Differentiating Imaging Features of Post-lobectomy Right Middle Lobe Torsion

Area of Science:

• Radiology
• Thoracic Imaging
• Diagnostic Imaging

Background:

• Lobar torsion is a rare but significant condition.
• Early and accurate diagnosis is crucial for effective management.

Purpose of the Study:

• To identify distinct imaging features differentiating right middle lobe (RML) torsion from suspected cases without torsion.
• To improve the early recognition of RML torsion.

Main Methods:

• Retrospective review of radiology reports and imaging (chest radiographs, CT scans) from April 2014 to April 2021.
• Evaluation of imaging features by four thoracic radiologists.
• Statistical analysis (Fisher exact, Mann-Whitney tests) to compare imaging findings between confirmed torsion and non-torsion groups.

Main Results:

• A reversed halo sign was significantly more frequent in confirmed RML torsion (83.3%) compared to non-torsion cases (0%).
• Confirmed torsion cases showed a larger CT coronal bronchial angle (121.28° vs. 98.26°), increased ground-glass opacity, fissural convexity, and larger lobe volume on CT.
• These imaging features were statistically significant (P<0.05).

Conclusions:

• A reversed halo sign, larger CT coronal bronchial angle, increased ground-glass opacity, fissural convexity, and larger lobe volume are key indicators for RML torsion.
• These findings can assist in the early diagnosis of this rare condition.
• Radiological features play a vital role in identifying lobar torsion.