Usefulness of magnetic resonance imaging for evaluation of cardiovascular invasion: Evaluation of sliding motion between thoracic mass and adjacent structures on cine MR images

Purpose: To determine the feasibility and usefulness of magnetic resonance imaging (MRI) for evaluating cardiovascular invasion of a thoracic mass by demonstrating the sliding motion between the mass and adjacent structures, Materials and Methods: Twenty-six patients (17 males and nine females, mean age = 49 years) were included in this study. They all had thoracic masses with equivocal cardiovascular invasion on chest CT scan and/or MRI that were surgically confirmed. The pathologic diagnoses were teratoma/thymic tumor (N = 12), lung cancer (N = 9), and other thoracic tumor (N = 5). Conventional T1/T2, contrast-enhanced, and breathheld ECG-gated cine MRI using a steady-state free precession (SSFP) technique was performed. The results were compared to the surgical reports. Results: The cine MR images showed the presence of sliding motion in 39 structures in 20 patients, which were surgically confirmed as not being invaded, and 15 structures in six patients with the absence of sliding motion noted as tumor invasion. Therefore, the accuracy of the cine MR images was 94.4% (51/54) for evaluating cardiovascular invasion of a thoracic mass. Conclusion: MRI can provide additional information and improve the accuracy of preoperative staging for predicting cardiovascular invasion of a thoracic mass by evaluating the sliding motion.