To investigate whether background parenchymal enhancement (BPE) may influence the sensitivity of dynamic contrast-enhanced magnetic resonance (DCE-MR) imaging in breast cancer detection.

A total of 180 consecutive women with 194 breast cancers underwent MR imaging examination. Women were assigned to two different groups depending on the degree of BPE. Group 1 consisted of women with minimal or mild BPE and group 2 of women with moderate or marked BPE. The distributions of histotypes of tumors within the two groups were compared using the χ² test. Difference in sensitivities of DCE-MR imaging for tumor detection between the two groups was searched for using the Student t-test.

No differences in terms of distributions of histotypes of tumors between the two groups of women were found (P=0.5). The 11% difference in sensitivity of DCE-MR imaging for tumor detection between group 1 (91/92; 99%; 95% CI: 94–100%) and group 2 (90/102; 88%; 95% CI: 80–94%) was statistically significant (P=0.0058).

The sensitivity of DCE-MR imaging is significantly lower in women with moderate and marked BPE as compared with women with minimal and mild BPE regardless of cancer histotype. BPE could represent a limitation for breast MR imaging interpretation and should be indicated in MR imaging reports.