Quantitative graphical analysis of simultaneous dynamic PET/MRI for assessment of prostate cancer.

Purpose: Dynamic FDG imaging for prostate cancer characterization is limited by generally small size and low uptake in prostate tumors. Our aim in this pilot study was to explore feasibility of simultaneous PET/MRI to guide localization of prostate lesions for dynamic FDG analysis using a graphical approach.

Methods: Three patients with biopsy-proven prostate cancer underwent simultaneous FDG PET/MRI, incorporating dynamic prostate imaging.

Image-guided PO2 probe measurements correlated with parametric images derived from 18F-fluoromisonidazole small-animal PET data in rats.

Unlabelled: (18)F-fluoromisonidazole PET, a noninvasive means of identifying hypoxia in tumors, has been widely applied but with mixed results, raising concerns about its accuracy. The objective of this study was to determine whether kinetic analysis of dynamic (18)F-fluoromisonidazole data provides better discrimination of tumor hypoxia than methods based on a simple tissue-to-plasma ratio.

Methods: Eleven Dunning R3327-AT prostate tumor-bearing nude rats were immobilized in custom-fabricated whole-body molds, injected intravenously with (18)F-fluoromisonidazole, and imaged dynamically for 105 min.

Positron lymphography: multimodal, high-resolution, dynamic mapping and resection of lymph nodes after intradermal injection of 18F-FDG.

Unlabelled: The lymphatic system plays a critical role in the maintenance of healthy tissues. Its function is an important indicator of the presence and extent of disease. In oncology, metastatic spread to local lymph nodes (LNs) is a strong predictor of poor outcome.

Assessment of fetal brain uptake of paraquat in utero using in vivo PET/CT imaging.

Prenatal in utero conditions are thought to play a role in the development of adult diseases including Parkinson's disease (PD). Paraquat is a common herbicide with chemical structure similar to 1-methyl-4-phenyl 1,2,3,6-tetrahydropyridine, a neurotoxin known to induce parkinsonism. In order to assess the role of in utero paraquat exposure in PD, uptake in maternal and fetal brains were measured using positron emission tomography (PET)/computed tomography (CT) imaging.

Fetal dopamine receptor characteristics assessed in utero.

Any tracer in fetal tissue comes from maternal arterial blood. Provided steady state is achieved and intermediate compartments are reversible, the Logan graphical methods should be applicable to the assessment of binding parameters in the fetal brain. Two pregnant rhesus macaques were studied with fallypride and the Logan method was used to assess dopamine receptor distribution volume ratios (DVRs) in both maternal and fetal striatum.

Fetal dose estimates for (18)F-fluoro-L-thymidine using a pregnant monkey model.

Unlabelled: Estimating the radiation dose received by the fetus from nuclear medicine procedures is important because of the greater sensitivity of rapidly developing fetal tissues to ionizing radiation. (18)F-fluoro-L-thymidine (FLT) uptake is related to cellular proliferation and is currently used to monitor tumor progression and response to therapy. This study was undertaken to estimate-on the basis of biodistribution data obtained by PET/CT in pregnant rhesus monkeys-radiation absorbed dose to a human fetus administered (18)F-FLT.

Paraquat is excluded by the blood brain barrier in rhesus macaque: An in vivo pet study.

Environmental factors have long been thought to have a role in the etiology of idiopathic Parkinson's disease (PD). Since the discovery of the selective neurotoxicity of MPTP to dopamine cells, suspicion has focused on paraquat, a common herbicide with chemical structure similar to 1-methyl-4-phenylpyridinium (MPP+), the MPTP metabolite responsible for its neurotoxicity. Although in vitro evidence for paraquat neurotoxicity to dopamine cells is well established, its in vivo effects have been ambiguous because paraquat is di-cationic in plasma, which raises questions about its ability to cross the blood brain barrier.