| Date | Development or Discovery |
| c. 400 BC | Disease concept introduced by Greek physician Hippocrates. |
| 1612 | Medical Thermometer devised by Italian physician Sanctorius |
| c. 1660 | Light microscope developed by Dutch naturalist Antohj van Leeuwenhoek |
| 1810 | Stethoscope invented by French physician Rene' Laennec. |
| 1850 - 1900 | Germ theory of disease proposed by French scientist Louis Pasteur and developed by German bacteriologist Robert Koch. |
| 1895 | X-rays discovered by German physicist Wilhelm Conrad Roentgen. He also produced the first x-ray picture of the body (his wife's hand) in 1895. |
| 1900 | Chest x-ray, widespread use of the chest x-ray made early detection of tuberculosis (which was the most common cause of death) a reality. |
| 1906 | X-ray contrast medium. First contrast filled image of the renal system (kidneys). |
| 1910 | Barium sulfate introduction of as contrast agent for gastro-intestinal diagnosis. |
| 1910-1912 | Theory of Radioactivity published by Marie Curie and investigation of x-ray radiation for patient therapy (e.g. treatment of cancer). |
| 1906 | Electrocardiograph (ECG) invented by Dutch physiologist Willem Einthoven to monitor and record the electric signature of the heart. |
| 1924 | Radiographic imaging of the gallbladder, bile duct and blood vessels for the first time. |
| 1929 | Cardiac catheterization first performed by Forssmann on himself. |
| c. 1932 | Transmission electron microscope (TEM) constructed by German scientists Max Knoll and Ernst Ruska. |
| 1945 | Coronary artery imaging. Visualization of (blood vessels that feed the heart). |
| 1950 | Nuclear Medicine applied imaging the kidneys, heart, and skeletal system. |
| 1955 | X-ray Image Intensifier-Television units to allow dynamic x-ray imaging of moving scenes. These fluoroscopic movies provided new information of the beating heart and its blood vessels. |
| c. 1955 | Panoramic x-ray images of the entire jaw and teeth. |
| 1957 | Fiber endoscopy pioneered by South African-born physician Basil Hirschowitz at the University of Michigan. |
| 1960 | Ultrasound imaging is developed to look at the abdomen and kidneys, fetal baby, carotid blood vessels and heart. |
| 1970 | X-ray mammography finds widespread application in imaging the breasts. |
| 1972 | Computed Tomography (CT) scanning invented by British engineer Godfrey Hounsfield of EMI Laboratories, England, and South African born physicist Allan Cormack of Tufts University, Massachusetts. |
| 1975 | Chronic villus sampling developed by Chinese gynecologists as an aid to the early diagnosis of genetic disorders. |
| 1976 | Coronary Angioplasty was introduced by surgeon Andreas Gruentzig at the University Hospital, Zurich, Switzerland. This technique uses x-ray fluoroscopy to guide the compression of plaques and minimize the dangerous constriction of the heart vessels. |
| 1978 | Digital radiography: the TV signal from the x-ray system is converted to a digital picture which can then be enhanced for clearer diagnosis and stored digitally for future review. |
| 1980 | Magnetic Resonance Imaging (MRI) of the brain was first done on a clinical patient. MRI was developed by Paul Lauterbur and scientists at Thorn-EMI Laboratories, England, and Nottingham University, England. |
| 1984 | 3-Dimensional image processing using digital computers and CT or MR data, three dimensional images of bones and organs were first made. |
| 1985 | ClinicalPositron Emission Tomography (PET) scanning developed by scientists at the University of California. |
| c. 1985 | Clinical Networks were first implemented to allow digital diagnostic images to be shared between physicians via computer network, allowing a doctor in Boston to review a CT examination from a patient in Beijing, China. |
| 1989 | Spiral CT allows fast volume scanning of an entire organ during a single, short patient breath hold of 20 to 30 seconds. Spiral CT had caused a renaissance in CT and lead the way tosignificant developments like CT Angiography. |
| 1989 | MR Angiography developed and clinically available to allow non-invasive imaging of the blood vessels without radiation or contrast injection. |
| 1993 | Echo Planar MR Imaging (EPI) developed and clinically available to allow MR systems to provide early detection of acute stroke. EPI also makes possible functional imaging, for instance of brain activity allowing doctors to investigate the function of different centers of the mind. |
| 1993 | Open MRI Systems developed to allow MR scanning of severely claustrophobic or obese patients who could not tolerate convention MR imaging in a close bore system. |


