Quantitative evaluation of background parenchymal enhancement (BPE) on breast MRI. A feasibility study with a semi-automatic and automatic software compared to observer-based scores

Objective: To evaluate quantitative measurements of background parenchymal enhancement (BPE) on breast MRI and compare them with observer-based scores. Methods: BPE of 48 patients (mean age: 48 years; age range: 36-66 years) referred to 3.0-T breast MRI between 2012 and 2014 was evaluated independently and blindly to each other by two radiologists. BPE was estimated qualitatively with the standard Breast Imaging Reporting and Data System (BI-RADS) scale and quantitatively with a semi-automatic and an automatic software interface. To assess intrareader agreement, MRIs were re-read after a 4-month interval by the same two readers. The Pearson correlation coefficient (r) and the Bland-Altman method were used to compare the methods used to estimate BPE. p-value 0.05). Mean values of BPE percentages for the automatic software were 17.5613.1 (p>0.05 vs semi-automatic). The automatic software was unable to produce BPE values for 2 of 48 (4%) patients. With BI-RADS, interreader and intrareader values were k50.70 [95% confidence interval (CI) 0.49-0.91] and k50.69 (95% CI 0.46-0.93), respectively. With semi-automated software, interreader and intrareader values were k50.81 (95% CI 0.59-0.99) and k50.85 (95% CI 0.43-0.99), respectively. BI-RADS scores correlated with the automatic (r50.55, p