PET CT in aortic disease

PET CT in aortic disease

Positron emission tomography using fluorodeoxyglucose is useful in detecting areas of high metabolic activity as in case of inflammatory cells and malignant cells. Aortic inflammation in diseases like aortoarteritis (Takayasu arteritis) and giant cell arteritis can be picked up by PET computed tomography imaging. It may also be able to detect inflammatory activity in aortic endovascular stent graft infection.

PET CT is also useful in the evaluation of acute aortic syndromes like aortic dissection, penetrating atherosclerotic ulcer and intramural hematoma as well as aortic aneurysms, atherosclerotic lesions and aortic tumors [1]. But it may be noted that the long time delay of 60 minutes from the administration of FDG and starting of scan is not acceptable in most acute aortic syndromes in which early surgical intervention is required. But it is useful in differentiating acute from chronic dissection.

There is elevated metabolic activity at the site of fresh laceration in the aortic intima which may induce repair mechanisms leading to activation of macrophages and myofibrinocytes in the vessel wall enhancing FDG uptake [1]. Intramural hematomas and penetrating atherosclerotic ulcers also have increased FDG uptake, though PET CT is not usually the primary investigatory modality in these cases as well as they present as acute aortic syndromes.

Reference

1. Kim J, Song HC. Role of PET/CT in the Evaluation of Aortic Disease. Chonnam Med J. 2018 Sep;54(3):143-152.