left |
| Prenatal detection | Relatively common | Less commonly detected prenatally |
| Typical presentation | Often asymptomatic or neonatal | Recurrent infection more characteristic |
| Associated anomalies | May occur | Less characteristic |
| Surgical anatomy | Separate pleural mass | Embedded within normal lung |
The pleural relationship is one of the most useful anatomical distinctions.
If the lesion has its own pleural envelope, ELS becomes more likely.
In the present case, the thin pleural layer demonstrated on CTA supports the diagnosis of extralobar sequestration.
Differential Diagnosis
1. Congenital Pulmonary Airway Malformation
CPAM is an important differential diagnosis for an echogenic fetal thoracic lesion.
The appearance may be solid, microcystic, or multicystic depending on the lesion.
The critical distinction is vascular.
A systemic feeding artery favors pulmonary sequestration.
A lesion with both cystic pulmonary malformation and systemic arterial supply raises consideration of a hybrid lesion.
Prenatal color or power Doppler is therefore useful when evaluating suspected CPAM and related congenital lung lesions.
2. Congenital Diaphragmatic Hernia
CDH should be considered when a lower thoracic mass is associated with abnormal diaphragmatic anatomy.
Important questions include:
Is the diaphragm intact?
Is the stomach located normally?
Are bowel loops present within the thorax?
Is the liver herniated?
Is the normal lung compressed?
Is there significant mediastinal displacement?
Unlike ELS, CDH represents herniation of abdominal contents through a diaphragmatic defect.
3. Bronchogenic Cyst
A bronchogenic cyst usually demonstrates a cystic appearance rather than a homogeneous solid echogenic mass.
A typical systemic feeding artery is not the defining feature.
Therefore, identification of an aortic feeding artery should shift the diagnostic focus toward sequestration.
4. Neurogenic or Suprarenal Mass
A lower thoracic or paravertebral mass may occasionally overlap anatomically with a suprarenal or retroperitoneal lesion.
The relationship to the diaphragm, adrenal region, spine, and aorta should be carefully evaluated.
If the mass is supplied by a characteristic systemic arterial branch, pulmonary sequestration becomes more plausible, but the complete anatomical relationship remains important.
5. Hybrid Lesion
A hybrid lesion combines features of pulmonary sequestration and CPAM.
This possibility is especially important when:
The lesion has cystic components.
A systemic feeding artery is present.
The imaging appearance is not purely solid.
Postnatal imaging demonstrates both abnormal vascular supply and congenital airway malformation.
Multimodal Imaging Comparison
| Modality | Main Strength | Important Limitation | Best Clinical Question |
|---|---|---|---|
| Prenatal ultrasound | Real-time fetal anatomy | Operator and fetal-position dependence | Is there a thoracic mass? |
| Color Doppler | Systemic feeding artery | Small vessels may be difficult to trace | Where does the blood supply originate? |
| Power Doppler | Sensitive flow detection | Less directional information | Is abnormal vascularity present? |
| Fetal MRI | Tissue characterization and thoracic anatomy | Less direct vascular detail than Doppler/CTA in some cases | What is the extent of the lesion? |
| Chest CTA | Detailed arterial anatomy | Ionizing radiation | What is the vascular anatomy for diagnosis/planning? |
| 3D CTA reconstruction | Spatial vascular mapping | Requires appropriate acquisition/reconstruction | How should the lesion be approached surgically? |
Imaging Diagnostic Algorithm
Treatment and Timing
The discovery of ELS does not automatically mean that immediate fetal or neonatal surgery is required.
Management should be individualized.
A small lesion with no significant mediastinal shift, cardiac compression, hydrops, or respiratory compromise may be followed with serial imaging.
Conversely, intervention becomes more relevant when the lesion produces significant physiological consequences.
Potential concerns include:
Significant respiratory compromise
Large lesion
Progressive growth
Pleural effusion
Hydrops
Cardiovascular burden
Significant systemic arterial shunting
Recurrent infection
Vascular complications
Persistent uncertainty regarding the diagnosis
Some ELS lesions can decrease substantially in apparent size during pregnancy or after birth. However, apparent prenatal regression does not necessarily mean complete anatomical disappearance; postnatal imaging may still demonstrate residual abnormal tissue or vascular anatomy.
This distinction is clinically important.
“No longer visible on prenatal ultrasound” does not necessarily mean “no lesion exists after birth.”
Surgical and Embolization Considerations
Surgical resection remains an established definitive treatment for symptomatic or clinically significant pulmonary sequestration.
The separate pleural envelope of ELS may make anatomical resection relatively straightforward compared with lesions embedded within normal lung.
Before surgery, the radiologist should provide a vascular roadmap.
Preoperative CTA checklist
Arterial anatomy
Feeding artery origin
Number of feeding arteries
Vessel diameter
Course
Relationship to the diaphragm
Lesion anatomy
Exact location
Size
Pleural relationship
Relationship to normal lung
Venous anatomy
Systemic venous drainage
Pulmonary venous drainage
Unusual venous channels
Associated disease
CPAM
Hybrid lesion
Diaphragmatic abnormality
Other congenital anomalies
A crucial practical point is that lesion size does not necessarily predict feeding artery size or systemic flow.
Therefore, vascular assessment should not be omitted simply because the lesion appears small.
Embolization
Endovascular embolization may be considered in selected patients, particularly when the systemic arterial supply has clinically meaningful physiological effects or when an endovascular approach is otherwise appropriate.
The choice between observation, embolization, and surgery depends on the patient's anatomy, symptoms, vascular physiology, associated anomalies, and institutional expertise.
Prognosis
Isolated ELS generally has a favorable prognosis, particularly when:
The lesion is small.
Normal lung development is preserved.
There is little or no mediastinal displacement.
There is no major cardiac compression.
There is no hydrops.
There is no severe pleural effusion.
There are no major associated anomalies.
The present case contains several favorable imaging characteristics.
At 21 weeks, the lesion was relatively small, with minimal mass effect and no substantial cardiac compression.
This is different from cases in which a large lesion produces hydrothorax, hydrops, or major cardiovascular compromise.
Therefore, the prenatal imaging report should describe not only what the lesion is, but also what physiological effect it is producing.
AI in Fetal and Pediatric Thoracic Imaging
Artificial intelligence may eventually assist in detecting congenital thoracic abnormalities, but its most useful role is likely to be augmentation rather than autonomous diagnosis.
Potential AI applications
1. Automated fetal thoracic segmentation
AI could identify:
Fetal lungs
Heart
Diaphragm
Mediastinum
Thoracic lesion
2. Lesion detection
Computer vision systems could flag unexpected echogenic thoracic abnormalities during screening.
3. Vascular detection
AI-assisted Doppler analysis could potentially trace an abnormal vessel from the aorta toward the lesion.
This is particularly relevant because the systemic feeding artery is one of the most diagnostically informative features of sequestration.
4. Quantitative volumetry
Automated lesion volume calculation could provide objective measurements during serial follow-up.
5. Longitudinal monitoring
AI could compare sequential examinations and identify:
Growth
Regression
Increasing mediastinal displacement
New pleural effusion
Changes in vascular morphology
6. Postnatal CTA segmentation
AI could assist in automatically extracting:
aorta → feeding artery → sequestration → venous drainage
from three-dimensional CTA datasets.
AI Workflow for Pulmonary Sequestration
The critical point is that the AI system should not simply output:
“Pulmonary sequestration detected.”
A clinically useful system should ideally show why the lesion was flagged.
For example:
Lesion location
Feeding artery
Arterial origin
Lesion volume
Mediastinal displacement
Pleural effusion
Confidence level
Human review remains essential because fetal ultrasound is highly dependent on fetal position, acoustic windows, operator technique, and image quality.
PACS/RIS/EMR and Enterprise Imaging Workflow
For pediatric congenital abnormalities, interoperability is particularly important because the clinical pathway may involve:
Maternal-fetal medicine
Radiology
Pediatric radiology
Neonatology
Pediatric surgery
Pediatric cardiology
Anesthesiology
An AI result that cannot be integrated into the existing clinical workflow is unlikely to provide meaningful clinical value regardless of its technical performance.
Expert Insights
Expert Insight 1
The most important feature of a fetal echogenic thoracic mass may not be its echogenicity but its arterial supply.
Expert Insight 2
A systemic artery from the aorta should trigger a focused evaluation for pulmonary sequestration.
Expert Insight 3
The origin of the feeding artery should be documented, not merely the presence of flow.
Expert Insight 4
Venous drainage can help distinguish extralobar from intralobar sequestration.
Expert Insight 5
Pleural anatomy provides an important anatomical discriminator between ELS and ILS.
Expert Insight 6
A small lesion can still have clinically relevant vascular anatomy.
Expert Insight 7
Prenatal regression does not necessarily equal complete anatomical resolution.
Expert Insight 8
CTA should be interpreted as a vascular roadmap rather than simply a mass-detection examination.
Expert Insight 9
The presence of a systemic feeding artery does not exclude a hybrid lesion.
Expert Insight 10
Management should be based on lesion anatomy and physiological effect rather than lesion detection alone.
Clinical Pearls
Think vascular when you see an echogenic fetal lung mass.
Search for a systemic feeding artery.
Trace the vessel back to its origin.
Do not stop after identifying internal vascularity.
Assess venous drainage.
Evaluate the pleural relationship.
Look for mediastinal shift and cardiac compression.
Search for pleural effusion and hydrops.
Evaluate the diaphragm carefully.
Consider CPAM and hybrid lesions.
Postnatal CTA should map the feeding artery precisely.
Look for additional feeding arteries.
Do not assume lesion size predicts vascular flow.
Prenatal disappearance does not necessarily mean anatomical cure.
The radiologist's vascular map can directly influence surgical planning.
Common Diagnostic Pitfalls
Pitfall 1: Diagnosing by echogenicity alone
An echogenic mass is a description, not a diagnosis.
Pitfall 2: Failing to use Doppler
A routine grayscale examination may miss the most important diagnostic feature.
Pitfall 3: Identifying flow without determining origin
Internal vascularity is less informative than establishing systemic arterial origin.
Pitfall 4: Ignoring venous drainage
Venous anatomy contributes to lesion classification.
Pitfall 5: Confusing ELS with CPAM
A solid lesion can be mistaken for another congenital pulmonary abnormality unless vascular anatomy is evaluated.
Pitfall 6: Assuming all lesions require immediate surgery
Management should reflect symptoms, physiology, vascular anatomy, and associated abnormalities.
Pitfall 7: Assuming spontaneous regression means complete resolution
Residual lesions may remain demonstrable after birth.
Pitfall 8: Failing to inspect the diaphragm
Lower thoracic lesions can overlap anatomically with diaphragmatic hernia.
FAQ
What is extralobar pulmonary sequestration?
Extralobar pulmonary sequestration is a congenital mass of nonfunctioning pulmonary tissue that lacks normal bronchial communication, receives systemic arterial blood, and is separated from the normal lung by its own pleural covering.
What is the most important prenatal imaging finding?
The key imaging clue is an anomalous systemic feeding artery, particularly one arising from the aorta.
Where is ELS usually located?
It most commonly occurs in the lower thorax and is frequently left-sided.
Can ELS be detected before birth?
Yes. Prenatal ultrasound can identify ELS, sometimes during the second trimester.
Is color Doppler important?
Yes. Doppler can demonstrate the systemic feeding artery and can help characterize vascular anatomy.
What does CTA add after birth?
CTA can define the origin, number, course, and size of feeding arteries and demonstrate the lesion's relationship to the normal lung and surrounding structures.
How is ELS different from ILS?
ELS has its own pleural covering, whereas ILS is contained within the pleura of the normal lung.
Does every ELS require immediate surgery?
No. Management depends on symptoms, lesion behavior, vascular anatomy, associated anomalies, and physiological effects.
Can an ELS lesion regress?
Yes, apparent prenatal regression can occur. However, postnatal imaging may still demonstrate residual abnormal tissue or vascular anatomy.
Can ELS be associated with CPAM?
Yes. A lesion containing both sequestration and CPAM components is generally described as a hybrid lesion.
Quiz
Question 1
A fetus at 21 weeks has a 1.2 × 1.4 × 1.9 cm homogeneous echogenic mass in the left lower thorax. Doppler demonstrates a systemic feeding artery, with minimal mediastinal displacement.
What is the most likely diagnosis?
A. Bronchogenic cyst
B. Congenital diaphragmatic hernia
C. Extralobar pulmonary sequestration
D. Isolated pleural effusion
E. Neuroblastoma
Answer: C. Extralobar pulmonary sequestration
Question 2
Which anatomical feature is most useful in distinguishing extralobar from intralobar pulmonary sequestration?
A. Lesion echogenicity
B. Lesion size
C. Pleural relationship
D. Presence of mediastinal shift
E. Fetal heart rate
Answer: C. Pleural relationship
Question 3
A feeding artery to a left lower thoracic mass originates from the aorta around the T10 level. What does this finding indicate?
A. Pulmonary arterial hypertension
B. Systemic arterial supply to a pulmonary sequestration
C. Isolated bronchogenic cyst
D. Simple CPAM without vascular anomaly
E. Pleural effusion
Answer: B. Systemic arterial supply to a pulmonary sequestration
Question 4
Which finding should raise suspicion for a hybrid lesion?
A. Systemic artery with a completely solid lesion
B. Normal lung anatomy
C. Cystic pulmonary components combined with systemic arterial supply
D. Absence of mediastinal shift
E. Normal fetal heart
Answer: C. Cystic pulmonary components combined with systemic arterial supply
Question 5
What is the principal purpose of postnatal CTA in a suspected ELS?
A. Measuring fetal growth
B. Determining maternal blood pressure
C. Mapping systemic vascular anatomy
D. Diagnosing infection alone
E. Measuring fetal cardiac output
Answer: C. Mapping systemic vascular anatomy
Key Takeaways
Extralobar pulmonary sequestration is fundamentally a vascular-anatomic diagnosis.
When a fetal echogenic thoracic mass is identified:
Determine its location.
Assess its morphology.
Use color or power Doppler.
Search for a systemic feeding artery.
Trace the artery to its origin.
Assess venous drainage.
Determine pleural anatomy.
Look for effusion, mediastinal shift, cardiac compression, and hydrops.
Evaluate for associated congenital anomalies.
Use postnatal CTA to map the vascular anatomy.
Integrate imaging findings with clinical physiology.
Avoid assuming that detection automatically requires immediate intervention.
The most important imaging lesson can be summarized in one sentence:
When a fetal thoracic mass is echogenic, look for the vessel before deciding what the mass is.
Internal link
References
Oliver, E. R., DeBari, S. E., Giannone, M. M., et al., “Going with the flow: An aid in detecting and differentiating bronchopulmonary sequestrations and hybrid lesions,” Journal of Ultrasound in Medicine, vol. 37, no. 2, pp. 371–383, 2018. doi: 10.1002/jum.14346.
Ruano, R., Aubry, M.-C., and others, “Prenatal diagnosis of pulmonary sequestration using three-dimensional power Doppler ultrasound,” Ultrasound in Obstetrics & Gynecology, 2005.
Witlox, R. S. G. M., Lopriore, E., Oepkes, D., et al., “Prenatal sonography and MR imaging of pulmonary sequestration,” AJR American Journal of Roentgenology, vol. 180, no. 2, 2003.
Laberge, J.-M., Bratu, I., and Flageole, H., “The management of congenital lung lesions,” Clinical Perinatology, vol. 30, no. 3, pp. 675–688, 2003.
Wei, Y. and Li, F., “Pulmonary sequestration: A retrospective analysis of 2625 cases in China,” European Journal of Cardio-Thoracic Surgery, vol. 40, no. 1, pp. e39–e42, 2011.
Savic, B., Birtel, F. J., Tholen, W., Funke, H. D., and Knoche, R., “Lung sequestration: Report of seven cases and review of 540 published cases,” Thorax, vol. 29, pp. 122–132, 1974.
Ikezoe, J., Murayama, S., Godwin, J. D., et al., “Bronchopulmonary sequestration: CT assessment,” Radiology, 1990.
Corbett, H. J. and Humphrey, G. M., “Pulmonary sequestration,” Paediatric Respiratory Reviews, vol. 8, pp. 16–24, 2007.
Riedlinger, W. F. J., Vargas, S. O., Jennings, R. W., et al., “Bronchopulmonary sequestration: An update on pathogenesis and diagnosis,” Pediatric and Developmental Pathology, 2006.
MacSweeney, F., Papagiannopoulos, K., Goldstraw, P., et al., “Extralobar sequestration of the lung: Clinical and imaging findings,” European Journal of Cardio-Thoracic Surgery, 2003.
Mon, R. A., Johnson, K. N., Ladino-Torres, M., et al., “Diagnostic accuracy of imaging studies in congenital lung malformations,” Archives of Disease in Childhood — Fetal and Neonatal Edition, vol. 104, no. 4, pp. F372–F377, 2019.
Kellenberger, C. J., “Congenital malformations of the lung and airways: Radiologic-pathologic correlation,” Pediatric Radiology.
“Vascular Anatomy in Congenital Lung Lesions—Description and Classification,” Frontiers in Pediatrics, 2022.
“Pediatric congenital pulmonary malformations: Key findings at imaging,” Clinical and Translational Imaging, 2024.
Bisht, S., Pal, A., and Sharma, G., “Congenital Pulmonary Airway Malformation,” StatPearls, updated June 17, 2026.
Medical Disclaimer
This article is intended for medical education and professional information. It does not replace individualized evaluation by a qualified physician, radiologist, maternal-fetal medicine specialist, neonatologist, pediatric surgeon, or other healthcare professional.
Management of fetal and neonatal pulmonary sequestration should be determined according to the individual patient's imaging findings, clinical condition, vascular anatomy, associated abnormalities, institutional expertise, and current clinical evidence.
Featured Snippet Answer
What is extralobar pulmonary sequestration?
Extralobar pulmonary sequestration is a congenital mass of nonfunctioning pulmonary tissue without normal bronchial communication. It is separated from the normal lung by its own pleural covering and receives systemic arterial blood, often from the thoracic or abdominal aorta. Prenatal Doppler detection of this systemic feeding artery is a key diagnostic feature.
Frequently Asked Questions
What is
extralobar pulmonary sequestration?
Extralobar pulmonary sequestration is a
congenital mass of nonfunctioning pulmonary tissue without normal bronchial
communication. It is separated from the normal lung by its own pleural covering
and receives systemic arterial blood, often from the thoracic or abdominal
aorta.
What does
pulmonary sequestration look like on fetal ultrasound?
It typically appears as a well-defined,
homogeneous echogenic mass, often in the lower thorax. Demonstration of a
systemic feeding artery on Doppler is an important diagnostic clue.
Why is the
systemic feeding artery important?
A systemic feeding artery, particularly
one arising from the aorta, is a characteristic vascular feature of pulmonary
sequestration and helps distinguish it from other fetal thoracic masses.
Can
pulmonary sequestration be detected prenatally?
Yes. Extralobar pulmonary sequestration
can be detected during prenatal ultrasound, particularly when color Doppler
demonstrates the characteristic systemic arterial supply.
What is the
difference between ELS and ILS?
The key anatomical distinction is the pleural
relationship. Extralobar sequestration has its own pleural covering, whereas
intralobar sequestration shares the pleura of the normal lung.
What does
chest CTA show in pulmonary sequestration?
Chest CTA can define the feeding
artery, its aortic origin and course, venous drainage, lesion location, pleural
relationship, and associated congenital abnormalities.
Can
extralobar pulmonary sequestration disappear?
Some lesions may decrease in apparent
size or become difficult to visualize during prenatal or postnatal follow-up.
However, apparent regression does not necessarily prove complete anatomical
resolution.
Does every
extralobar pulmonary sequestration require surgery?
No. Management depends on symptoms,
lesion behavior, vascular anatomy, associated abnormalities, and physiological
effects. Clinicians may consider observation, surgery, or selected vascular intervention based on the individual clinical situation.
What is a
hybrid CPAM lesion?
A hybrid lesion contains features of
both congenital pulmonary airway malformation and pulmonary sequestration,
including abnormal pulmonary architecture together with systemic arterial
supply.
What role
can AI play in fetal thoracic imaging?
AI may assist with lesion detection, fetal thoracic
segmentation, vascular identification, quantitative measurements, longitudinal
follow-up, and postnatal CTA analysis. Clinical interpretation and
decision-making still require appropriate professional oversight.
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