Uptake of F-18 FDG and ultrasound analysis of carotid plaque.

OBJECTIVES: To elucidate the relation between the echolucent plaque on carotid ultrasound and acute inflammation on F-18 FDG carotid PET/CT. METHODS: Thirty nine patients (M:F ratio = 23:16, mean age = 63 ± 11 years) that underwent coronary angiography and carotid ultrasound were divided into three groups-echolucent plaque (n = 22), calcified (n = 10), and no plaque(n = 7). All the patients underwent F-18 FDG carotid PET/CT. The mean standardized uptake values (SUV), namely target to background ratio (TBR) on 180 minutes delayed F-18 FDG carotid PET/CT images were compared with levels of serum inflammatory markers and lipid profiles, and in terms of the presence of carotid plaque on carotid US. RESULTS: 180 minutes TBR of carotid arterial wall at echolucent plaque, calcified plaque, and no plaque were 1.40 ± 0.05, 1.23 ± 0.03, 1.17 ± 0.03 in both carotid artery. TBR of carotid arterial walls for echolucent plaque were significantly larger than TBR for calcified, and no plaque respectively at the both side of carotid artery (P < .05). Serum HDL levels were found to be inversely correlated with F-18 FDG uptake at both carotid arteries (r = -0.43, P = .005) on 180 minutes delayed phase images. Also serum hs-CRP levels were found to be correlated with F-18 FDG TBR values of right carotid arteries (r = 0.41, P = .04). CONCLUSIONS: Our results show that F-18 FDG carotid PET/CT can depict metabolically active atherosclerotic plaques, and suggest that F-18 FDG carotid PET/CT can be used as a noninvasive imaging modality for functional evaluation of atherosclerosis.

A serial study of regional cerebral blood flow deficits in patients with left anterior thalamic infarction: anatomical and neuropsychological correlates.

Thalamic damage is associated with a variety of neuropsychological dysfunctions, as well as strategic infarct dementia. However, only a limited number of reports in the medical literature have discussed the correlation between the clinical findings and the specific functional changes observed on images. We investigated the neuropsychological correlation of the regional cerebral blood flow (rCBF) deficits in four patients with left anterior thalamic infarction within two days after their stroke. All of the patients showed anterograde amnesia on the verbal memory test. Some dysexecutive features were present such as decreased word fluency and an impaired performance on the Stroop test. A decreased rCBF was observed in the left supramarginal gyrus, the superior temporal gyrus, the middle and inferior frontal gyri, and the medial dorsal and anterior nuclei of the left thalamus. The changes of rCBF may have been due to remote suppression by the interruption of the thalamo-cortical circuit that connects the anterior thalamic nucleus and various cortical areas. These initial findings remained unchanged even on the follow-up studies.