Systemic Air Embolism Following CT-Guided Percutaneous Lung Procedures: An Imaging Analysis of Divergent Neurological Outcomes.

Systemic air embolism (SAE) is a rare but potentially catastrophic complication of computed tomography (CT)-guided percutaneous lung procedures, with reported incidence ranging from 0.02% to 0.4%. Despite its low frequency, SAE can result in severe neurological impairment or death, yet the factors that determine divergent clinical outcomes remain poorly characterized. We present two cases with contrasting neurological sequelae to elucidate the imaging spectrum and potential prognostic determinants of SAE. In Case 1, a 60-year-old man developed SAE after CT-guided fiducial marker placement for a 7-mm pure ground-glass nodule and achieved full clinical recovery. In Case 2, a 68-year-old man developed SAE following CT-guided percutaneous transthoracic needle biopsy of a 16-mm solid nodule and progressed to persistent semi-comatose status with cortical laminar necrosis. These cases illustrate the heterogeneous neurological outcomes of SAE and underscore the critical role of early post-procedure CT in detecting intravascular gas. Several factors may contribute to divergent outcomes, including procedural technique, nodule characteristics, and the extent and distribution of intracardiac and intracranial air. The absence of hyperbaric oxygen therapy in both patients further highlights the importance of prompt recognition and supportive management. Radiologists and interventionalists must maintain vigilant post-procedural surveillance to facilitate timely diagnosis and optimize patient outcomes.