To compare the parameters in two different compression modes of the same mammography machine and evaluate their application value.

The clinical data of patients who underwent mammography in the Cancer Hospital Tianjin Medical University from January 2018 to November 2019 were retrospectively collected. We enrolled 2 000 patients undergoing mammography in normal compression mode (group A) and 2 000 patients in fully automatic self-adjusting tilt mode (group B). After excluding patients with large tumors, history of surgery and chemotherapy, there were 1 950 patients in group A and 1 781 patients in group B. The compression of breast thickness (CBT), pressure, and average glandular dose (AGD) were compared between two groups by rank sum test. The image quality was compared by χ² test. The pain score of the patients was compared by independent sample t test.

The X-ray images of patients in two groups were all qualified, and there were no waste films. There were 1798 cases of grade A films, 132 grade B films and 20 grade C films in group A, 1639, 109 and 33 in group B, suggesting no significant difference between two groups (χ²=5.095, P=0.078). The CBT in groups A and B was 44(37, 51) mm and 45(37, 52) mm, respectively, suggesting no significant difference (Z=1.913, P=0.056). The pressure in groups A and B was 83(66, 99) N and 83(62, 100) N, respectively, with no significant difference (Z=1.222, P=0.222). AGD in groups A and B was 1.29(1.01, 1.63) mGy and 1.30 (0.98, 1.62) mGy, respectively, with no significant difference (Z=0.539, P=0.590). The pain score was 4.32±2.02 in group A and 4.42±2.14 in group B, respectively, suggesting no significant difference (t=-0.241, P=0.810).

The two compression modes in mammography lead to no obvious difference in image quality and pain of patients, so compression can be individualized depending on the patient’s condition.