In Alzheimer disease (AD), neuroinflammation is an important process related to the deposition of beta-amyloid plaques and the activation of microglia. The inflammatory process can occur in both the gray matter and the white matter. We evaluated glucose metabolism of the white matter in AD patients and compared the value with cognitive parameters of the patients. Eighteen AD patients and 18 healthy subjects underwent F-18 fluorodeoxyglucose (FDG) and F-18 florbetaben positron emission tomography (PET). After segmentation of the white matter in both PET images, the specific binding ratio (SBR) of the global and regional cerebral white matter was checked. We evaluated the differences in SBR of the global and regional white matter between AD patients and healthy subjects. Then, we assessed the correlation between SBR and cognitive parameters in AD patients. In F-18 FDG PET images, the global white matter SBR was significantly higher in AD patients than in healthy subjects. In the regional analysis, the white matter SBR was significantly higher for the frontal, temporal, and parietal areas in AD patients. In the correlation analysis with F-18 FDG PET, SBR was significantly correlated with the Global Deterioration Scale, Mini-Mental State Examination scores, and amyloid deposition. Glucose metabolism of the white matter was significantly higher in AD patients than in healthy subjects and it was related to the scores of cognitive parameters. We suggest that F-18 FDG PET, like 18-kDa translocator protein PET, could be used as an indicator of neuroinflammation; however, further research is needed for a direct comparison between the 2 tests.

Although amyloid beta (Aβ) imaging is widely used for diagnosing and monitoring Alzheimer’s disease in clinical fields, paralleling comparison between ¹⁸F-flutemetamol and ¹⁸F-florbetaben was rarely attempted in AD mouse model. We performed a comparison of Aβ PET images between ¹⁸F-flutemetamol and ¹⁸F-florbetaben in a recently developed APPswe mouse model, C57BL/6-Tg (NSE-hAPPsw) Korl. After an injection (0.23 mCi) of ¹⁸F-flutemetamol and ¹⁸F-florbetaben at a time interval of 2–3 days, we compared group difference of SUVR and kinetic parameters between the AD (n = 7) and control (n = 7) mice, as well as between ¹⁸F-flutemetamol and ¹⁸F-florbetaben image. In addition, bio-distribution and histopathology were conducted. With visual image and VOI-based SUVR analysis, the AD group presented more prominent uptake than did the control group in both the ¹⁸F-florbetaben and ¹⁸F-flutemetamol images. With kinetic analysis, the ¹⁸F-florbetaben images showed differences in K1 and k4 between the AD and control groups, although ¹⁸F-flutemetamol images did not show significant difference. ¹⁸F-florbetaben images showed more prominent cortical uptake and matched well to the thioflavin S staining images than did the ¹⁸F-flutemetamol image. In contrast, ¹⁸F-flutemetamol images presented higher K1, k4, K1/k2 values than those of ¹⁸F-florbetaben images. Also, ¹⁸F-flutemetamol images presented prominent uptake in the bowel and bladder, consistent with higher bio-distribution in kidney, lung, blood and heart. Compared with ¹⁸F-flutemetamol images, ¹⁸F-florbetaben images showed prominent visual uptake intensity, SUVR, and higher correlations with the pathology. In contrast, ¹⁸F-flutemetamol was more actively metabolized than was ¹⁸F-florbetaben (Son et al. in J Nucl Med 58(Suppl 1):S278, 2017 ].

A benign osteoblastoma of the nasal cavity is very rare. A 57-year-old woman, who had a radical hysterectomy for carcinoma of the uterine cervix 5 years ago, underwent F-18 FDG PET/CT. An expansile bone tumor with high glucose metabolism in the middle turbinate of the left nasal cavity was incidentally demonstrated. A subsequent Tc-99m methylene diphosphonate 3-phase bone scan revealed focal increased uptake of radionuclide in all 3 phases at the corresponding tumor. Histology confirmed a benign osteoblastoma that was composed of proliferating osteoblasts with woven bone spicules and rich vascular stroma. Scintigraphic findings, including F-18 FDG PET/CT and 3-phase bone scan, reflected the pathologic features well.

Objective: Amyloid positron emission tomography (PET) with F-18 florbetaben (FBB), F-18 flutemetamol (FMM), and F-18 florapronol (FPN) is being used clinically for the evaluation of dementia. These radiopharmaceuticals are commonly used to evaluate the accumulation of beta-amyloid plaques in the brain, but there are structural differences between them. We investigated whether there are any differences in the imaging characteristics. Methods: A total of 605 subjects were enrolled retrospectively in this study, including healthy subjects (HS) and patients with mild cognitive impairment or Alzheimer’s disease. Participants underwent amyloid PET imaging using one of the three radiopharmaceuticals. The PET images were analyzed visually and semi-quantitatively using a standardized uptake value ratio (SUVR). In addition, we calculated and compared the cut-off SUVR of the representative regions for each radiopharmaceutical that can distinguish between positive and negative scans. Results: In the negative images of the HS group, the contrast between the white matter and the gray matter was high in the FMM PET images, while striatal uptake was relatively higher in the FPN PET images. The SUVR showed significant differences across the radiopharmaceuticals in all areas except the temporal lobe, but the range of differences was relatively small. Accuracy levels for the global cut-off SUVR to discriminate between positive and negative images were highest in FMM PET, with a value of 0.989. FBB PET also showed a high value of 0.978, while FPN PET showed a relatively low value of 0.901. Conclusions: Negative amyloid PET images using the three radiopharmaceuticals showed visually and quantitatively similar imaging characteristics except in the striatum. Binary classification using the cut-off of the global cortex showed high accuracy overall, although there were some differences between the three PET images.