History of Radiology

History Of Radiology

The field of radiology has drastically changed since the discovery of x-rays. Today radiology is not just limited as a diagnostics tool but interventional radiology is the forefront treatment for many serious diseases. Today's radiologists are not relegated to diagnostic roles but are actively involved in caregiving.

Radiology has evolved a long way since the discovery of x-rays by Wilhelm roentgen back in 1895. Today, the field of radiology is a comprehensive medical specialty which is not just limited to diagnostic imaging using x-rays, ultrasound, MRI, etc., but also constitutes interventional treatment methods such as angiography, angioplasty, radio frequency ablation, embolization etc. Particularly, in the treatment of vascular diseases and cancer, interventional radiology has become an effective and minimally invasive therapeutic approach. A brief history would help us get better insight into the timeline and the developments of new and important diagnostic and therapeutic tools in the field of radiology.

X-rays and Fluoroscopy

Wilhelm roentgen, the German physicist, discovered x-rays in 1895 creating what would be a revolution in medicine. Highly recognized for his achievement, the scientist was duly awarded the Nobel Prize in 1905 for his startling discovery, which was to be the precursor to modern medical diagnostic tools. It took not much time to understand the usefulness and the applications of x-rays to medical and other scientific domains. X-ray was one of the very first non-invasive tools that allowed a physician to look inside the human body without opening it. Soon after this discovery of x-rays followed the development of fluoroscopes and Thomas Edison is widely regarded as the designer of the first commercial fluoroscope using calcium tungstate as the florescent material. In 1896 it is reported that Edison and his workers had to screen more than 1800 chemical substances before arriving at calcium tungstate as the ideal material. [Otto Glassner, pg.236] in 1913, the Coolidge hot cathode tube became a standard x-ray vacuum tube with improvements over the original Crookes tube. Radiographic films appeared in 1918 replacing the previously used glass medium. However, the early radiologists were exposed to dangerous overdoses and many fatalities occurred due to occupational radiation. Only much later in the 1950's, with the development of x-ray image intensifiers and television camera did fluoroscopists find it safer as they could observe the images from a different room without the risk of exposure. [Christensen, pg. 166]

CT Scanners Ultrasound and MRI

Next major development in radiology was the invention of the CT Scanner by the British engineer Godfrey Hounsfield in the year 1972. The CT scanner employs x-rays to generate images from multiple angles and then uses the computer to produce a cross sectional image which greatly improves the diagnostics. Modern whole body CT scanners are faster, use low radiation and produce high resolution cross sectional images. The 1980's saw yet another revolution in medical diagnostics with the invention of the MRI. Magnetic Resonance Imaging as opposed to CT scans does not use x-rays but magnetism. [Peterborough and Stamford Hospitals NHS Foundation Trust]

Ultrasound scanning or sonography is the use of high frequency sound waves to create live images of the body. Ultrasound can show real time images of blood flow and tissue movements inside the human body. Though the technology in itself developed during the First World War for submarine detection purposes, the medical application was developed much later during the 1950's. Professor Ian Donald M.D from the university of Glasgow is regarded as the first person to have used ultrasound as a medical diagnostic tool in fields of gynecology and obstetrics. [Peterborough and Stamford Hospitals NHS Foundation Trust] Today we use 3-D ultrasound, which converts sound into 3 dimensional digital images. Doppler Ultrasound is used primarily to study the blood flow along the various tissues and organs of the human body. [RSNA]

The very first clinical application of MRI was in 1967 in Nottingham University Hospital but the technology had to wait until the 1980 for improvements in the computational power and the introduction of high field magnets drastically improved the performance of the MRI making it one of the diagnostic tools of choice today. [MSIT] the fact that X-rays are not used in MRI make it much safer for the patients as the radiation hazard is not there. Also, MRI provides greater contrast between the different tissues in comparison to a CT scanner offering more detailed anatomical review, better diagnostics, and improved interventional radiology. By adjusting the contrast mechanisms and other imaging parameters, the MRI allows the radiologist to obtain a highly detailed image of a particular region of study. Particularly, the MRI is highly effective as a diagnostic tool for studying the anatomy and abnormalities in the brain, spinal column and other vital regions enabling the easy identification of pathological tissues. The availability of super magnetic contrasting agents has further improved the visualization and the quality of the images. [Joseph P. Hornak]

Interventional Radiology

By the 1970's, new advancements and improvements in imaging techniques extended their application to interventional procedures in different clinical settings. Primary among these is vascular interventional radiology involving procedures such as angiography, angioplasty, chemoembolization, RF ablation (radio frequency ablation), Biopsy, etc. Today, these aforementioned interventional methods have greatly helped patients in the treatment of a wide range of cardiac conditions and cancer care. Guided procedures such as angioplasty are a quick, immediate and less invasive treatment for people suffering from blocks in heart valves. Catheterization procedure such as AV node ablation is one of the common methods for treating electrophysiological defects in the heart muscle. In cancer care, imaging guided biopsies are used to obtain tissue samples without affecting adjacent tissues. For example Transjugular liver biopsy is used to identify hepatic carcinoma without having to go through the Glisson's capsule. This procedure reduces the chances of liver bleeding. Using radiographic guidance Transcatheter chemoembolization, gene therapy and tumor ablation procedures are done effectively improving the quality of life for the patients. Similarly, image guided aspiration procedures are very effective alternatives for fluid draining under less invasive settings which would otherwise involve surgical raining. Currently Radio frequency ablation techniques are in vogue in the treatment of liver cancers and the results are encouraging. [CHARLES E. RAY, JR., M.D]