(18)F-FDG PET in the evaluation of acuity of deep vein thrombosis

Abstract

Purpose: F-FDG PET has been used for vascular disease, but its role in deep vein thrombosis (DVT) remains prospectively unexplored.

Patients and methods: Whole-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.

Results: The 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.

Conclusions: F-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.

Trial registration: ClinicalTrials.gov NCT01107327.

Figures

FIGURE 1

Representative transaxial 18F-FDG PET/CT images from control subjects without DVT (left panels) and patients with DVT (right panels, white arrows).

FIGURE 2

Mean (SD) SUVmax in thrombosed and contralateral, nonthrombosed vein segments of patients with DVT (n = 12) or control subjects (n = 24). *P < 0.007 versus thrombosed vein segments. **P < 0.001 versus thrombosed vein segments.

FIGURE 3

Receiver operating characteristic curve of the SUVmax for the diagnosis of DVT by 18F-FDG PET/CT imaging.

FIGURE 4

The ratio of metabolic activity (SUVmax) in thrombosed vein segments to matching, nonthrombosed vein segments decreases with time from DVT symptom onset.

FIGURE 5

The metabolic activity of thrombosed vein segments decreases with time from DVT symptom onset. Maximum-intensity-projection images of serial 18F-FDG PET scans in a 54-year-old man with acute right lower extremity DVT involving superficial femoral, popliteal, and calf veins. PET scans were obtained 21, 35, and 70 days after DVT symptom onset. A, The metabolic activity (eg, SUVmax) was initially higher in thrombosed vein segments (black arrow) when compared with the contralateral extremity (white arrow). B, At 35 days after DVT onset, the SUVmax in thrombosed vein segments (black arrow) had declined but was still higher than matching vein segments in the contralateral, nonthrombosed extremity (white arrow). C, At 70 days, metabolic activity in thrombosed vein segments (black arrow) was barely appreciable above normal vascular activity (white arrow).

FIGURE 6

The metabolic activity of thrombosed vein segments decreases with time from DVT symptom onset. Maximum-intensity-projection images of serial 18F-FDG PET scans in a 50-year-old woman with acute left lower extremity DVT involving superficial femoral, popliteal, and calf veins. PET scans were obtained 7, 14, and 42 days after DVT symptom onset. A, The metabolic activity (eg, SUVmax) was initially higher in thrombosed vein segments (black arrow) when compared with the contralateral extremity (white arrow). B, At 14 days after DVT onset, the SUVmax in thrombosed vein segments (black arrow) had declined slightly but was still higher than matching vein segments in the contralateral, nonthrombosed extremity (white arrow) and appeared visually unchanged. C, At 42 days, metabolic activity in thrombosed veins has continued to decrease (black arrow). Metabolic activity in nonthrombosed vein segments remains low (white arrow). Note also prominent muscle activity in the calves at 42 days, likely related to recent exercise (white arrowheads).