Angiography is a medical imaging technique used to visualize the blood vessels in the body, particularly the arteries and veins. The development of angiography is an interesting story that spans over a century, starting with the discovery of X-rays by Wilhelm Rontgen in 1895.[1] In 1895, the German physicist Wilhelm Röntgen (1845–1923) published pioneering research into “eine neue Art von Strahlen” (“a new kind of rays”). Röntgen’s discovery won him the first Nobel Prize in physics in 1901, and it went on to revolutionize medical diagnosis. In English, we know his new rays as X-rays, but in German and many other languages, they are still known as Röntgen radiation.
However, it is essential to mention Prof. William Crookes’ experiments which led to the cathode rays from the vacuum tubes.[2] Prof. Wilhelm Conrad Rontgen followed up on this and later discovered the X-rays.
Sir William Crookes (June 17, 1832–April 4, 1919) was a prominent British chemist and physicist who made a number of significant contributions to science in the 19th century. One of his most famous areas of research was the study of cathode rays.
In the 1870s, Crookes conducted a series of experiments that helped to establish the properties of cathode rays. He created a vacuum tube that was similar to the ones used in modern cathode ray tubes, which are found in televisions and computer monitors.
In his experiments, Crookes observed that cathode rays could produce fluorescence when they struck certain materials, such as zinc sulfide. He also found that the rays were deflected by magnetic fields, which led him to conclude that they were negatively charged.
The discovery of cathode rays led to a number of important innovations, including the development of X-rays. In 1895, Wilhelm Conrad Roentgen discovered X-rays while studying the properties of cathode rays.
Roentgen noticed that when cathode rays were emitted in a vacuum tube and directed at a metal plate, a new type of radiation was produced that could penetrate through many materials, including human flesh. He called this radiation “X-rays,” and his discovery revolutionized the field of medicine.
X-rays became an important tool for medical imaging, allowing doctors to see inside the body without surgery. They were also used in industry for nondestructive testing and in scientific research to study the structure of matter.
The innovation from cathode rays to X-rays is an example of how scientific discoveries can lead to unexpected and transformative technologies. It also highlights the importance of curiosity-driven research, which can lead to new discoveries and applications that were not initially envisioned.
In 1927, Dr. Egas Moniz,[3] a Portuguese neurologist, introduced cerebral angiography, which involved injecting a radiopaque dye into the carotid artery to visualize the blood vessels in the brain. The technique of angiography continued to evolve throughout the 20th century with new discoveries on contrast agents.
The discovery of iodine-based contrast agents[4] revolutionized the field of diagnostic imaging, and his work paved the way for the development of other types of contrast agents and imaging technologies. Today, iodine-based contrast agents are widely used in medical imaging procedures such as computed tomography (CT) scans, magnetic resonance imaging (MRI), and angiography.
In the 1940s and 1950s, improvements in X-ray technology and the development of new contrast agents allowed doctors to visualize smaller blood vessels and diagnose more complex conditions. In the 1960s and 1970s, digital subtraction angiography was developed, which allowed for more precise visualization of blood vessels by subtracting the bones and other structures from the image.
The development of CT and MRI in the 1970s and 1980s offered new possibilities for medical imaging, but angiography continued to play an important role in the diagnosis and treatment of vascular conditions. In the 1990s, the development of minimally invasive endovascular techniques, such as angioplasty and stenting, revolutionized the field of vascular surgery.
Today, angiography is an important tool in the diagnosis and treatment of a wide range of vascular conditions, including aneurysms, arterial stenosis, and venous thrombosis. The technique continues to evolve, with advances in imaging technology, contrast agents, and endovascular techniques allowing for more precise and minimally invasive procedures.
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REFERENCES
1. Tubiana M. Wilhelm Conrad Röntgen and the discovery of X-rays. Bull Acad Natl Med 1996; 180:97-108
2. Snowden H. Practical Radiography:A Hand-Book of the Applications of the X-Rays. United Kingdom: Forgotten Books; 2018
3. Artico M, Spoletini M, Fumagalli L, Biagioni F, Ryskalin L, Fornai F, et al. Egas Moniz: 90 years (1927-2017) from cerebral angiography. Front Neuroanat 2017; 11:81
4. Quader MA, Sawmiller CJ, Sumpio BE. Radio contrast agents:History and evolution Chang JB. Textbook of Angiology. New York, NY: Springer; 2000
