Evaluation of Azygous Vein Aneurysm Using Integrated PET/MRI

A previously healthy, non-smoking, 72-year-old woman was referred to our hospital with abnormal chest X-ray and chest discomfort. A 3.5-cm, well-defined, right paratracheal mass was revealed on non-contrast chest computed tomography (CT), which was suspected to be an azygous vein aneurysm, lymph adenopathy or neurogenic tumor. Whole-body integrated positron emission tomography/magnetic resonance imaging (PET/MRI) (Biograph mMR; Siemens Healthcare, Erlangen, Germany) was performed for the differential diagnosis. A homogenously enhancing mass connected with the azygous vein was well visualized in a post-contrast volumetric interpolated gradient echo (VIBE) sequence (Fig. 1). Additionally, the PET showed minimal ¹⁸F-fluorodeoxyglucose (FDG) uptake (maximum standardized uptake value [SUVmax], 1.83), similar to that of the great vessels, with no filling defect to suggest thromboembolism and no significant FDG uptake to suggest active thromboembolism or malignancy. The imaging findings in integrated PET/MRI were useful to characterize azygous vein aneurysm [1, 2]. The patient had a video-assisted thoracoscopic surgery to relieve the symptom of chest pain. A congenital etiology of azygous vein aneurysm was confirmed by pathology.

Fig. 1.

Whole-body integrated PET/MRI of the 72-year-old woman patient revealing a 3.5-cm, well-demarcated mass connected with azygous vein. This mass was surgically removed (bottom row). VIBE volumetric interpolated gradient echo, HASTE half-Fourier acquisition single-shot turbo spin echo, T1 TSE T1-weighted turbo spin echo, FS fat suppressed