Quantitative Breast Background Parenchymal Enhancement: Improved Effect Size when Expressed as Contrast Agent Concentration

Motivation: Background parenchymal enhancement (BPE) is linked to cancer treatment outcomes. Unfortunately field strength, acquisition parameters, etc, influence BPE. More reliable methodology is needed. Goal(s): We tested a novel BPE measure as contrast concentration to differentiate patient groups. Test1: pathologically complete response after neo-adjuvant therapy vs incomplete response. Test 2: pre- vs post-menopause. Approach: From a large public imaging archive we randomly selected 32 exams each for Tests 1-2 to compare effect sizes for signal and concentration-based BPE. Results: For both tests, group effects measured using Cohen-d were 2X larger for concentration-based BPE. BPE robustness is improved by converting MR signal to contrast concentrationImpact: Background parenchymal enhancement (BPE) is linked to cancer treatment outcomes. Unfortunately field strength, acquisition parameters, etc, influence conventionally acquired BPE. We propose and validate, using two independent datasets, a more reliable BPE methodology based on quantitative measurement of contrast concentration.