glass opacity, air trapping and reticular pattern) which have been recognised in asymptomatic healthy subjects. The appearances in normal older individuals (such as large airway abnormalities, a subpleural reticular pattern and cysts) will be highlighted. Learning Objectives: 1. To become familiar with the particular HRCT findings that occupy the gray area between unequivocal health and definite disease. 2. To become familiar with these findings, with a particular focus on the effects of cigarette smoking and ageing. 3. To understand the dilemma between the increased sensitivity of HRCT to detect preclinical disease and the potential risk of overdiagnosis. Breast clinical examination provides information of tissue elasticity Young modulus E = σ / ε, where σ is the compression (stress) and ε is the deformation (strain) of the tissue. Cancers tend to be stiffer than benign lesions. Breast ultrasound elastography provides a mapping of lesion stiffness, independent of its morphologic features, displayed in real-time as a color overlay of the lesion and surrounding tissue. Two techniques are available: 1. Strain imaging, where an external compression is gradually applied to the lesion by means of the ultrasound probe, thus deforming the lesion. Results are qualitative or semi-quantitative. 2. Shear wave imaging (no external compression applied) where the ultrasound system induces mechanical vibration by using shear wave imaging. Quantitative values of Young modulus are provided. Combining elastography with B-mode can improve specificity and accuracy for BIRADS four lesions and potentially reduce breast biopsy rates. For BIRADS 3 lesions, elastography can help identifying complicated cysts and reduce FNA rates. It can also indicate a biopsy instead of follow-up in case of BIRADS 3 lesions with suspicious elastography findings. Elastography can improve delimitation of iso-echoic lesions such as infiltrating lobular carcinomas. Further applications include lymph node characterisation and monitoring neoadjuvant treatment. 3D elastography is actually in progress.