Estimation of breast volume and its variation during the menstrual cycle using MRI and stereology.

Unbiased estimates of breast volume may be obtained in vivo from systematic series of MR images acquired in accordance with the Cavalieri method of modern design-based stereology. The method does not require any assumptions to be made regarding breast shape. If point counting techniques are used to obtain the required breast section areas estimates, 10-15 min analysis (i.e. counting about 250 points on 12 to 16 images) ensures that the contribution of sectioning and point counting to the coefficient of error (CE) on the volume estimate is less than 3%. The methods were applied to measure breast volume in 15 healthy females aged between 22 and 44 years (mean 31.7 years; SD 8.2 years). One subject was studied on every fourth day during two consecutive cycles. The other 14 subjects were studied on three occasions corresponding to menses, ovulation and pre-menses during a single menstrual cycle. Repeat imaging after repositioning on three occasions within a period of 30 min and also at three different times o...