ElastoMRI Evaluation of Hepatic Metastases in Colorectal Cancer ( MetaIRM)

Currently, the tumor response of operated colorectal liver metastases is assessed by histology of the resection specimen.The histological data make it possible to define categories (responder, partial responder, non-responder).

Overall survival (OS: overall survival) after surgery crucially depends on the response to neoadjuvant chemotherapy. Current criteria for predicting histological response in preoperative imaging are not satisfactory.

The working hypothesis is that it is possible to better differentiate the tissue response to conventional chemotherapies and anti-angiogenics through MRI elastography by quantifying the changes in tissue mechanical properties induced by systemic treatments.

The objectives is to evaluate the mechanical properties obtained by elasto MRI according to the systemic treatments envisaged: conventional chemotherapy such as Folfox or combined with targeted therapy

Currently, the tumor response of operated colorectal liver metastases is assessed by histology of the resection specimen.The histological data make it possible to define categories (responder, partial responder, non-responder).

Overall survival (OS: overall survival) after surgery crucially depends on the response to neoadjuvant chemotherapy. Current criteria for predicting histological response in preoperative imaging are not satisfactory.

The working hypothesis is that it is possible to better differentiate the tissue response to conventional chemotherapies and anti-angiogenics through MRI elastography by quantifying the changes in tissue mechanical properties induced by systemic treatments.

The objectives is to evaluate the mechanical properties obtained by elasto MRI according to the systemic treatments envisaged: conventional chemotherapy such as Folfox or combined with targeted therapy

This is an open, non-randomized, non-comparative trial with three parallel groups

* 10 patients immediately resectable and receiving preoperative chemotherapy based on Folfox alone.
* 30 potentially resectable patients (borderline) with two groups of patients representing the combinations usual triplets: chemotherapy and targeted therapy: Folfox+bevacizumab (15 patients) and Folfox + Cetuximab (15 patients).
* 10 unresectable patients with two groups of patients representing the usual combinations: cytotoxic pure vs cytotoxic + targeted therapy (bevacizumab or Cetuximab).

Eligibility Criteria:
Inclusion Criteria:

* Adult patients ≥18 years old, followed for colorectal cancer with hepatic metastases.

The diagnosis of metastasis can be made: either by tumor biopsy or by the appearance during follow-up of colorectal cancer of at least one liver lesion with the characteristics of metastasis (fibrous tumor type imaging)

* Patient with an indication to receive first-line chemotherapy for liver metastases, whether or not associated with targeted therapy
* Patient with at least one hepatic metastasis greater than 2cm

Exclusion Criteria:

* Patients not affiliated with social security
* Pregnant or breastfeeding women
* Patients under guardianship, curatorship or safeguard of justice
* Patients with a contraindication to MRI or to the injection of contrast agent in MRI. The classic contraindications for MRI are defined by the French Society of Radiology:http://www.sfrnet.org/sfr/professionnels/1-fiche-information-patients/irm/index.phtml
* Lack of signed patient consent