Validation of this new device demonstrates the potential to increase the distribution of cost-effective scoliosis screening tools to a broad population of medical providers.

Therapeutic level IV. See Instructions for Authors for a complete description of levels of evidence.

Mass cytometry is an emerging technology capable of 40 or more correlated measurements on a single cell. The complexity and volume of data generated by this platform have accelerated the creation of novel methods for high-dimensional data analysis and visualization. A key step in any high-level data analysis is the removal of unwanted events, a process often referred to as data cleanup. Data cleanup as applied to mass cytometry typically focuses on elimination of dead cells, debris, normalization beads, true aggregates, and coincident ion clouds from raw data. We describe a probability state modeling (PSM) method that automatically identifies and removes these elements, resulting in FCS files that contain mostly live and intact events. This approach not only leverages QC measurements such as DNA, live/dead, and event length but also four additional pulse-processing parameters that are available on Fluidigm Helios™ and CyTOF ® (Fluidigm, Markham, Canada) 2 instruments with software versions of 6.3 or higher. These extra Gaussian-derived parameters are valuable for detecting well-formed pulses and eliminating coincident positive ion clouds. The automated nature of this new routine avoids the subjectivity of other gating methods and results in unbiased elimination of unwanted events. CYTOF instruments were invented as an alternative technology to flow cytometry (1,2). Instead of fluorescent molecules, heavy metals are conjugated to antibodies, which bind to specific epitopes on cells (3). Metal-labeled cells are detected and quantified by inductively coupled plasma mass spectrometry (ICP-MS) with time-of-flight detection (4). Because this technology avoids spectral overlap of fluorescent dyes and isotopic metal contamination is well less than 5%, the number of correlated measurements is mainly limited by the number of stable isotopes of rare earth metals, which realistically could soon reach 100 or more (5).Whether a cytometer is fluorescence-based or metal-based, there are always undesired events that need to be eliminated prior to analysis. Typical flow cytometers have internal circuitry or logic that ignores signal-derived pulses that are partially formed or abnormally long. Flow cytometry often employs a forward by 90 light-scatter gate to eliminate debris and aggregates. Also, pulse processing features such as peak height, width, and area can be leveraged to reduce the number of aggregates.Since mass cytometry atomizes particles into clouds of positively charged ions, its pulse processing capabilities are mainly targeted at detecting and eliminating coincident ion clouds or poorly formed pulses. Mass cytometry also has DNA intercalators (1) that can eliminate debris and some true aggregates. Both technologies 1 Verity Software House, Topsham, Maine

High‐dimensional mass cytometry data potentially enable a comprehensive characterization of immune cells. In order to positively affect clinical trials and translational clinical research, this advanced technology needs to demonstrate a high reproducibility of results across multiple sites for both peripheral blood mononuclear cells (PBMC) and whole blood preparations. A dry 30‐marker broad immunophenotyping panel and customized automated analysis software were recently engineered and are commercially available as the Fluidigm® Maxpar® Direct™ Immune Profiling Assay™. In this study, seven sites received whole blood and six sites received PBMC samples from single donors over a 2‐week interval. Each site labeled replicate samples and acquired data on Helios™ instruments using an assay‐specific acquisition template. All acquired sample files were then automatically analyzed by Maxpar Pathsetter™ software. A cleanup step eliminated debris, dead cells, aggregates, and normalization beads. The second step automatically enumerated 37 immune cell populations and performed label intensity assessments on all 30 markers. The inter‐site reproducibility of the 37 quantified cell populations had consistent population frequencies, with an average %CV of 14.4% for whole blood and 17.7% for PBMC. The dry reagent coupled with automated data analysis is not only convenient but also provides a high degree of reproducibility within and among multiple test sites resulting in a comprehensive yet practical solution for deep immune phenotyping.

In our series of operatively treated navicular stress fractures, 80% went on to union, as verified by CT scan. Patients with united fractures had a clinically significant improvement in outcome, with higher AOFAS and SF-36 scores as compared with the 2 patients with nonunions. Patients with complete, displaced navicular stress fractures may be more likely to develop nonunions.