11C-Acetate PET Imaging in Patients with Multiple Sclerosis

Abstract

BackgroundActivation of glial cells is a cardinal feature in multiple sclerosis (MS) pathology, and acetate has been reported to be selectively uptaken by astrocytes in the CNS. The aim of this study was to investigate the efficacy of PET with 11C-acetate for MS diagnosis.Materials and MethodsSix patients with relapsing-remitting MS and 6 healthy volunteers (HV) were enrolled. The 11C-acetate brain uptake on PET was measured in patients with MS and HV. Volume-of-interest analysis of cerebral gray and white matter based on the segmentation technique for co-registered MRI and voxel-based statistical parametric analysis were performed. Correlation between 11C-acetate uptake and the lesion number in T1- and T2- weighted MR images were also assessed.ResultsThe standardized uptake value (SUV) of 11C-acetate was increased in both white and gray matter in MS patients compared to HV. Voxel-based statistical analysis revealed a significantly increased SUV relative to that in the bilateral thalami (SUVt) in a broad area of white matter, particularly in the subcortical white matter of MS patients. The numbers of T2 lesions and T1 black holes were significantly correlated with SUV of 11C-acetate in white and gray matter.ConclusionsThe 11C-acetate uptake significantly increased in MS patients and correlated to the number of MRI lesions. These preliminary data suggest that 11C-acetate PET can be a useful clinical examination for MS patients.

Chronic inflammation in multiple sclerosis — seeing what was always there

“…Acetate is a potential ligand for astrocyte PET, as it is relatively selectively metabolized by astrocytes in the CNS. In a small pilot application, 11 C-acetate uptake in the bilateral thalami and diffusely in the white matter was shown to be greater in the brains of people with MS than in the brains of healthy controls 137 . The numbers of T2 lesions and T1 black holes correlated with the 11 C-acetate uptake, suggesting that this measure is a relevant index of inflammatory pathology.…”

“…• Leptomeningial enhancement on T2-FLAIR MRI with gadolinium contrast 116,118,120 Innate immune inactivation • Translocator protein (TSPO) PET 124,125,127,128,130 • 11 C-acetate PET 137 • Myo-inositol proton magnetic resonance spectroscopy [142][143][144]…”

Astrocyte metabolism in multiple sclerosis investigated by 1-C-11 acetate PET

“…We have reported higher brain accumulation of 1-C-11 acetate in patients with MS than in NC subjects 20-40 min after administration of the compound, using static PET. 7 This phenomenon was speculated as being reflective of the increased extraction of 1-C-11 acetate observed in this study. The present study had limitations.…”

Molecular and Metabolic Imaging in Multiple Sclerosis

“…An increased uptake of this radioligand was observed in both the WM and the GM of MS patients when compared to controls, but was more pronounced in the WM, particularly in the regions of axonal damage, as detected by diffusion-tensor imaging MRI. 77 Therefore, the detection of acetate has been suggested as a marker of astrocytic-associated damage in MS, although a development of a clinically feasible protocol for acetate PET and future investigations are warranted.…”

“…3) lack of standardized procedures (there is a need for data modelling techniques based on methods not dependent on reference plasma input or manual delineation of reference tissue region); 54 4) relatively low resolution of PET with subsequent difficulties in evaluating small plaques; 77 5) static image acquisition in most protocols with subsequent difficulties in tracking the tracer over time.…”