Perspectives in imaging using mass spectrometry

Abstract

Imaging mass spectrometry (MS) allows a remarkable range of measurements including diagnosis of disease state of tissue based on detailed information on its chemical constituents, especially lipids and proteins. The recent emergence of ambient ionization allows imaging in the open environment without sample preparation. In this review, we briefly describe the history of imaging MS highlighting its main techniques and applications. We also demonstrate how the detailed molecular information obtained by imaging MS makes this technique suitable for a range of forensic and clinical applications with the potential to be successfully developed all the way to intra-surgical practice.

Fig. 1

Overview of tissue processing to achieve a diagnosis by traditional pathological staining techniques and by DESI imaging mass spectrometry.

Fig. 2

Simplified mechanistic diagrams for the four most commonly used ionization techniques in imaging mass spectrometry; matrix assisted laser desorption ionization (MALDI), secondary ion mass spectrometry (SIMS), laser ablation electrospray ionization (LAESI) and desorption electrospray ionization (DESI).

Fig. 3

Overview of selected DESI-MS imaging applications, including disease diagnosis, 3D molecular image reconstruction, mapping of drugs in biological tissue and forensics applications.