SMART: A data reporting standard for mass spectrometry imaging

Abstract

Mass spectrometry imaging (MSI) is an important analytical technique that simultaneously reports the spatial location and abundance of detected ions in biological, chemical, clinical, and pharmaceutical studies. As MSI grows in popularity, it has become evident that data reporting varies among different research groups and between techniques. The lack of consistency in data reporting inherently creates additional challenges in comparing intra‐ and inter‐laboratory MSI data. In this tutorial, we propose a unified data reporting system, SMART, based on the common features shared between techniques. While there are limitations to any reporting system, SMART was decided upon after significant discussion to more easily understand and benchmark MSI data. SMART is not intended to be comprehensive but rather capture essential baseline information for a given MSI study; this could be within a study (e.g., effect of spot size on the measured ion signals) or between two studies (e.g., different MSI platform technologies applied to the same tissue type). This tutorial does not attempt to address the confidence with which annotations are made nor does it deny the importance of other parameters that are not included in the current SMART format. Ultimately, the goal of this tutorial is to discuss the necessity of establishing a uniform reporting system to communicate MSI data in publications and presentations in a simple format to readily interpret the parameters and baseline outcomes of the data.

A Guide to MALDI Imaging Mass Spectrometry for Tissues

“…Xi et al proposed a standard for unified data reporting. this system, SMART, is designed to quickly communicate the experimental parameters that define an image within the image margin or caption. SMART metrics are defined as follows: [S] step size, spot size, and scans (total pixels,) [M] molecular identification confidence, [A] Annotations, [R] resolution, and [T] time of acquisition.…”

“…134 Molecular identification confidence is also discussed in the SMART guidelines, a data reporting standard for imaging data. 134,135 Analyte identification is not the same as target validation; there is always a need for ancillary confirmation of the identification. This means that although the data suggests an identification, confirmation of the target is necessary to draw biological conclusions.…”

“…Schymanski et al explore the concept of confidence in analyte identification with a proposed level system to communicate the confidence of an identification and the minimum data required to support the claim . Molecular identification confidence is also discussed in the SMART guidelines, a data reporting standard for imaging data. , …”

A label-free approach for relative spatial quantitation of c-di-GMP in microbial biofilms

“…Other details regarding the acquisition parameters are indicated in each figure using the 'SMART' standardized nomenclature. 49 Step size, spot size, and scan number (S), molecular identification (M), annotations (A), mass resolution (R), time of acquisition (T) are provided. All molecular identifications (M) were done to the MS1 level or using a commercial standard, all annotations (A) were targeted and no database searching was used and the mass resolution (R) in all experiments was 65,000 FWHM at m/z 1222.…”

Evaluating the optimal tissue thickness for mass spectrometry imaging using infrared matrix‐assisted laser desorption electrospray ionization

“…I G U R E 5 Heat map of cholesterol (m/z 369.3516) in mouse liver for each tissue thickness studied. The SMART data reporting standard is used to display relevant MSI (mass spectrometry imaging) information (increasing tissue thickness order) 34. [Color figure can be viewed at wileyonlinelibrary.com] F I G U R E 6 Averaged mass spectra for each sample indicating change in abundance across the sample thicknesses.…”