PET image reconstruction is challenging due to the ill-poseness of the inverse problem and limited number of detected photons. Recently deep neural networks have been widely and successfully used in computer vision tasks and attracted growing interests in medical imaging. In this work, we trained a deep residual convolutional neural network to improve PET image quality by using the existing inter-patient information. An innovative feature of the proposed method is that we embed the neural network in the iterative reconstruction framework for image representation, rather than using it as a post-processing tool. We formulate the objective function as a constrained optimization problem and solve it using the alternating direction method of multipliers (ADMM) algorithm. Both simulation data and hybrid real data are used to evaluate the proposed method. Quantification results show that our proposed iterative neural network method can outperform the neural network denoising and conventional penalized maximum likelihood methods.

BackgroundAlzheimer’s disease (AD) is the most common cause of dementia. However, none of medical treatment can stop or reverse the underlying neurodegenerative of AD at present. Acupuncture has attracted more and more attention in recent years due to its efficacy and very few side effects. Lately, a systematic review has thought that the evidence on the effectiveness of acupuncture in improving the cognitive function of AD patients was not powerful enough. Therefore, the aim of this study is to explore the efficacy and safety of acupuncture in patients with mild to moderate AD.MethodsThis was a randomized, controlled, parallel-group, exploratory study with 4-week baseline (T0), 12-week treatment phase (T1) and 12-week follow-up period (T2). Patients with mild to moderate AD meeting the included criteria were randomly allocated into either acupuncture or donepezil hydrochloride groups. The acupuncture group(AG) was given acupuncture treatment three times per week and the donepezil hydrochloride group(DG) group was administered donepezil hydrochloride once daily (5 mg/day for the first 4 weeks and 10 mg/day thereafter). Primary efficacy was measured using Alzheimer’s disease Assessment Scale-Cognitive (ADAS-cog) and Clinician’s Interview-Based Impression of Change-Plus (CIBIC-Plus). The second outcomes were measured with 23-Item Alzheimer’s disease Cooperative Study Activities of Daily Living Scales (ADAS-ADL23) and Neuropsychiatric Index (NPI).ResultsOf 87 participants enrolled in the study, 79 patients finished their treatment and follow-up processes. The ADAS-cog scores for AG group showed obvious decreases at T2 and ∆(T2-T0)when compared with DG group, and significant between-group differences were detected (all p < 0.05). The mean CIBIC-Plus values for the AG group at T1 and T2 were much lower than that for the DG group, and there were significant differences between the two groups (푃<0.05). There were no significant between-group differences in the scores of ADAS-ADL23 and NPI during the study period. Treatment discontinuations due to adverse events were 0 (0%) and 4 (9.09%) for the AG and DG groups, respectively.ConclusionsAcupuncture is safe, well tolerated and effective in improving the cognitive function, global clinical status of AD.Trial Registration ChiCTR-IOR-17010465 (Retroactively registered on 18 JAN 2017).

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Three conjugates based on dendrimer PAMAM generation five were synthesized and radiolabeled successfully. To investigate their tumor targeting, the in vitro and in vivo stability, cell uptake, in vivo biodistribution, and micro-SPECT imaging were evaluated, respectively. The conjugate of (99m)Tc labeled PEGylated dendrimer PAMAM folic acid conjugate ((99m)Tc-G5-Ac-pegFA-DTPA) shows much higher uptake in KB cancer cells and accumulated more in the tumor area than that of the other two conjugates. The uptake in KB cells depends on the incubation time. The results of in vivo biodistribution agree with the data obtained from micro-SPECT imaging. These studies show that PEGylation of PAMAM dendrimer folic acid conjugate improves the tumor targeting. Folate-conjugated dendrimer maybe developed to be potential radiopharmaceuticals and targeted drug delivery systems.