Imaging

Image processing

Image processing software for pixel-wise or ROI analysis using ImageJ, a public domain, multi-platform imaging application written in Java. Numerous ImageJ plugins have been developed in-house for parameter estimation and visualization.

Access to additional imaging equipment through collaborative programs

• University of Tübingen, Germany (µPET Focus 120, CTI-Siemens)
• Mixed unit Joseph Fourier University/INSERM U594 Grenoble, France (2.35T, 3T and 7T MRI)
• Laboratory of Biophysics, Faculty of Medicine, Dijon, France (1.5T and 3T MRI)
• Georges-François Leclerc Center, Dijon, France (SPECT)
• Oncodesign is also actively involved in the creation of a regional center of expertise for imaging applied to pharmaceutical, preclinical and clinical research, called PHARMIMAGE. This project, initiated by Oncodesign, federates several academic research teams and the Dijon university hospital in order to create a state-of-the-art imaging platform including PET, SPECT, MRI, ultrasound and CT.

The imaging laboratory routinely performs in vivo and in vitro experiments.

The following summarizes our experience.

Anatomical and morphological imaging (MRI)

• Tumor localization and tumor volume measurements, tumor growth monitoring (before and after treatment), evaluation of tumor heterogeneity (necrosis, viable regions).
• Conventional clinical imaging modalities: cardiac imaging, angiography…

Imaging of tumor biology and physiology (MRI, PET)

• Perfusion and angiogenesis: by the use of endogenous (Arterial Spin Labeling) or exogenous contrast agents (Gd-DTPA, SINEREM), tumor perfusion can be dynamically studied. Parameters such as vascular permeability, vessel size index, vascular volume, blood flow and extravascular-extracellular volume are estimated.
• Contrast agents are chosen depending on their magnetic properties and molecular weight.
• Tumor oxygenation: deoxyhemeoglobin is used as an endogenous contrast agent (BOLD effect) to measure blood flow and tissue oxygenation.
• Diffusion: the diffusion of water molecules in tumor tissues is dominated by flow and diffusion barriers, such as cell membranes. Diffusion-weighted MRI is used to discriminate necrotic from non-necrotic tissues, and evaluate vessel tortuosity.
• [¹⁸F]-FDG PET imaging

MR spectroscopy

MR spectroscopy provides biochemical information from a well-defined region of interest, using the resonant properties of ¹H, ³¹P, ¹⁹F, for example. The types of biological molecules or processes accessible with MRS are:

• ¹H: N-acetyl aspartate, citrate, total choline, total creatine, lactate, lipids, glutamate, glutamine…
• ³¹P: energy status (phosphocreatine, inorganic phosphate, nucleotide phosphate), phospholipid metabolites, intracellular pH…
• ¹⁹F: tumor oxygenation (perfluorocarbon injection), pharmacokinetics studies.

Molecular imaging

Evaluation of “smart” contrast agents: imaging of the STAT3 gene expression by MRI (somatostatin analog linked to Gd-DTPA) and PET (viral thymidine kinase linked with [¹⁸F]-IAU). Gene expression and regulation is followed with reporter gene systems.

Other imaging experiments

• Functional histology after FITC, Hoechst or collagen injection
• Immunoscintigraphy