Software solutions for evaluation and visualization of laser ablation inductively coupled plasma mass spectrometry imaging (LA-ICP-MSI) data: a short overview

Abstract

Mass spectrometry imaging (MSI) using laser ablation (LA) inductively coupled plasma (ICP) is an innovative and exciting methodology to perform highly sensitive elemental analyses. LA-ICP-MSI of metals, trace elements or isotopes in tissues has been applied to a range of biological samples. Several LA-ICP-MSI studies have shown that metals have a highly compartmentalized distribution in some organs, which might be altered in consequence of genetic diseases, intoxication, or malnutrition. Although metal imaging by LA-ICP-MSI is an established methodology, potential pitfalls in the determination of metal concentrations might result from erroneous calibration, standardization, and normalization. In addition, for simple display of final imaging results, most LA-ICP-MSI users prefer to process their measurements by commercial processing software. Such programs typically visualize the regional metal differences in colorful and vivid imaging maps, but might not represent the actual signal densities correctly. There is a great abundance of such MSI data processing programs available differing in quality, usability, integrated features, workflow, reliability, system requirements, speed of data processing, and price. Some software packages contain a multitude of features which are superfluous for most users. In contrast, often only few data formats are used, in case of commercial programs even only the instrument provider’s own raw data format. Therefore, first time and average users are often confused and helpless in choosing the correct software for processing their data. Here we have briefly summarized software packages, data routines, macros, programming tools, scripts, algorithms, or self-written patches and updates for existing programs presently in use for mining LA-ICP-MSI data.

Laser Ablation Inductively Coupled Plasma Spectrometry: Metal Imaging in Experimental and Clinical Wilson Disease

“…In most cases, LA-ICP-MSI generates raw data files requiring extensive editing and formatting before data can be used to generate high-quality elemental distribution maps. For this purpose, a large abundance of commercial, open-source, or in-house programs and software routines have been introduced [30]. The plethora of software available used for LA-ICP-MSI data mining is multifarious allowing depicting results in many formats.…”

“…The plethora of software available used for LA-ICP-MSI data mining is multifarious allowing depicting results in many formats. However, this large abundance might prevent the exchange of data between different laboratories [30].…”

“…All LA-ICP-MSI data were visualized with the modularly constructed in-house software tool Excel Laser Ablation Imaging (ELAI) allowing for the reconstruction of element distribution maps using Microsoft Excel with the aid of Visual Basic for Applications (VBA) [30]. Details about this software tool were published previously [72].…”

Capabilities of automated LA-ICP-TOFMS imaging of geological samples

“…As noted earlier by Paul et al, 40 soware development for LA-ICP-MS imaging is lagging behind compared to other imaging techniques. A detailed discussion of this issue can be found in a review by Weiskirchen et al 41 Until now, the major focus was on soware solutions for data analysis. [40][41][42][43][44][45][46] Nevertheless, the more LA-ICP-TOFMS imaging becomes routine, the more need there is for an automation of the data acquisition process.…”

Open LabBot and RmsiGUI: Community Development Kit for Sampling Automation and Ambient Imaging

“…The imzML data format [21] has developed to the community standard in mass spectrometry imaging (MSI). For maintaining compatibility with other programs [22], we implemented the imzML format in our data processing software.…”