Biologie moléculaire : accès libre

In Vivo Spectroscopy vis-à-vis Ex Vivo Spectroscopy: Pearls and Pitfalls: Imaging Review

Abstract

Khizer Razak, Surbhi Gupta and Meena GL

Aims and objective: The objective of this communication is to bring the metabolomics by magnetic resonance (high resolution spectroscopy) to the clinical radiologist and compare the spectroscopy In vivo (NMR spectroscopy used in clinical) with the high resolution spectroscopy Ex vivo (magic angle spectroscopy, HR –MORE). S and analyzing differences, advantages and limitations of each technique in different tissues.
Review of the topic: In vivo spectroscopy that is usually performed in the clinic is a non-invasive technique that can provide important information for the diagnosis and monitoring of different lesions. The most well-known applications of In vivo spectroscopy today are those carried out by localized 1H spectroscopy, monovoxel or multivoxel (spectroscopic image), brain, prostate or breast. There are other modalities, such as the 31 P or 13ºC spectroscopy, but they are much less frequent and are only carried out in a few specialized centres. Without any doubt, the most widespread clinical use is confined to the central nervous system.
Conclusion: The in vivo spectroscopy provides important metabolic information for the diagnosis of different pathologies, non-invasively, however, this technique has certain limitations, such as low spectral resolution, that is, the number of metabolites that can be identified/quantified; which results in low diagnostic specificity.

Ex vivo spectroscopy, however, has a spectral resolution and sensitivity far superior to In vivo techniques, which allows detecting a large number of metabolites, and therefore greatly improves its diagnostic capacity. However, we must not forget that it is an invasive technique, since it is based on the analysis of pieces of tissue (biopsies, surgical pieces...) and therefore loses its usefulness in those lesions that are impossible to biopsy. In conclusion, each technique has its added value and its limitations and it is the correct use of them and the combination of them with other diagnostic parameters, where their clinical potential resides.