Tomoyuki Ohta1, Norio Nakata2, Makiko Nishioka3, Takao Igarashi4, Kunihiko Fukuda5. 1. Department of Radiology, The Jikei University, School of Medicine, 3-25-8, Nishi-Shimbashi, Minato-ku, Tokyo, 105-8461, Japan. ohta.kent@nifty.com. 2. Department of Radiology, The Jikei University, School of Medicine, 3-25-8, Nishi-Shimbashi, Minato-ku, Tokyo, 105-8461, Japan. nakata@jikei.ac.jp. 3. Department of Radiology, The Jikei University, School of Medicine, 3-25-8, Nishi-Shimbashi, Minato-ku, Tokyo, 105-8461, Japan. n-makiko@jikei.ac.jp. 4. Department of Radiology, The Jikei University, School of Medicine, 3-25-8, Nishi-Shimbashi, Minato-ku, Tokyo, 105-8461, Japan. igarashi-t@jikei.ac.jp. 5. Department of Radiology, The Jikei University, School of Medicine, 3-25-8, Nishi-Shimbashi, Minato-ku, Tokyo, 105-8461, Japan. fukuda@jikei.ac.jp.
Abstract
PURPOSE: To investigate the usefulness of density gradient of mammographic masses for differentiating benign from malignant lesions, particularly circumscribed masses, which are difficult to diagnose by shape. MATERIALS AND METHODS: Phantom experiments were performed and diagnostic mammography examinations were reviewed. Mammograms of three acrylic resin globes differing in hardness were acquired with/without applied pressure, and density gradients were examined on intensity histograms with standard deviation (SD) as a hardness index. Similar analyses were performed using clinical mammographic examinations of circumscribed mass lesions. The usefulness of SD for differentiating between benign and malignant lesions was investigated by ROC curve analysis and minimum/maximum values of malignant and benign lesions, respectively. RESULTS: For circumscribed masses (n = 196, benign, n = 176; malignant, n = 20), ROC analysis showed AUC = 0.786, with sensitivity = 70.0 %, specificity = 70.5 %, accuracy = 70.4 %, positive predictive value = 21.1 %, and negative predictive value = 95.4 % at SD = 64.46. Minimum and maximum SD of malignant and benign masses were 39.1 and 241.7, respectively. CONCLUSION: On mammography, circumscribed masses can be diagnosed with moderate accuracy using the intensity histogram SD. Masses with SD below the minimum of breast cancer can be roughly diagnosed as clinically benign.
PURPOSE: To investigate the usefulness of density gradient of mammographic masses for differentiating benign from malignant lesions, particularly circumscribed masses, which are difficult to diagnose by shape. MATERIALS AND METHODS: Phantom experiments were performed and diagnostic mammography examinations were reviewed. Mammograms of three acrylic resin globes differing in hardness were acquired with/without applied pressure, and density gradients were examined on intensity histograms with standard deviation (SD) as a hardness index. Similar analyses were performed using clinical mammographic examinations of circumscribed mass lesions. The usefulness of SD for differentiating between benign and malignant lesions was investigated by ROC curve analysis and minimum/maximum values of malignant and benign lesions, respectively. RESULTS: For circumscribed masses (n = 196, benign, n = 176; malignant, n = 20), ROC analysis showed AUC = 0.786, with sensitivity = 70.0 %, specificity = 70.5 %, accuracy = 70.4 %, positive predictive value = 21.1 %, and negative predictive value = 95.4 % at SD = 64.46. Minimum and maximum SD of malignant and benign masses were 39.1 and 241.7, respectively. CONCLUSION: On mammography, circumscribed masses can be diagnosed with moderate accuracy using the intensity histogram SD. Masses with SD below the minimum of breast cancer can be roughly diagnosed as clinically benign.