Relationship between fluorodeoxyglucose uptake in the large vessels and late aortic diameter in giant cell arteritis.
OBJECTIVE
GCA carries an increased risk of developing thoracic aortic aneurysms. Previous work with fluorodeoxyglucose (FDG)-PET has shown that the aorta is frequently involved in this type of vasculitis. We wanted to investigate whether there is a correlation between the extent of vascular FDG uptake during the acute phase of GCA and the aortic diameter at late follow-up.


METHODS
All patients with biopsy-proven GCA who ever underwent an FDG-PET scan in our centre were asked to undergo a CT scan of the aorta. The diameter of the aorta was measured at six different levels (ascending aorta, aortic arch, descending aorta, abdominal suprarenal, juxtarenal and infrarenal aorta) and the volumes of the thoracic and of the abdominal aorta were calculated.


RESULTS
Forty-six patients agreed to participate (32 females, 14 males). A mean of 46.7 +/- 29.9 months elapsed between diagnosis and CT scan. All aortic dimensions were significantly smaller in women than in men, except for the diameter of the ascending aorta. Patients who had an increased FDG uptake in the aorta at diagnosis of GCA, had a significantly larger diameter of the ascending aorta (P = 0.025) and descending aorta (P = 0.044) and a significantly larger volume of the thoracic aorta (P = 0.029). In multivariate analysis, FDG uptake at the thoracic aorta was associated with late volume of the thoracic aorta (P = 0.039).


CONCLUSIONS
GCA-patients with increased FDG uptake in the aorta may be more prone to develop thoracic aortic dilatation than GCA patients without this sign of aortic involvement.
Department of Internal Medicine, Gasthuisberg University Hospital, Herestraat 49, 3000 Leuven, Belgium. daniel.blockmans@uz.kuleuven.ac.be
D
D
Blockmans
W
W
Coudyzer
S
S
Vanderschueren
S
S
Stroobants
D
D
Loeckx
S
S
Heye
L
L
De Ceuninck
G
G
Marchal
H
H
Bobbaers
D000368:Aged; D000369:Aged, 80 and over; D001011:Aorta / Q000000981:diagnostic imaging / Q000473:pathology*; D001012:Aorta, Abdominal / Q000000981:diagnostic imaging / Q000473:pathology; D001013:Aorta, Thoracic / Q000000981:diagnostic imaging / Q000473:pathology; D001027:Aortography; D004108:Dilatation, Pathologic / Q000000981:diagnostic imaging; D005260:Female; D019788:Fluorodeoxyglucose F18; D005500:Follow-Up Studies; D013700:Giant Cell Arteritis / Q000000981:diagnostic imaging* / Q000473:pathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals; D012008:Recurrence; D012307:Risk Factors; D012737:Sex Factors; D014057:Tomography, X-Ray Computed
D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18