Breast compression and reported pain during mammographic screening.

INTRODUCTION: We aimed to investigate the association between breast compression and experienced pain during mammographic screening. METHODS: Using a questionnaire, we collected information on pain experienced during mammography from 1155 women screened in Akershus, February-March 2018, as a part of BreastScreen Norway. The questionnaire provided information on pain using a numeric rating scale (NRS, 0-10) and related factors. Data on compression force (Newton, N), pressure (kilopascal, kPa) and breast characteristics were extracted from the DICOM-header and a breast density software. Log-binomial regression was used to determine the relative risk (RR) of severe versus mild/moderate experienced pain associated with compression parameters, adjusting for breast characteristics and related factors. RESULTS: Mean score of experienced pain was 2.2, whereas 6% of the women reported severe pain (≥7) during the examination. High body mass index (BMI) (≥27.3 kg/m2) was associated with a higher RR of pain scores ≥7 (RR 1.86, 95%CI 1.02-3.36) compared to medium BMI (23.7-27.2 kg/m2). Low compression pressure (4.0-10.2 kPa) was associated with a higher RR of severe pain (RR 2.93, 95%CI 1.39-6.20), compared with medium compression pressure (10.3-13.5 kPa) after adjusting for contact area, age, compressed breast thickness, volumetric breast density and BMI. The risk of severe versus mild/moderate pain (≥7 versus <7) decreased by 2% with increasing compression force (RR 0.98, 95%CI 0.97-1.00). CONCLUSION: Women reported low levels of pain during mammography. Further knowledge about factors affecting experienced pain is needed to personalize the examination to the individual woman. IMPLICATIONS FOR PRACTICE: Pain in shoulder(s) and/or neck prior to screening should be considered by the radiographers in a practical screening setting. A compression force of 100-140 N and pressure of 10.3-13.5 kPa are acceptable with respect to reported pain during mammography.

Development of a phantom to test fully automated breast density software - A work in progress.

OBJECTIVES: Mammographic density (MD) is an independent risk factor for breast cancer and may have a future role for stratified screening. Automated software can estimate MD but the relationship between breast thickness reduction and MD is not fully understood. Our aim is to develop a deformable breast phantom to assess automated density software and the impact of breast thickness reduction on MD. METHODS: Several different configurations of poly vinyl alcohol (PVAL) phantoms were created. Three methods were used to estimate their density. Raw image data of mammographic images were processed using Volpara to estimate volumetric breast density (VBD%); Hounsfield units (HU) were measured on CT images; and physical density (g/cm3) was calculated using a formula involving mass and volume. Phantom volume versus contact area and phantom volume versus phantom thickness was compared to values of real breasts. RESULTS: Volpara recognized all deformable phantoms as female breasts. However, reducing the phantom thickness caused a change in phantom density and the phantoms were not able to tolerate same level of compression and thickness reduction experienced by female breasts during mammography. CONCLUSION: Our results are promising as all phantoms resulted in valid data for automated breast density measurement. Further work should be conducted on PVAL and other materials to produce deformable phantoms that mimic female breast structure and density with the ability of being compressed to the same level as female breasts. ADVANCES IN KNOWLEDGE: We are the first group to have produced deformable phantoms that are recognized as breasts by Volpara software.