Objectives: The purpose of the present study was to evaluate BPE in the contralateral breast of biopsy-proven breast cancer patients
and comparison of the results with the control group. Patients and Methods: In a case-control study, CE-MRI of the contralateral
breasts of 40 biopsy-proven breast cancer patients and 40 patients with biopsy-proven benign breast lesions were retrospectively
reviewed by an experienced radiologist and degree of BPE, and pattern of enhancement of the lesions in the involved breast were
determined. Finally, BPE was compared between case and control groups using Chi-square test. P-value <0.05 was considered
significant. Results: In the case group, 4 (10%), 17 (42.5%), 14 (35%) and 5 (12.5%) patients had minimal, mild, moderate and marked
BPE in the normal contralateral breast, respectively. In the control group, 12 (30%), 24 (60%) and 4 (10%) participants had minimal,
mild and moderate BPE in the normal contralateral breast, respectively. BPE in the normal contralateral breast was significantly
higher in the case group in comparison with the control group (P-value: 0.001). In the case group 4 (10%), 26 (65%) and 10 (25%)
patients had mass-non-mass, mass, and non-mass patterns, respectively. In the control group, 24 (60%) and 16 (40%) participants
had mass and non-mass pattern, respectively. The pattern of enhancement in the involved breast was significantly different between
the two groups (P value: 0.002). No statistically significant difference was found in degree of BPE according to enhancement pattern
subtype of breast lesions in both groups (P value>0.05). Conclusion: Our study revealed that patients with the diagnosis of breast
cancer have greater degree of BPE in the normal contralateral breast, in comparison with the control group.
Keywords: : Background enhancement, High-risk breast cancer, Magnetic Resonance Imaging