There have been a number of discoveries over the past several
decades that have changed the course of modern medicine. It is difficult
to imagine, for instance, the practice of medicine without the use
of antibiotics for infection and chemotherapeutic agents for neoplasms.
The world in which medicine was practiced less than two generations
ago, however, included neither of these types of agents. Other discoveries,
often made serendipitously, have also significantly changed the
way in which medicine is practiced. The discovery of the x-ray by
Wilhelm Röntgen in 1895 is one such example.
Röntgen noticed a fluorescent glow arising from some
barium-covered photographic plates while working on a Crooke’s
tube in his laboratory. Because the plates could obtain the phosphorescent glow
only by being exposed to radiation and because no form of radiation
known at the time had the ability to penetrate the black paper covering
the plates, Röntgen proposed a mysterious new form
of radiation that he called “x-rays.” A few weeks
later Röntgen presented his discovery at a physics conference
and shortly thereafter in printed form as a brief 10-page paper.
The first reports of the clinical utility of the new rays were published
within the year; Röntgen had opened the way for a new field
of medicine subsequently known as radiology. He was awarded the
first Nobel Prize in physics for his discovery.
The clinical practice of radiology initially consisted solely
of images obtained with a combination of x-rays and photographic
film. The field now includes such diverse modalities as x-rays,
nuclear medicine studies, angiography, computed tomography (CT),
ultrasound (US), and magnetic resonance imaging (MRI). In addition,
the realm of radiology has extended beyond the diagnostic arena
into therapy; radiation therapy and interventional radiology are
specialties within the field of radiology that are primarily concerned
with treatment of patients.
The form of ionizing radiation that produces x-rays can, however,
be detrimental. Case reports of radiation burns suffered as a result
of working with x-rays appeared a few months following Röntgen’s
discovery; in 1896, 23 cases of radiodermatitis were reported. The
Curie family, frequently credited with discovering natural radiation
sources in the form of radium, suffered severely from radiation-induced
disease. Marie Curie and her daughter Irene both died from leukemia,
and Pierre had leukemia when he was killed in a carriage accident.
It took many years for radiation safety to become standard in the
field of radiology and many patients as well as practitioners suffered
ill effects from what were once considered harmless rays.
Several modifications in the x-ray tube have made modern imaging
modalities significantly safer than those around the start of the
twentieth century. Proper shielding used on both x-ray tubes and patients
significantly decreases exposure of patients and surrounding personnel.
In addition, more homogeneous x-ray beams, leading to a decrease
in the amount of harmful low-energy x-rays, has significantly decreased
the risk to patients. Other developments, such as proper ...