|ECR 2019 / C-1620|
|Usefulness of fusion MRI in ADC analysis after neoadjuvant chemotherapy in patients with breast cancer|
Aims and objectives
Diffusion Weighted Imaging (DWI) and DCE-MRI (Dynamic Contrast Enhanced-MRI) are the most useful sequences to study breast cancer on MRI.
DWI acquisition represents the diffusion or motion of water molecules in a voxel due to Brownian motion.
Hyperintense areas in DWI correspond to restricted diffusion of water molecules determined by tissue properties (e.s lipophilic cell membranes in normal tissues), tissues with a high cellular density (e.s. breast cancer) and water molecules in the interstitial compartment (e.s. edema).
Low hyperintense signal is typical of normal breast tissue while higher hyperintense signal is typical of breast cancer and necrotic areas because, in the first case, cells are more densely packed and the extracellular space is reduced, while, in the second case, there are many water molecules in the interstitial compartment, without free motion .
The ADC map quantifies the hyperintense signal on DWI sequence, which corresponds to hypointense ADC areas.
Different ADC values allow to distinguish normal breast tissues from mass cancer and necrotic areas, and also allow to differentiate malignant tumor from the benign ones  by delineating a ROI (Region Of Interest) in the hypointense areas.
However little tumor mass are slightly recognizable in the ADC map because of the poor sensitivity of the DWI acquisition.
Dynamic contrast-enhanced (DCE) MRI depicts tissues vascularization during the injection of intravenous paramagnetic contrast (Gadolinium) and shows blood flow and vessel permeability.
However, after neoadjuvant chemotherapy (NACT) in patients with breast cancer, DCE-MRI, which is a morphological MR imaging, has suboptimal potentiality to distinguish the viable tumor tissue from scar, necrosis, fibrosis and reactive inflammation; so this may leads to wrong interpretation of the response to chemotherapy .
Fusion- MRI is a post-processing technique obtained by overlapping ADC map and DCE-MRI.
Through fusion technique, this study aims to evaluate the positive response to NACT in patients with breast cancer by distinguishing little residual tumoral mass from necrosis, fibrosis or reactive inflammation.
Thematically related posters
ECR 2019 / C-0525
Influence of ROI placement: different ADC metrics on diagnostic accuracy of DWI in NME breast tumours
ECR 2019 / C-1117
Multiparametric MRI with dynamic contrast enhanced MRI and diffusion weighted imaging for the assessment of non-mass enhancing breast tumours