No abstract

Background:The acute stress secretagogue PACAP leads to catecholamine release, but the source of calcium necessary for secretion is unknown. Results: PACAP stimulation increases LVA Ca v 3.2 influx in a PKC-dependent process. Conclusion: PACAP-mediated acute sympathetic stress functionally recruits a pool of latent Ca v 3.2 channels to supply calcium for secretion. Significance: Native sympathoadrenal stimulation elicits catecholamine release through a non-canonical mechanism.

Purpose Establishing reliable methods for interpreting elevated cerebral amyloid-β plaque on PET scans is increasingly important for radiologists, as availability of PET imaging in clinical practice increases. We examined a three-step method to detect plaque in cognitively normal older adults, focusing on the additive value of quantitative information during the PET scan interpretation process. Methods Fifty-five F-18 florbetapir PET scans were evaluated by three experienced raters. Scans were first visually interpreted as having “elevated” or “non-elevated” plaque burden (“Visual Read”). Images were then processed using a standardized quantitative analysis software (MIMneuro) to generate whole brain and region of interest (ROI) standard uptake value ratios (SUVRs). This “Quantitative Read” was considered elevated if at least two of six ROIs had an SUVR >1.1. The final interpretation combined both visual and quantitative data together (“VisQ Read”). Cohen’s kappa values were assessed as a measure of interpretation agreement. Results Plaque was elevated in 25.5–29.1% of the 165 total Visual Reads. Inter-rater agreement was strong (Kappa=0.73–0.82) and consistent with reported values. Quantitative Reads were elevated in 45.5% of participants. Final VisQ Reads changed from initial Visual Reads in 16 (9.7%) interpretations, with most changing from “non-elevated” Visual Reads to “elevated.” These changed interpretations demonstrated lower plaque quantification than those initially read as “elevated” that remained unchanged. Inter-rater variability improved for VisQ Reads with the addition of quantitative information (Kappa=0.88–0.96). Conclusion Inclusion of quantitative information increases consistency of PET scan interpretations for early detection of cerebral amyloid-β plaque accumulation.

DBT and FFDM mammograms more frequently include posterior or lateral tissue, the inframammary fold on MLO views, the pectoralis muscle on CC views, and skin folds than FS mammograms. Inclusion of more breast tissue with newer technologies suggests traditional positioning standards, in conjunction with updated standardized positioning training, are still applicable at the expense of including more skin folds.

Na(18)F PET/CT is the most comprehensive imaging modality for the evaluation of osseous metastatic disease. Although further data acquisition is necessary to expand cost-benefit analyses of this imaging agent, emerging data reinforce its diagnostic advantage, suggest methods to mitigate impediments to broader utilization of Na(18)F PET/CT, and introduce a potentially viable technique for single-session combined Na(18)F and FDG PET/CT staging of soft-tissue and osseous disease.