Imaging Features to Distinguish Intralobar Versus Extralobar Bronchopulmonary Sequestration

Area of Science:

• Radiology
• Thoracic Surgery
• Pathology

Background:

• Bronchopulmonary sequestration (BPS) is a congenital lung malformation.
• Differentiating intralobar sequestration (ILS) from extralobar sequestration (ELS) is crucial for management.
• Hybrid lesions, BPS with congenital pulmonary airway malformation, present diagnostic challenges.

Purpose of the Study:

• To evaluate CT characteristics of BPS.
• To identify imaging features distinguishing ILS from ELS.
• To correlate CT findings with hybrid lesions and sequestration subtypes.

Main Methods:

• Retrospective multicenter study of 52 surgical pathology specimens of BPS.
• Analysis of preoperative CT imaging features including vascular anatomy and parenchymal changes.
• Correlation of imaging findings with pathologic diagnoses, including hybrid lesions.

Main Results:

• Venous drainage differed significantly: 11% ILS vs. 57% ELS drained to the systemic venous system (P=0.013).
• ILS were mostly inseparable (98%) from lung, while ELS were often separate (57%) (P<0.001).
• Cystic changes on CT were more frequent in hybrid lesions (7/12) and overall (17/40) than pathologically confirmed.

Conclusions:

• Distinguishing ILS from ELS based on venous drainage and separability is imperfect.
• CT findings of cystic abnormalities may exceed pathologic confirmation of hybrid lesions.
• Hybrid lesions might be underdiagnosed in pathologic analysis.