Breast cancer is the most common form of cancer among women worldwide. Early detection of breast cancer can increase treatment options and patients' survivability. Mammography is the gold standard for breast imaging and cancer detection. However, due to some limitations of this modality such as low sensitivity especially in dense breasts, other modalities like ultrasound and magnetic resonance imaging are often suggested to achieve additional information. Recently, computer-aided detection or diagnosis (CAD) systems have been developed to help radiologists in order to increase diagnosis accuracy. Generally, a CAD system consists of four stages: (a) preprocessing, (b) segmentation of regions of interest, (c) feature extraction and selection, and finally (d) classification. This paper presents the approaches which are applied to develop CAD systems on mammography and ultrasound images. The performance evaluation metrics of CAD systems are also reviewed.
Matched MeSH terms: Breast Neoplasms/ultrasonography*
The aim of the study was: to obtain the profile of patients (with regards to age and family history of breast cancer) with a palpable breast mass. To determine the validity of ultrasound in the assessment of the palpable breast mass by determining the sensitivity, specificity, positive predictive value, negative predictive value and accuracy of ultrasound in distinguishing a malignant mass. To determine the most discriminating ultrasound characteristics for differentiating benign and malignant masses. Seventy patients who had fine needle aspiration cytology of a palpable breast mass were subjected to an ultrasound assessment of the mass. The ultrasound findings were classified as benign, indeterminate or malignant. These findings were then compared with either the cytology or histology results in cases that eventually had surgical excision. The age of the patients ranged from 15 to 66 years old The majority was in the third and fourth decades with an average age of 25 years. The 8 patients with a proven malignant breast mass were aged between 39 and 66 years old. They did not have any family history of breast cancer. Only 4 patients had a family history of breast carcinoma and all proved to have a benign breast lesion. Ultrasound had a sensitivity of 100%, specificity of 85.7%, positive predictive value of 50%, negative predictive value of 100% and accuracy of 87.5% for distinguishing a malignant mass. For benign masses: 93.7% had well-defined margins, 81.3% had homogenous internal echoes, 91.7% had depth-width ratio of less than 1.0 and 89% were compressible. For malignant masses: 87.5% had either ill-defined or irregular margins, 87.5% had inhomogenous internal echoes and mixed posterior echoes, and 100% were incompressible. The majority of patients with a palpable breast mass were aged below 40 years old. Most of the patients with a malignant breast mass were aged 40 years and older. Neither a positive nor a negative family history of breast cancer had any significance on outcome. Ultrasound had high sensitivity, specificity and accuracy in distinguishing a malignant mass. The most discriminating benign ultrasound characteristic was compressibility. The most discriminating malignant ultrasound characteristic was ill-defined and irregular margins.
Matched MeSH terms: Breast Neoplasms/ultrasonography*
The purpose of this study was to evaluate the diagnostic value of qualitative and semi-quantitative assessment of ultrasound elastography in differentiating between benign and malignant breast lesions. This prospective study was conducted in two tertiary medical centers. Consecutive B-mode ultrasound and real-time elastographic images were obtained for 67 malignant and 101 benign breast lesions in 168 women. Four experienced radiologists analyzed B-mode ultrasound alone and B-mode ultrasound combined with elastography independently. Conventional ultrasound findings were classified according to the American College of Radiology Breast Imaging Reporting and Data System classification. The elastographic assessment was based on qualitative and semi-quantitative parameters (i.e., strain pattern, width ratio, strain ratio). The sensitivity and specificity of combined elastography and conventional ultrasound were significantly higher than that of conventional ultrasound alone. The sensitivity, specificity, positive predictive value and negative predictive value was 97%, 61.4%, 62.5% and 96.8%, respectively, for conventional ultrasound and 100%, 93%, 99% and 90%, respectively, for combined technique. The semi-quantitative assessment with strain ratio and width ratio in elastography were the most useful parameters in differentiating between benign and malignant breast lesions. Cut-off point values for width ratio of more than 1.1 and strain ratio of more than 5.6 showed a high predictive value of malignancy with specificities of 84% and 76%, respectively (p
Matched MeSH terms: Breast Neoplasms/ultrasonography*