PET Imaging May Help Estimate Aneurysm Risk in Giant Cell Arteritis Patients

A cohort study of 106 persons with giant cell arteritis (GCA) who underwent FDG- PET imaging found that higher total vascular score (TVS) was associated with greater yearly increase in thoracic aortic dimensions. The authors suggest that performing PET imaging at diagnosis may help to estimate the risk for aortic aneurysm formation in these patients. The study is published in Annals of Internal Medicine.

GCA is a large vessel vasculitis that preferentially affects the cranial arteries and the aorta and its proximal branches. Early imaging is recommended for diagnosis of GCA. Two severe complications of GCA are sudden irreversible vision loss and aortic aneurysm formation and dissection. FDG PET imaging may be used for the assessment of large vessel vasculitis; however, previous retrospective research has indicated that FDG uptake in large vessels at diagnosis increases the risk for aortic complications.

Researchers from University Hospitals Leuven, Leuven, Belgium prospectively studied 106 patients with GCA and FDG PET imaging 3 days or less after initiation of glucocorticoids to measure the association between vascular FDG uptake at diagnosis and the change in aortic dimensions. Participants had PET and computed tomography (CT) imaging at diagnosis and CT imaging yearly for a maximum of 10 years. The authors report that compared with patients with a negative PET scan result, those with a positive scan result had experienced aortic dimension and volume changes associated with TVS. They also report that patients with a positive PET scan result had a higher risk for thoracic aortic aneurysms. According to the authors, their study confirms that vascular FDG uptake is an independent predictor of the development of thoracic aortic aneurysms with a higher increase in thoracic aortic diameters and volume in patients with higher TVS.