Impact of Magnification Views on the Characterization of Microcalcifications in Digital Mammography

Abstract

!Purpose: To evaluate the additional benefit of true geometric (air-gap) magnification views for the characterization of microcalcifications in digital mammography. Materials and Methods: After ethical approval, we retrospectively reviewed patient records to identify 100 patients with suspicious microcalcifications (35 malignant, 65 benign) who had a standard digital mammography and an additional digital magnification view in the same projection within three months. All images were obtained using an amorphous silicon-based full-field digital system (Senographe 2000 D, GE Healthcare, Chalfont St. Giles, UK). Images were independently analyzed by six board-certified radiologists. The probability of malignancy was estimated using first standard contact mammography alone (MG) and then mammography in combination with the magnification view (MG+MAG) using a modified Breast Imaging Reporting and Data System (BI-RADS) classification system and a percentage scale. Results were compared using receiver operating characteristic (ROC) analysis. In addition, readers assessed the subjective visibility of the calcifications. Results: For all six readers combined, the area under the curve (AUC) was 0.664 ± 0.052 for MG and 0.813 ± 0.042 for MG + MAG, resulting in a statistically significant improvement of 0.148 ± 0.120. Each reader had a higher AUC for MG + MAG than MG, with the improvement being statistically significant in four of the six readers. In 76.34 % of the cases, MG + MAG resulted in better visibility of calcifications compared with mammography alone. In 33 % slightly more and in 39 % significantly more calcifications were found. Conclusion: Even in digital mammography with the option of using electronic magnification (zoom) at the viewing workstation, true geometric (air-gap) magnification views remain imporThis document was downloaded for personal use only. Unauthorized distribution is strictly prohibited.

A Micro CT Study in Patients with Breast Microcalcifications Using a Mathematical Algorithm to Assess 3D Structure

“…This estimated PPV is in accordance with other studies reporting a PPV in the order of 30–50% for MC undergoing biopsy [4, 5]; therefore, it may be assumed that a typical mammography screening cohort was evaluated in this prospective analysis.…”

“…Several approaches have been undertaken to improve the assessment of MC including X-ray magnification views [4, 6, 22–29] and computer-aided detection with partially successful results: the contrast-limited adaptive histogram equalization (CLAHE) technique for example showed promising results for the computer-aided detection in digital mammograms with a sensitivity of 92.54% and a specificity of 92.50% [30]. However, assessment of the real 3D structure of MC remains challenging in 2D projection views.…”

“…The evaluation of mammograms is standardized according to the American College of Radiology (ACR) Breast Imaging Reporting and Data System (BIRADS) classification. One of the key findings for the detection of suspicious breast lesions and an important sign of malignancy is microcalcifications (MC) [4, 5]. Typically, the shape of the MC in breast lesions is used to classify the finding as benign or malignant [6–9].…”

Digital zoom of the full-field digital mammogram versus magnification mammography: a systematic review

“…Following the close reading, further 12 articles were excluded and 9 articles were finally selected for inclusion: five experimental phantom studies [36][37][38][39][40] and four retrospective diagnostic test studies [41][42][43][44].…”

“…Diagnostic test studies [41][42][43][44] reported clinical characteristics and diagnostic accuracy data for magnification and zoom at a threshold equal to or equivalent to BIRADS ≥ 4a [48], see Table 3. The ranges of sensitivity and specificity were 85-100% and 50-57%, respectively, for magnification.…”