Ion-to-Image, i2i, a Mass Spectrometry Imaging Data Analysis Platform for Continuous Ionization Techniques

Mass spectrometryimaging (MSI) techniques generate data that revealspatial distributions of molecules on a surface with high sensitivityand selectivity. However, processing large volumes of mass spectrometrydata into useful ion images is not trivial. Furthermore, data fromMSI techniques using continuous ionization sources where data areacquired in line scans require different data handling strategiescompared to data collected from pulsed ionization sources where dataare acquired in grids. In addition, for continuous ionization sources,the pixel dimensions are influenced by the mass spectrometer dutycycle, which, in turn, can be controlled by the automatic gain control(AGC) for each spectrum (pixel). Currently, there is a lack of data-handlingsoftware for MSI data generated with continuous ionization sourcesand AGC. Here, we present ion-to-image (i2i), which is a MATLAB-basedapplication for MSI data acquired with continuous ionization sources,AGC, high resolution, and one or several scan filters. The sourcecode and a compiled installer are available at https://github.com/LanekoffLab/i2i. The application includes both quantitative, targeted, and nontargeteddata processing strategies and enables complex data sets to be processedin minutes. The i2i application has high flexibility for generating,processing, and exporting MSI data both from simple full scans andmore complex scan functions interlacing MSn and SIM scandata sets, and we anticipate that it will become a valuable additionto the existing MSI software toolbox.