Abstract
Background and purpose: Mammography is one of the most reliable techniques for early detection of nonpalpable breast cancer. Magnification mammography offers better resolution than conventional one in spite of increasing patient dose. The goals of this study were to evaluate the mean glandular dose, exposure time and image quality in magnification mammography. Methods: All measurements were performed on a mammography unit with a molybdenum and rhodium target and a filter combination of molybdenum, rhodium and aluminum. Gross optical densities of phantom images were measured using a densitometer. Image quality was quantified by image detail detection and image contrast. Results: Increasing x-ray tube potential from 26 kVp to 35 kVp reduces the exposure time from 1 s to 0.25 s and mean glandular dose from 1.95 mGy to 1.20 mGy. In evaluation of the image quality, the detection of fibers and masses does not vary with the increasing x-ray tube voltage, but the detection of speeks does. Conclusion: It is concluded that magnification mammography at high kVp significantly reduces exposure time and mean glandular dose, with a similar capability in detecting fibers and masses to that at low kVp. But the detect ability of calcification at 35 kVp may significantly worsened than that performing at 26 kVp. It is our recommendation that the elevation of high kVp (up to 35 kVp) in the study of lesions with fibers and masses might be helpful, but not in the survey of calcified specks.