Post-label delay times of ≥4 seconds are needed and may be combined with multidelay strategies for robust ASL assessment of CBF in Moyamoya disease.

Currently, there are no non-invasive tools to accurately diagnose wound and surgical site infections before they become systemic or cause significant anatomical damage. Fluorescence and photoacoustic imaging are cost-effective imaging modalities that can be used to noninvasively diagnose bacterial infections when paired with a molecularly targeted infection imaging agent. Here, we develop a fluorescent derivative of maltotriose (Cy7-1-maltotriose), which is shown to be taken up in a variety of gram-positive and gram-negative bacterial strains in vitro. In vivo fluorescence and photoacoustic imaging studies highlight the ability of this probe to detect infection, assess infection burden, and visualize the effectiveness of antibiotic treatment in E. coli-induced myositis and a clinically relevant S. aureus wound infection murine model. In addition, we show that maltotriose is an ideal scaffold for infection imaging agents encompassing better pharmacokinetic properties and in vivo stability than other maltodextrins (e.g. maltohexose).

Background and Purpose— Noninvasive imaging of brain perfusion has the potential to elucidate pathophysiological mechanisms underlying Moyamoya disease and enable clinical imaging of cerebral blood flow (CBF) to select revascularization therapies for patients. We used hybrid positron emission tomography (PET)/magnetic resonance imaging (MRI) technology to characterize the distribution of hypoperfusion in Moyamoya disease and its relationship to vessel stenosis severity, through comparisons with a normative perfusion database of healthy controls. Methods— To image CBF, we acquired [ 15 O]-water PET as a reference and simultaneously acquired arterial spin labeling (ASL) MRI scans in 20 Moyamoya patients and 15 age-matched, healthy controls on a PET/MRI scanner. The ASL MRI scans included a standard single-delay ASL scan with postlabel delay of 2.0 s and a multidelay scan with 5 postlabel delays (0.7–3.0s) to estimate and account for arterial transit time in CBF quantification. The percent volume of hypoperfusion in patients (determined as the fifth percentile of CBF values in the healthy control database) was the outcome measure in a logistic regression model that included stenosis grade and location. Results— Logistic regression showed that anterior ( P <0.0001) and middle cerebral artery territory regions ( P =0.003) in Moyamoya patients were susceptible to hypoperfusion, whereas posterior regions were not. Cortical regions supplied by arteries with stenosis on MR angiography showed more hypoperfusion than normal arteries ( P =0.001), but the extent of hypoperfusion was not different between mild-moderate versus severe stenosis. Multidelay ASL did not perform differently from [ 15 O]-water PET in detecting perfusion abnormalities, but standard ASL overestimated the extent of hypoperfusion in patients ( P =0.003). Conclusions— This simultaneous PET/MRI study supports the use of multidelay ASL MRI in clinical evaluation of Moyamoya disease in settings where nuclear medicine imaging is not available and application of a normative perfusion database to automatically identify abnormal CBF in patients.

In vivo Imaging of Activated Chimeric Antigen Receptor T Cells. Conflict-of-interest disclosures SSG is the founder and equity holder of CellSight Inc. that develops and translates strategies for imaging cell trafficking/transplantation. CLM holds several patent applications in the area of CAR T cell immunotherapy, is a founder of, holds equity in, and receives consulting fees from Lyell Immunopharma, has received consulting fees from NeoImmune Tech, Nektar Therapeutics and Apricity Health and royalties from Juno Therapeutics for the CD22-CAR. All other authors have declared that no conflict of interest exists. Significance ICOS-immunoPET enables in vivo imaging of activated CAR T cells at the tumor site without the need for incorporation of reporter transgenes or ex vivo biolabeling. Research.

Herein a new (11) C radiolabelling strategy for the fast and efficient synthesis of thioureas and related derivatives using the novel synthon, (11) CS2 , is reported. This approach has enabled the facile labelling of a potent progesterone receptor (PR) agonist, [(11) C]Tanaproget, by the intramolecular reaction of the acyclic aminohydroxyl precursor with (11) CS2 , which has potential applications as a positron emission tomography radioligand for cancer imaging.