In 1895, Wilhelm Conrad Roentgen's discovery of x-rays in this laboratory revolutionised science and medicine but did
you know that x-rays may have been produced by William Morgan, a Welsh mathematician, more than a century before
Roentgen's discovery?
In 1785, Morgan was conducting experiments on electrical discharges in a vacuum when he noted that "according to
the length of time during which the mercury was boiled, the 'electric' light turned violet, then purple, then a
beautiful green...and then the light became invisible."
German physicist Wilhelm Roentgen discovered X-rays and received the Nobel prize for physics in 1901. His achievement heralded the age of modern physics and transformed medical practice.
Wilhelm Conrad Roentgen was born on March 27, 1845, in Lennep, Prussia. Educated in the Netherlands and Switzerland, Roentgen obtained his doctoral degree in physics at the University of Zürich in 1869. He conducted research and taught at the universities of Strasbourg, Giessen, Würzburg, and Munich.
In 1895 Roentgen began experiments at the University of Würzburg with an electric current flow in a partially evacuated glass tube (known as a cathode-ray tube). He noticed that, whenever the tube was in operation, a piece of barium platinocyanide in line with it gave off light. Roentgen theorised that the interaction of electrons striking the tube's glass wall formed an unknown radiation that caused the fluorescence. He called the mysterious phenomenon X radiation, or X-rays. Further experiments revealed that X radiation produces an image on photographic plates and penetrates many materials such as paper, wood, certain metals, and living tissue. For the first time physicians had a nonsurgical tool to see inside the body. The medical and scientific uses of X-rays spread quickly throughout Europe and the United States.
After receiving the Nobel Prize for his work, Roentgen continued to conduct research in several fields including elasticity, fluids, and crystals. Roentgen died on Feb. 10, 1923, in Munich, Germany. In 1895, Wilhelm Conrad Roentgen's discovery of x-rays in this laboratory revolutionised science and medicine.
After the discovery of X-rays one of the first imaging improvements was the fluoroscope. Described by an Italian physicist three months after Roentgen's X-ray discovery, it consisted of a tube with a fluorescent screen at one end and an eyepiece at the other. A body part placed between the X-ray tube and the screen produced an image even in a lighted room. A month later, Thomas Edison announced that calcium tungstate would fluoresce brighter than the original barium platinocyanide. Newspaper accounts of the day suggested that "X-ray photographs" would no longer be necessary because of the accurate images produced by the fluoroscope. History proved these predictions wrong. WE need both these types of Xray images depending on the patient's clinical problem.
British engineer Godfrey Hounsfield of EMI Laboratories in England invented CT in 1972. Hounsfield was later awarded the Nobel Prize and honoured with a Knighthood for his contributions to medicine and science. CT combined x-ray images with a computer. If you took many x-rays of the same area, at slightly different angles, a computer could put the information from the x-rays together to create a cross-sectional image.
Godfrey Hounsfield made a prototype in 1971 and the following year tried it out on a patient. The CT scanners for clinical use were first installed in 1975. The original systems were dedicated to head scanning but whole body scanners with larger patient openings became available in 1976. 30,000-CT Scanners are now installed world-wide. The first CT scanner developed by Hounsfield in his lab at EMI took several hours to acquire the raw data for a single scan (slice) and took days to reconstruct a single image from this raw data.
The latest multi-slice CT systems can collect up to 4 slices of data in about 350 ms and reconstruct a 512 x 512-matrix image from millions of data points in less than a second. An entire chest (forty 8 mm slices) can be scanned in five to ten seconds using the most advanced multi-slice CT system.
During its 25-year history, CT has made great improvements in speed, patient comfort, and resolution. As CT scan times have got faster, more anatomy can be scanned in less time. Faster scanning helps to eliminate artefacts from patient motion such as breathing or bowel movements. The new scanners provide excellent images of diagnostic quality at low doses of radiation.
The first clinical use of MRI took place in Nottingham University Hospital in 1967. The images then were of poor quality and could not be used for clinical medicine. With the advances in the computer and magnet technology the image quality improved. In the early 1980s The Clinicians were impressed by its ability to visualise abnormalities in the brain especially in the posterior fossa of the brain. CT scans by this time had established as an important diagnostic tool in the head and body imaging. CT scan uses x-rays unlike MRI, which uses magnetism.
Over the next few years, MRI became a supplementary modality to CT specially for investigating the Brain and spinal cord. Pictures from the chest and abdomen were not of diagnostic quality as they were blurred from respiratory and heart motion. With the introduction of high field magnets in the mid 1980s, came faster scan times and better techniques. Soon the superiority of MRI over CT scan was established. The improved hardware and software in computers gave MRI the ability to produce good quality images from all parts of the body.
Today MRI is the imaging modality of choice for most parts of the body. The images of the spine, musculoskeletal system, neck and mediastinal structures are of excellent quality. Recently the reduction of scanning time down to milliseconds allows for MRI fluoroscopy, which shows movement of organs and structures in real time. This may be used in interventional radiology.
Ultrasonic underwater detection systems were developed after the Titanic sank in 1912 and for the purpose of underwater navigation by submarines in World war I. Between 1914 and 1918 SONAR was in great demand for the detection of German submarines at sea. The medical use of Ultrasound started in Glasgow. Professor Ian Donald M.D. and his colleagues, working at the University of Glasgow’s Department of Midwifery were the first to apply ultrasound as a diagnostic modality in the fields of obstetrics and gynaecology, which proved to be some of the most successful early clinical applications of the technique. Many of the earlier medical uses of ultrasound had been directed towards the detection of foreign bodies, tumours and applications within echoencephalography and echocardiography with disappointing results. Donald was eventually able to obtain a Mark IV flaw detector from the Kelvin Hughes Company, which allowed him to launch a series of clinical investigations. By 1956, he was able to use the A-mode equipment to distinguish between ascites, ovarian cysts and fibroid tumours on the basis of their echo patterns.
Nuclear medicine has a complex and multifaceted heritage. The roots of nuclear medicine go back to Henri Becquerel's discovery of radioactivity in 1896. The idea that radioactivity results from the spontaneous discharge of an element was developed by Frederick Soddy in 1903. Ernerst 0. Lawrence developed the cyclotron in 1931, and paved the way for major experiments later conducted at the Radium Institute in Paris. Irene Curie, the daughter of Pierre and Marie, and her husband, Frederic Joliot, produced artificial radioactive isotopes in early 1934. After the Joliot-Curie announcement, physicists from around the world began to search for additional types of radioactive isotopes. Within twelve months, over a hundred new forms of artificial radioactive material had been discovered. The origins of Nuclear Medicine stem from many scientific discoveries, most notably the discovery of x-rays in 1895 and the discovery of "artificial radioactivity" in 1934. The first clinical use of "artificial radioactivity" was carried out in 1937 for the treatment of a patient with leukaemia at the University of California at Berkeley.
A landmark event for nuclear medicine occurred in 1946 when a thyroid cancer patient's treatment with radioactive iodine caused complete disappearance of the spread of the patient's cancer. This has been considered by some as the true beginning of nuclear medicine. Widespread clinical use of nuclear medicine, however, did not start until the early 1950s.
The value of radioactive iodine became apparent as its use increased to measure the function of the thyroid and to diagnose thyroid disease. Simultaneously, more and more physicians begin to use "nuclear medicine" for the treatment of patients with hyperthyroidism. The concept of nuclear medicine was a dramatic breakthrough for diagnostic medicine. Moreover, the ability to treat a disease with radiopharmaceuticals and to record and make a "picture" of the form and structure of an organ was invaluable.
In the mid-sixties and the years that followed, the growth of nuclear medicine as a speciality discipline was phenomenal. The advances in nuclear medicine technology and instrument manufacturers were critical to this development.
The 1970s brought the visualisation of most other organs of the body with nuclear medicine, including liver and spleen scanning, brain tumour localisation, and studies of the gastrointestinal track.
The 1980s provided the use of radiopharmaceuticals for such critical diagnoses as heart disease and the development of cutting-edge nuclear medicine cameras and computers. The use of computers, laser printers and software has transformed Nuclear Medicine. Today, there are nearly 100 different nuclear medicine procedures that uniquely provide information about virtually every major organ system within the body. Nuclear medicine is an integral part of patient care, and an important diagnostic and therapeutic speciality in the armamentarium of medical science.
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