Cine magnetic resonance imaging for evaluation of focal tracheomalacia: innominate artery compression syndrome

BACKGROUND: The contribution of an 'aberrant innominate artery' to respiratory distress syndromes has been a matter of debate nearly since the introduction of this concept. Recent advances in dynamic imaging are proving to be of value in assessing tracheal function in patients with respiratory distress. We therefore evaluated patients with innominate artery compression syndrome using the cine magnetic resonance imaging (CMRI) modality. OBJECTIVES: To apply the CMRI modality to evaluate patients with respiratory distress who exhibited tracheal compression at the level of the innominate artery. METHODS: A cohort of three patients in respiratory distress underwent bronchoscopy, followed by CMRI using a Siemens 1.5T Vision system. RESULTS: These three patients exhibited tracheal compression at the level of the innominate artery in agreement with their findings during bronchoscopy. All three exhibited dynamic tracheal compression that varied with the respiratory cycle. The degree of tracheal compromise was readily appreciated using the dynamic, real-time CMRI modality. Due to the severity of symptoms, the two children underwent innominate arteriopexy with complete resolution of their symptoms. CONCLUSIONS: CMRI provides extremely rapid acquisition of images, as well as integrated information regarding relationships of mediastinal structures. By providing functional imaging of tracheal patency during the respiratory cycle, CMRI may provide additional insight into innominate artery compression syndrome as more patients are evaluated.