Carotid plaque inflammatory activity assessed by 2-[18F]FDG-PET imaging decrease after a neurological thromboembolic event

Fig. 1. Schematic example of the calculated average max standardized uptake value (aSUVmax) and grayscale median (GSM). ECA = external carotid artery. ICA = internal carotid artery. CCA = common carotid artery. The 3D ultrasound acquisition of the plaque was sliced in 2-mm segments from the flow divider, and the slice containing the maximum plaque thickness was identified. The slice with the maximum plaque thickness and the two slices on each side were used in analyses. For the PET/CT, the flow divider was used as landmark for alignment of SUVmax readings to the ultrasound readings. An average SUVmax was calculated for this 1 cm long plaque volume. GSM was automatically calculated by the software for the volume of the 10-mm-long plaque segment

Fig. 2. Flowchart of the included patients. Of the 19 included four were excluded. Two were excluded after withdrawal of consent, one died because of an, at the time of inclusion, undiagnosed cancer and one scan was lost

Fig. 3. Change in average maximum standardized uptake values (aSUVmax) from baseline to follow-up. The black diamonds represent the mean aSUVmax at baseline and follow-up with the 95% confidence interval as the dotted line. Mean difference in aSUVmax of − 0.18, CI95%: − 0.34 to − 0.02, P = 0.034. The light blue lines represent each patient with the circles marking the aSUVmax at baseline and follow-up. The patient with recurrent symptoms undergoing carotid endarterectomy before the follow-up scan is marked as a filled circle

Fig. 4. Baseline and follow-up patient example of 2-[18F]FDG-PET / CT-angiography and ultrasound images. Images from one patient. To the left 2-[18F]FDG-PET/CT angiography fusion, frontal MPR and to the right ultrasound images, axial plane. The top images are from baseline and the bottom follow-up. The white arrow points to the plaque on the symptomatic side