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Background18F-Flutemetamol (18F-FMM) PET/CT imaging has been widely applied to the diagnosis of mild cognitive impairment and Alzheimer's disease.PurposeThis study aims to explore the distributions of 18F-FMM in different brain regions of mild cognitive impairment (MCI) and Alzheimer's disease (AD) patients and the factors that may affect the combination of 18F-FMM, evaluating the use of 18F-FMM PET/CT imaging in the diagnosis of MCI and AD patients.MethodsFrom July 2020 to April 2021, 24 subjects with MCI (12 males, 12 females, aged of (70.54±9.27) years old), 25 subjects with AD (11 males, 14 females, aged (70.56±7.30) years old) and 9 subjects as normal controls (NC, 2 males, 7 females, aged (57.67±9.00) years old) were recruited from Shanghai. The 18F-FMM PET/CT brain imaging of all subjects were qualitatively and semi-quantitatively analyzed by visual evaluation and standardized uptake value ratio (SUVR), respectively. Student's t-test, one-way analysis of variance and rank sum test were used for the comparison of quantitative variables. Pearson's chi-squared test and Fisher's exact test were used for the comparison of qualitative variables. The diagnostic efficiency was obtained by ROC curve. Multiple linear regression analysis was used to analyze the factors that might affect the combination of 18F-FMM.ResultsThe positive rate of visual assessment was significantly different in NC, MCI and AD groups (χ2=26.85, p < 0.001), and significant differences existed statistically in SUVR of all brain regions among the three groups (H value: 11.54~19.34, F value: 7.43, 11.48, all p < 0.01). The mean values of SUVR in the whole brain of the three groups were statistically different (Z value: -3.87, -2.79, -2.45, all p < 0.016 7). Compared with MCI group, the positive rate in occipital lobe, temporal lobe, parietal lobe and posterior cingulate gyrus was statistically significant (χ2=7.53~10.89, all p < 0.01). With respect to NC, SUVR of all brain regions was lower than that in AD, while SUVR of temporal lobe, frontal lobe and precuneu were lower than that in MCI. Meanwhile, SUVR of occipital lobe, temporal lobe, frontal lobe and parietal lobe in MCI were lower than that in AD. Receiver operating characteristic (ROC) curves showed that the SUVR value of temporal lobe and the mean value of SUVR in the whole brain had the ability to distinguish NC, MCI and AD in sequence. Multiple linear regression analysis showed that cognitive level was significantly negatively correlated with 18F-FMM SUVR in different brain regions.Conclusion18F-FMM PET/CT brain imaging could reflect the cognitive level of middle-aged and elderly people intuitively and has clear diagnostic value for MCI and AD.

BackgroundSubjective cognitive decline (SCD) and mild cognitive impairment (MCI) are a transitional state between normal aging and mild dementia, and most of them have potential Alzheimer's Disease (AD) pathology. Studying the pathophysiological characteristics of SCD and MCI is helpful to the early diagnosis of AD.PurposeThis study aims to investigate the brain perfusion differences among SCD, MCI and AD, and to evaluate the application value of brain perfusion SPECT/CT imaging combined with NeuroGamTM software in these diseases.MethodsFrom July 2020 to April 2021, 15 patients with SCD, 29 patients with MCI and 36 patients with AD were collected from several general hospitals in Shanghai. All subjects underwent neuropsychological test and 99mTc-ECD brain perfusion SPECT/CT imaging. The perfusion levels of Brodmann areas (BA) in the three groups were semi-quantitatively analyzed by NeuroGamTM, and compared with normal database. Student's t-test, one-way analysis of variance and rank sum test were used for the comparison of quantitative variables. Pearson's chi-squared test was used for the comparison of qualitative variables.ResultsThere is no significant difference in BA 4~11, 17~25, 28, 31~32, 36~40 and 44~47 between SCD group and MCI group. The mean perfusion values of BA 8-right(R), 20-left(L), 21R, 23L, 23R, 24L, 31L, 38L, 38R and 45R in SCD group are significantly higher than those in AD group (p

Nuclear medicine single photon emission computed tomography (SPECT) is a widely installed and used equipment in nuclear medicine department, which can reflect the changes of physiological, biochemical, functional and metabolic in vivo. SPECT has diverse tracers but lower special resolving power, while X-ray computed tomography (CT) has high resolution of tissue morphology. SPECT/CT combines functional imaging with structural anatomy, hence is widely used in the diagnosis and treatment of various diseases with high sensitivity and specificity. It has become a clinically recognized routine examination item and provides important information for clinical diagnosis and treatment. With the popularization of SPECT in hospitals at all levels in Shanghai, a standardized reporting format is needed. In order to provide high quality SPECT reports and provide a basis for clinical work, scientific research and teaching, standard elemental specification for SPECT imaging report was proposed to meet the mutual recognition of image report as required by National Health Commission of the People's Republic of China. According to the international guidelines and previous experience, the expert committee of Shanghai nuclear medicine quality control center has formulated the elements and specifications of SPECT imaging report in Shanghai, which provides a reference standard for SPECT imaging report.

Radium-223 dichloride (223Ra) (Sofigo), a calcium-mimetic agent that specifically targets bone lesions, was approved in 2020 by China Food and Drug Administration (CFDA) to treat castration‑resistant prostate cancer and bone metastases (CRPC) with symptomatic bone metastases and no known visceral metastatic diseases. It is the fisrt α particles targeted radiopharmaceutical therapeutic drugs in the world to be applied to CRPC with bone metastase (mCRPC) patients. In recent years, the application of nuclear medicine technology to evaluate the efficacy of 223Ra in the treatment of mCRPC patients abroad has been very common, but only few hospitals in China have entered the stage of clinical application. In order to provide clear recommendations for clinical applications of radionuclide imaging in evaluating the efficacy of 223Ra in the treatment of mCRPC, a survey of recent progress is carried out in this study, and public available clinical data of single photon emission computed tomography/computed tomography (SPECT/CT), and positron emission tomography/computed tomography (PET/CT) using radiolabeled chemical agents worldwide in the evaluation of 223Ra treatment for patients with CRPC and bone metastase,are presented and commented.

Purpose: Noninvasive methods used in clinic to accurately detect DA neuron loss in diabetic brain injury and diabetic retinopathy have not been reported up to now. 18F-FP-CIT is a promising dopamine transporter (DAT) targeted probe. Our study first applies 18F-FP-CIT PET imaging to assess DA neuron loss in the striatum and retina of T1DM rat model. Methods: T1DM rat model was induced by a single intraperitoneal injection of streptozotocin (STZ) (65 mg kg−1, ip). 18F-FP-CIT uptake in the striatum and retina was evaluated at 4 weeks, 8 weeks and 12 weeks after STZ injection. The mean standardized uptake value (SUVmean) and the maximum standardized uptake value (SUVmax) were analyzed. Western blot was performed to confirm the DAT protein levels in the striatum and retina. Results: PET/CT results showed that the SUV of 18F-FP-CIT was significantly reduced in the diabetic striatum and retina compared with the normal one from 4-week to 12-week (p < 0.0001). Western blots showed that DAT was significantly lower in the diabetic striatum and retina compared to the normal one for all three time points (p < 0.05). The results from Western blots confirmed the findings in PET imaging studies. Conclusions: DA neuron loss in the striatum and retina of T1DM rat model can be non-invasively detected with PET imaging using 18F-FP-CIT targeting DAT. 18F-FP-CIT PET imaging may be a useful tool used in clinic for DR and diabetic brain injury diagnosis in future. The expression level of DAT in striatum and retina may act as a new biomarker for DR and diabetic brain injury diagnosis. [ABSTRACT FROM AUTHOR]

Objective: The aim was to study whether the computed tomography (CT) density and β-amyloid (Aβ) level of intraorbital optic nerve could assist in diagnosing mild cognitive impairment (MCI) and Alzheimer's disease (AD). Methods: A total of sixty subjects were recruited in our study, including nine normal control (NC) subjects (i.e., 4 men and 5 women), twenty four MCI subjects (i.e., 11 men and 13 women), and twenty seven AD subjects (i.e., 14 men and 13 women). All subjects conducted 18F-flutemetamol amyloid positron emission tomography (PET)/CT imaging. Blinded to the clinical information of the subjects, two physicians independently measured and calculated the standardized uptake value ratio (SUVR) of the bilateral occipital cortex, SUVR of the bilateral intraorbital optic nerve, and CT density of the bilateral intraorbital optic nerve by using GE AW 4.5 Workstation. Results: Between AD and NC groups, the differences of the bilateral intraorbital optic nerve SUVR were statistically significant; between AD and MCI groups, the differences of the left intraorbital optic nerve SUVR were statistically significant. Between any two of the three groups, the differences in the bilateral intraorbital optic nerve density were statistically significant. The bilateral occipital SUVR was positively correlated with the bilateral intraorbital optic nerve SUVR and negatively correlated with the bilateral intraorbital optic nerve density. Bilateral intraorbital optic nerve SUVR was negatively correlated with the bilateral intraorbital optic nerve density. The area under the receiver operating characteristic (ROC) curve of multiple logistic regression was 0.9167 (for MCI vs. NC) and 0.8951 (for AD vs. MCI). The Montreal Cognitive Assessment (MoCA) and Mini-Mental State Examination (MMSE) scores were positively associated with the intraorbital optic nerve density and were negatively associated with the intraorbital optic nerve SUVR. The regression equation of MoCA was y = 16.37-0.9734 × x 1 + 0.5642 × x 2-3.127 × x 3 + 0.0275 × x 4; the R 2 was 0.848. The regression equation of MMSE was y = 19.57-1.633 × x 1 + 0.4397 × x 2-1.713 × x 3 + 0.0424 × x 4; the R 2 was 0.827. Conclusion: The CT density and Aβ deposition of the intraorbital optic nerve were associated with Aβ deposition of the occipital cortex and the severity of cognitive impairment. The intraorbital optic nerve CT density and intraorbital optic nerve Aβ deposition could assist in diagnosing MCI and AD. [ABSTRACT FROM AUTHOR]

Purpose: Diabetic retinopathy (DR) is characterized by dopaminergic neuron loss in the retina of the eyes. [18F]fluoropropyl-(+)-dihydrotetrabenazine ([18F]FP-(+)-DTBZ) positron emission tomography (PET) has been shown to detect dopaminergic neuron loss. The study is to investigate the feasibility of PET imaging with [18F]FP-(+)-DTBZ for early diagnosis of diabetic retinopathy (DR) in diabetes mellitus (DM) rat models.Methods: The DM rat model was established by a single intraperitoneal injection of streptozotocin (STZ) (65 mg/kg). After 4 weeks, 8 weeks, and 12 weeks of STZ injection, the retinas of the rats were evaluated by electroretinogram (ERG), color fundus photography (CFP), fundus fluorescein angiography (FFA), and small animal PET scan with [18F]FP-(+)-DTBZ by targeting vesicular monoamine transporter 2 (VMAT2). [18F]FP-(+)-DTBZ uptake in retina was quantified as standardized uptake value (SUV). Immunofluorescence staining and Western blot were also performed to confirm the expression level of VMAT2 in retina.Results: ERG dysfunction was observed at 8 weeks in STZ-diabetic rats, evidenced by smaller amplitudes of oscillatory potentials (OPs) when compared with OPs in normal rats. CFP and FFA showed no significant difference in vascular leakage and neovascularization between STZ-diabetic retinas and normal ones until 8 weeks. PET imaging revealed that the SUV of [18F]FP-(+)-DTBZ was significantly lower in the STZ-diabetic retinas compared with the normal ones as early as of week 4. The results from immunofluorescence staining and Western blots confirmed the early findings in PET imaging studies.Conclusions: Early DR can be non-invasively detected with PET imaging using [18F]FP-(+)-DTBZ targeting VMAT2. The expression level of VMAT2 in retina may act as a new biomarker for early DR diagnosis. [ABSTRACT FROM AUTHOR]