Examination of Quality Control Guidelines for Digital Breast Tomosynthesis Systems in Japan

The use of mammography equipment attached to a digital breast tomosynthesis (DBT) system is widespread in Japan. Tomosynthesis exposes the breast to X-rays continuously (or in pulses) at different angles in a single scan, yielding multiple projection images. Arbitrary multi-slice images can be reconstructed from the projection images after scanning. However, DBT increases the exposure dose compared to mammography. Therefore, it is necessary to rapidly establish performance evaluation procedures and quality control procedures for DBT. In this study, we conduct quality control measurements on DBT systems sold in Japan by five different companies and examine feasible common items. The purpose of the study was to establish a quality control method for DBT systems in Japan. The measurements were performed based on the EUREF breast tomosynthesis quality control protocol version 1.03. In this study, we attempted to measure 18 items in DBT systems. We examined whether the 18 items could be measured using each system; however, this was not an evaluation of equipment performance based on the measured values. There were some quality control items that were difficult to complete due to the specifications of a DBT system, such as equipment that required pressure during DBT operation, problems due to the shape of the bucky, and equipment that did not have stationary mode. There were also problems related to the availability of measurement data, such as with equipment that could not retrieve projection data and reconstructed data. This study clarified points to be considered for establishing common quality control items. In the future, we will carefully refer to the recently published IEC 61223-3-6, consider international harmonization, and establish DBT guidelines customized for the Japanese market.