Pulmonary artery involvement in Takayasu arteritis. PET/CT versus CT angiography.
OBJECTIVE
To report a patient with Takayasu arteritis in whom 18F-Fluorodeoxyglucose (FDG) positron emission tomography (PET)/computerised tomography (CT) failed to demonstrate pulmonary artery involvement.


METHODS
A patient with Takayasu arteritis underwent PET/CT and CT angiography before and one year after immunosuppressive treatment.


RESULTS
Before treatment, PET/CT showed increased FDG uptake in the aortic arch and epiaortic arteries; pulmonary arteries were not visualised. Follow-up PET/CT one year later demonstrated resolution of abnormal vascular FDG uptake. CT angiography of the chest/abdomen prior to treatment revealed circumferential thickening of the ascending aorta, aortic arch, supra-aortic branches, and left inferior intralobar pulmonary artery with normal lumen diameter (27 mm). After therapy, CT angiography revealed decreased aortic wall thickening with complete resolution of intralobar wall thickening. However, the lumen of the central pulmonary artery was increased (32 mm).


CONCLUSIONS
PET/CT is very sensitive in depicting active vasculitis, but cannot visualise the pulmonary arteries, presumably because their diameter is below the power of detection of PET/CT. CT angiography or magnetic resonance angiography is required to evaluate pulmonary artery abnormalities.
Rheumatology Unit, Azienda Ospedaliera di Reggio Emilia, IRCCS, Reggio Emilia, Italy.
O
O
Addimanda
L
L
Spaggiari
N
N
Pipitone
A
A
Versari
P
P
Pattacini
C
C
Salvarani
D000328:Adult; D001013:Aorta, Thoracic / Q000000981:diagnostic imaging; D001027:Aortography; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D007166:Immunosuppressive Agents / Q000627:therapeutic use; D064847:Multimodal Imaging; D049268:Positron-Emission Tomography; D011237:Predictive Value of Tests; D011651:Pulmonary Artery / Q000000981:diagnostic imaging*; D019275:Radiopharmaceuticals; D012680:Sensitivity and Specificity; D013625:Takayasu Arteritis / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000188:drug therapy; D013997:Time Factors; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome; D051598:Whole Body Imaging
D007166:Immunosuppressive Agents; D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18