Imaging tissue

You mean if I take a slice of my brain I could use MS to get an image of its component molecules  

Now I understand why they came up with the Darwin awards. 

Reference P. Chaurand, D. S. Cornett, P. M. Angel, and R. M. Caprioli, From whole-body sections down to cellular level, multiscale imaging of phospholipids by MALDI mass spectrometry. Mol. Cell. Proteomics 10 1-11 (2011). 

Background Since its introduction 15 years ago, imaging of tissues by MALDI has rapidly expanded to include peptides, proteins, multiple classes of lipids, as well as small molecules such as metabolites and xenobiotics. Tissues examined have ranged from frozen tissue sections to formalin-fixed paraffin-embedded sections, and have been obtained from a wide variety of sources, including from whole animals to specific tissues, e.g., kidney and eye lens, as well as normal and diseased states. While TOF (and TOF/TOF) remains the most frequently used technique, other approaches, including MS/MS using QTOF, trap-TOF, ion mobility, and FT-trap formats, have also been reported. This paper describes analysis of tissue sections from the whole body to subsections of tissues, down to the cellular level. 

Methods The MALDI process requires a matrix that is usually dissolved in a solvent prior to its addition to the sample. For tissue samples an even coating of the matrix can be obtained by spraying a solution onto the sample. A potential problem is that the solvent may affect the quality of the tissue image by solubilizing and 

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Magnetic resonance imaging (MRI) Soft-tissue imaging to evaluate for tendon or ligament tears. 

Ultrasound Superficial soft-tissue imaging to evaluate for tears in tendons or ligaments. Does not penetrate bone, so it is of limited usefulness for assessing tendons or ligaments deep within joints. 

J. M. Wiseman, D. R. Ifa, Q. Song and R. G. Cooks, Tissue imaging at atmospheric pressure using Desorption Electrospray Ionization (DESI) mass spectrometry, Angew. Chem. Int. Edn, 45, 7188 7192 (2006). 

A. Brunelle, D. Touboul and O. Laprevote, Biological tissue imaging with time of flight secondary ion mass spectrometry and cluster ion sources, Journal of Mass Spectrometry, 40,985 999 (2005). 

F. Kallel, R. J. Stafford, R. E. Price, R. Righetti, J. Ophir and J. D. Hazle, The feasibility of elastographic visualization of HIFU-induced thermal lesions in soft tissues. Image-guided high-intensity focused ultrasound, Ultrasound Med. Biol., 1999, 25, 641-647. 

Fig. 2. Soft tissue imaging can be accomplished in pre- and postnatal specimens by micro-CT. Top rowdepicts a maximum intensity projection or WIIP view of an El 5 mouse embryo left) and PO mouse pup (right). Bottom rowdepicts a 2D slice view, technically termed a reformat, of the same El 5 (left) and PO (right) from the data set depicted above. The soft tissue features can be seen along with skeletal signal as volumetric or two-dimensional slices of the specimen in all anatomical viewing planes, including oblique angles, if desired.

By taking advantage of the deep penetration depth offered by CARS microscopy with near-infrared laser pulses, CARS tissue imaging has been demonstrated to complement other label-free optical techniques, such as auto-fluorescence that is limited to a few chemical species and optical tomography, second harmonic generation (SHG), and third harmonic generation (THG)... 

Crossman, L. F., Cui, X., Knemeyer, I., Morrison, R., Hsieh, Y., and Korfmacher, W. (2007). Multilevel MALDI MS tissue imaging of pharmaceuticals, In Proceedings of the 55th ASMS Conference on Mass Spectrometry and Allied Topics, Indianapolis, IN. 

Applications of FTIR tissue imaging to cervical cancer... 

Han J, Schey K (2006) MALDI tissue imaging of ocular lens a-crystalline. Invest Ophthalmol... 

Manicke N, Dill A, Ifa D, Cooks R (2010) High-resolution tissue imaging on an orbitrap mass spectrometry by desorption electrospray ionization mass spectrometry. J Mass Spectrom 45 223-226. doi 10.1002/jms,1707... 

Patti G, Woo H, Yanes O, Shriver L, Thomas D, Uritboonthai W, Apon J, Steenwyk R, Manchester M, Siuzdak G (2010) Detection of carbohydrates and steroids by cation-enhanced nanostructure-initiator mass spectrometry (NIMS) for biofluid analysis and tissue imaging. Anal Chem 82 121-128. doi 10.1021/ac9014353... 

Yanes O, Woo H, Northen T, Oppenheimer S, Shriver L, Apon J, Estrada M, Potchoiba M, Steenwyk R, Manchester M, Siuzdak G (2009) Nanostructure initiator mass spectrometry tissue imaging and direct biofluid analysis. Anal Chem 81 2969-2975. doi 10.1021/ ac802576q... 

As far as applications of XDI, the comparison with MRI is illuminating. MRI has from its beginnings found a ready application for soft-tissue imaging in diagnostic radiology, driven by the powerful market forces at work in the health-care sector. 

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