Menstrual cycle and age: influence on parenchymal contrast medium enhancement in MR imaging of the breast.

PURPOSE To evaluate the influence of menstrual cycle and age on parenchymal contrast medium enhancement in magnetic resonance (MR) imaging of the breast. MATERIALS AND METHODS Dynamic gadolinium-enhanced fast low-angle shot, three-dimensional breast MR imaging was performed with high temporal and spatial resolution (eight measurements in 10 minutes). Menstrual cycle evaluations and age-influence studies were performed in 44 patients aged 27-55 years with a regular cycle (mean age, 41.5 years) and in 103 patients aged 15-79 years (mean age, 49.3 years), respectively. A region of interest was placed in each quadrant of the breast for evaluation of parenchymal enhancement. Quadrants with complete involution or lesions and patients who received hormonal therapy were excluded [corrected]. Analysis of variance was performed. RESULTS Parenchymal contrast medium enhancement in cycle days 7-20 (geometric mean enhancement at minutes 1-10 = 0.12-0.47) was significantly lower than that in cycle days 21-6 (geometric mean, 0.17-0.98; P < or = .001). Contrast medium enhancement in patients aged 35-50 years (mean enhancement, 0.17-0.75) was significantly higher than that in patients aged younger than 35 years or older than 50 years (mean enhancement, 0.12-0.40; P < .01). CONCLUSION Patients showed statistically significantly lower parenchymal enhancement in menstrual cycle days 7-20 than in days 21-6. Patients aged 35-50 years yielded higher parenchymal enhancement than did younger patients and older patients.