The value of FDG-PET in the diagnosis of thromboangiitis obliterans--a case series.

Thromboangiitis obliterans (TAO) is an inflammatory vascular disease affecting dominantly the vessels of the extremities and is etiologically strongly associated with tobacco consumption. Different imaging techniques are generally used to exclude potential differential diagnoses. We investigated the value of (18) F-flourodeoxyglucose positron emission tomography ([(18) F]FDG-PET) in the diagnosis of TAO. All consecutive patients with diagnosed TAO between Nov 2001 and Nov 2003 at our institution who underwent [(18) F]FDG-PET in the diagnostic workup were analyzed retrospectively. Whole-body scans were conducted after a fasting period of at least 6 h and blood glucose levels lower than 180 mg/dl. The primary endpoint was defined as significantly increased vascular FDG uptake. Tracer uptake was visually determined and, in accordance with strength, divided into grades 0 to 3. In total, ten patients were statistically evaluated. The median patient age at the date of the first [(18) F]FDG-PET was 41.5 years. Repetitive FDG-PET imaging was performed in seven out of ten patients (70 %). The endpoint was objectified in one of the initial examinations (10 %) and in another one out of seven follow-up scans (14.3 %). One positive [(18) F]FDG-PET was observed in the pelvic vessels and the other in the infrapopliteal arteries. Therefore, increased tracer uptake could be observed in two examinations on two different patients (both with grade 3 tracer uptake) out of 17 conducted [(18) F]FDG-PETs in total. The [(18) F]FDG-PET was not a suitable investigative procedure for the diagnosis of TAO in the present patient cohort.