18F-FDG PET in the Evaluation of Acuity of Deep Vein Thrombosis

PURPOSEF-FDG PET has been used for vascular disease, but its role in deep vein thrombosis (DVT) remains prospectively unexplored. PATIENTS AND METHODSWhole-body F-FDG PET/CT scans were performed in patients 1 to 10 weeks after onset of symptomatic DVT (n = 12) and in control subjects without DVT (n = 24). The metabolic activity (SUVmax) of thrombosed and contralateral nonthrombosed vein segments was determined. The sensitivity and specificity of F-FDG PET/CT for the diagnosis of DVT were determined by receiver operating characteristic curve analyses. In 2 patients with DVT, changes in the metabolic activity of thrombosed vein segments in serial F-FDG PET scans. RESULTSThe metabolic activity in thrombosed veins [SUVmax, 2.41 (0.75)] was visually appreciable and significantly higher than in nonthrombosed veins in either the contralateral extremity of patients with DVT [SUVmax, 1.09 (0.25), P = 0.007] or control subjects [1.21 (0.22), P < 0.001]. The area under the receiver operating characteristic curve for SUVmax was 0.9773 (P < 0.001), indicating excellent accuracy. An SUVmax threshold of greater than 1.645 was 87.5% sensitive and 100% specific for DVT. Metabolic activity in thrombosed veins correlated significantly with time from DVT symptom onset (decrease in SUVmax of 0.02/d, P < 0.05). Best-fit-line analyses suggested that approximately 84 to 91 days after acute DVT, the maximum metabolic activity of thrombosed veins would return to normal levels. CONCLUSIONSF-FDG PET/CT is accurate for detecting acute symptomatic, proximal DVT. Metabolic activity in thrombosed veins decreases with time, suggesting that F-FDG PET may be helpful in assessing the age of the clot.