Eur Radiol (2011) 21: 11–17 DOI 10.1007/s00330-010-1890-8 BREAST Hidetake Yabuuchi Yoshio Matsuo Shunya Sunami Takeshi Kamitani Satoshi Kawanami Taro Setoguchi Shuji Sakai Masamitsu Hatakenaka Makoto Kubo Eriko Tokunaga Hidetaka Yamamoto Hiroshi Honda Received: 13 March 2010 Revised: 10 June 2010 Accepted: 21 June 2010 Published online: 18 July 2010 # European Society of Radiology 2010 Detection of non-palpable breast cancer in asymptomatic women by using unenhanced diffusion-weighted and T2-weighted MR imaging: comparison with mammography and dynamic contrast-enhanced MR imaging Abstract Objective To compare the detectability of non-palpable breast cancer in asymptomatic women by using mammography (MMG), dynamic contrast-enhanced MR imaging (DCE-MRI) and unenhanced MR imaging with combined diffusion-weighted and T2-weighted images (DWI+T2WI). Methods Forty-two lesions in 42 patients with non-palpable breast cancer in asymp- tomatic women were enrolled. For the reading test, we prepared a control including 13 normal and 8 benign cases. Each imaging set included biplane MMG, DCE-MRI and DWI+T2WI. Five readers were asked to rate the images on a scale of 0 to 100 for the likelihood of the presence of cancer and the BI-RADS category. Confidence level results were used to construct receiver operating characteristic analysis. Sensitivity and specificity were calculated for each technique. Results DWI+T2WI showed higher observer performances (area under the curve, AUC, 0.73) and sensitivity (50%) for the detection of non-palpable breast cancer than MMG alone (AUC 0.64; sensitivity 40%) but lower than those of DCE-MRI (AUC 0.93; sensitivity 86%). A combination of MMG and DWI+T2WI exhibited higher sensitivity (69%) compared with that of MMG alone (40%). Conclusion DWI+T2WI could be useful in screening breast cancer for patients who cannot receive contrast medium and could be used as a new screening technique for breast cancer. Keyword Breast . Magnetic resonance imaging . Diffusion- weighted MR image . Non-palpable cancer . Screening Introduction In the screening of breast cancer, mammography (MMG) has been an established technique for many decades, and most women older than 40 years in many countries participate in screening activities [1]. More- over, dynamic contrast-enhanced MR imaging (DCE- MRI) in the high-risk group of breast cancer has been reported to improve detectability of cancer in recent studies [2–8]. In a cohort surveillance of women at high familial risk of breast cancer using various imaging techniques, the sensitivity was low for MMG (33%) and ultrasound (40%) or a combination of both (49%) compared with H. Yabuuchi ()) : Y. Matsuo : S. Sunami : T. Kamitani : S. Kawanami : T. Setoguchi : M. Hatakenaka : H. Honda Department of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan e-mail: yabuuchi@shs.kyushu-u.ac.jp Tel.: +81-92-6426727 Fax: +81-92-6426727 S. Sakai Department of Health Sciences, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan M. Kubo Department of Clinical Oncology and Surgery, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan E. Tokunaga Department of Surgery and Science, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan H. Yamamoto Department of Anatomic Pathology, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan