1 - Skeletal system: general 2 - Joints 3 - Appendicular skeleton 4 - Head and neck 5 - Spine 6 - Lower respiratory tract 7 - Cardiovascular system 8 - Other thoracic structures - pleural cavity, mediastinum, thoracic oesophagus, thoracic wall 9 - Gastrointestinal tract 10 - Urogenital tract 11 - Other abdominal structures - abdominal wall, peritoneal and retroperitoneal cavities, parenchymal organs 12 - Soft tissues - Radiographic faults - Ultrasound terminology and artefacts - Geographic distributions of diseases