Breast cancer measurements with magnetic resonance imaging, ultrasonography, and mammography

Background: Accurate measurement of the size of breast cancers becomes more important as breast cancer therapy advances. This study reports the accuracy of magnetic resonance imaging (MRI), ultrasonography and mammography for measuring the largest breast cancer diameter in comparison to the pathology measurement. Materials and methods: Fourteen breast cancers were examined in 13 women with MRI, ultrasonography and mammography. The age range was 31-73 (mean 56). Six of the cancers were in premenopausal women. The MRI was performed with the intravenous injection of gadolinium based contrast agent and a three dimensional fast spoiled gradient echo sequence with fat suppression. The largest cancer diameter was measured with each imaging technique and compared to the largest cancer diameter measured at pathology. Results: At pathological examination cancers ranged from 0.6 to 6 cm (mean 2.2) in largest diameter. MRI measurements had the highest correlation coefficient (r = 0.98) and the smallest standard error (0.34). Ultrasonography measurements had a correlation coeffient of r = 0.45 and a standard error of 0.78. Mammography measurements had a correlation coefficient of r = 0.46 and a standard error of 1.04. Conclusions: MRI was more accurate than ultrasonography and mammography in measuring the largest cancer diameters in this group of women. This was particularly evident for several larger cancers, and a post-chemotherapy cancer.