Radiography, also known as X-ray imaging, is a medical imaging technique that uses X-rays to produce images of the internal structures of the body. It has various applications in diagnostic imaging and therapeutic procedures. Some key applications discussed in the document are mammography, which uses low-dose X-rays to screen and detect breast cancer, and fluoroscopy, which produces a continuous X-ray image on a monitor. The document provides historical context on the discovery of X-rays and development of various radiography techniques over time.

1. MR. ROHIT BANSAL
ASSISTANT PROFESSOR
MAMC (AGROHA)

2.  It is a branch of medical science which deals
with diagnosis and therapeutic applications of
radiant energy particularly of X-Rays, beta rays
and Gamma rays.
 Diagnostic imaging + therapeutic imaging
procedures.

3.  Radiographs (originally called
roentgenographs, named after the discovery
of X-rays, Sir Wilhelm Conrad Röntgen) are
produced by transmitting X-rays through a
patient.
 The X-rays are projected through the body
onto a detector; an image is formed based on
which rays pass through (and are detected)
versus those that are absorbed or scattered in
the patient (and thus are not detected).

4.  Discovered in 1895 by German physicist named
Wilhelm Roentgen.
 While studying cathode rays (stream of electrons)
in a gas discharge tube.
 He observed that another type of radiation was
produced (presumably by the interaction of
electrons with the glass walls of the tube) that
could be detected outside the tube.
 This radiation could penetrate opaque substances,
produce fluorescence, blacken a photographic
plate, and ionize a gas.
 He named his discovery "x rays" because "x"
stands for an unknown.

5.  X-rays are produced when rapidly moving electrons that have been
accelerated through a potential difference of order 1 kV to 1 MV
strikes a metal target.
 Electrons from a hot element are accelerated onto a target anode.
 The source of electrons is the cathode, or negative electrode.
Electrons are stopped or decelerated by the anode, or positive
electrode.
 Electrons move between the cathode and the anode because there is
a potential difference in charge between the electrodes.
 When the electrons are suddenly decelerated on impact, some of the
kinetic energy is converted into EM energy, as X-rays.
 Less than 1% of the energy supplied is converted into X radiation
during this process.
 The rest is converted into the internal energy of the target.

7. RADIOGRAPHY NUCLEAR MEDICINE RADIOTHERAPY
X RAY PET BRACHYTHERAPHY
CT SCAN SPECT STEROTACTIC
RADIATION THERAPY
MRI GAMMA CAMERA IMRT
USG 3D CRT
MAMMOGRAPHY PARTICLE THERAPY
DENTAL
DEXA
FLUOROSCOPY

8.  X-rays are a form of electromagnetic radiation,
similar to visible light. Unlike light, however,
x-rays have higher energy and can pass
through most objects, including the body.
Medical x-rays are used to generate images of
tissues and structures inside the body. If x-rays
travelling through the body also pass through
an x-ray detector on the other side of the
patient, an image will be formed that
represents the “shadows” formed by the
objects inside the body.

9.  In 1895, Wilhelm Roentgen, a professor of physics in Bavaria,
was working on an experiment with cathode ray tubes to learn
if cathode rays could travel through a vacuum tube. He
applied a high voltage to the tube and noticed that the positive
and negative electrodes within the tube caused it to emit light.
 He then covered the tube with black paper to see if the light
would shine through, and a nearby screen treated with a
chemical called barium platinocyanide began to glow.
 He concluded that a type of radiation must be at work from
inside the tube. He soon learned that the rays had very short
wavelengths that enabled them to pass through human flesh
and leave a shadow of the underlying bones on the screen.
 He named this radiation X-ray, with X standing for unknown.
He created the very first X-ray by capturing the image of the
bones of his wife’s hand. When she looked at the image, his
wife is said to have cried, “I have seen my death!”
 For his discovery of radiation, Roentgen won the very first
Nobel Prize in physics in 1901. But he couldn’t have known
that his discovery would become one of the cornerstones of
modern medicine.

10.  Introduced in the mid-1990s, X-ray systems capture higher-quality images at
higher resolutions than ever before, all while requiring less time to capture.
Digital X-ray systems have revolutionized diagnostic radiology. Many of the
improvements in X-ray systems are a direct result of the advantages of digital
capture over traditional film capture.
 Digital X-ray systems have a higher dynamic range than film, which allows
for clearer, more detailed images. Since digital X-ray systems do not require
extensive processing, there is a significant reduction in the time it takes to
deliver images to radiologists and ultimately patients. Digital capture also
improves image-processing capabilities such as spatial zooming and contrast
enhancement. Finally, there are more convenient storage options for digital
images than film, and digital storage reduces the amount of polluting waste
products.
 Given all of the improvements over the years, X-ray systems have become
very complex and require an analog front end (AFE), a digital signal
processor (DSP), an LCD, power supply design, sensor controls and a few
other external components. The readout electronics required for direct
imaging to convert a charge in a flat panel detector (FPD) to digital data.

13.  A computerized X-ray imaging procedure in
which a narrow beam of X-rays is aimed at a
patient and quickly rotated around the body,
producing signals that are processed by the
machine’s computer to generate cross-sectional
images—or “slices”—of the body.
 These slices are called tomographic images and
contain more detailed information about the
internal organs than conventional X-rays.

14.  The first clinical CT scanners were installed between 1974
and 1976. The original systems were dedicated to head
imaging only, but "whole body" systems with larger
patient openings became available in 1976. CT became
widely available by about 1980. There are now about 6,000
CT scanners installed in the U.S. and about 30,000 installed
worldwide.
 The first CT scanner developed by Hounsfield in his lab at
EMI took several hours to acquire the raw data for a single
scan or "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.

15.  The first ever human patient to benefit from the brain
scanner was a woman believed to be suffering from a
brain tumor. The first doctor to utilize the machine on
October 1, 1971, was James Ambrose. The entire process
took days to complete as the scanner required many
hours to obtain the raw data for a single scan, or “slice.”
Afterward, a few more days were needed to reconstruct
an image from the acquired data.
 During its 25-year history, CT has made great
improvements in speed, patient comfort, and resolution.
As CT scan times have gotten faster, more anatomy can
be scanned in less time. Faster scanning helps to
eliminate artifacts from patient motion such as
breathing or peristalsis. CT exams are now quicker and
more patient-friendly than ever before. Tremendous
research and development has been made to provide
excellent image quality for diagnostic confidence at the
lowest possible x-ray dose.

16. CT technology has evolved from first-generation to
advancements like cone beam CT, multidetector CT, higher
slice system, new detector technology, spectral CT imaging,
data integration, dual source scanner, dual energy, etc.
Higher simultaneous 0.5 mm slice and give isotopic
volumetric data with better resolution, thin slice volume
data reconstruction, post processing and advanced
visualization algorithms allow extraction of specific body
parts.
Low-dose CT imaging techniques have been a significant
focus over the past several years in an effort to alleviate
concerns about patient exposure to X-ray radiation
associated with widely used CT scans.

19.  A non-invasive imaging technology used to
investigate anatomy and function of the body
in both health and disease without the use of
damaging ionizing radiation.
 It is often used for disease detection, diagnosis,
and treatment monitoring.
 It is based on sophisticated technology that
excites and detects changes in protons found in
the water that makes up living tissues.

20.  he history of MRI technology begins with the study
of magnetic resonance or how electrons’ and
atoms’ nuclei respond to magnetism.
 In the 1930s, physicist I.I. Rabi developed a way to
measure the magnetic properties (spin) and sodium
movement. In his work, Rabi developed a form of
MR imaging called nuclear magnetic
resonance (NMR). That work became the basis of
medical MRIs.
 During the 1940s, physicists Felix Bloch and
Edward Purcell, working independently, studied
the atomic and molecular magnetic resonance
properties of solids and liquids. Their research later
allowed MRI scanners to use the body’s water
content to develop magnetic resonance images.

21.  In 1952, Purcel and Bloch won the Nobel Prize in physics.
 Damadian discovered (1969) that it’s possible to distinguish
between cancer cells and healthy tissue through nuclear
magnetic resonance (NMR) because of the differences
in relaxation times between the two. From that research, he
proposed an MR body scanner in 1969.
 In 1972, Damadian filed the first patent of MRI technology.
Upon approval of his patent in 1974, Damadian designed and
built a full-body MRI machine. The first MR (magnetic
resonance) scanning machine, which he called “Indomitable,” is
now in the Smithsonian.
 On July 3, 1977, Damadian achieved the first human
NMR image — a cross-section of his postgraduate assistant
Larry Minkoff’s chest. The image revealed Minkoff’s heart,
lungs, vertebrae, and musculature and became the method
known as magnetic resonance imaging (MRI).
 In 1978, Damadian founded FONAR Corporation (field focused
nuclear magnetic resonance). FONAR produced the first
commercially available MRI machine in 1980.

22.  Higher Magnetic Field Strength.
 Can able to perform Perfusion studies, Diffusion
studies, Function MRI, Spectroscopic studies etc.
 Open bore MRI for Claustrophobic patients.
 Latest MRI scanner can give a variety of image
types and angles of a single area on the body
without the patients having to move around inside
the scanner.
 The latest MRI scanner uses more than 250 shades
of gray to differentiate various parts of a tissue.
This makes it easier for doctors to study the scans
and quickly depict varying tissues and identify the
problem.

25.  A form of acoustic energy, or sound, that has a
frequency that is higher than the level of human
hearing.
 As a medical diagnostic technique, high frequency
sound waves are used to provide real-time medical
imaging image inside the body without exposure to
ionizing radiation.
 As a therapeutic technique, high frequency sound
waves interact with tissues to destroy diseased tissue
such as tumors, or to modify tissues, or target drugs to
specific locations in the body.

26. Date Historical Achievement or Event
1794
Physiologist Lazzaro Spallanzani was the first to study echolocation among bats,
which forms the basis for ultrasound physics.
1877
Brothers Pierre and Jacques Currie discover piezoelectricity. Ultrasound
transducers (probes) emit and receive sound waves by way of the piezoelectric
effect.
1915
Inspired by the sinking of the Titanic, Physicist Paul Langevin was
commissioned to invent a device that detected objects at the bottom of the sea.
Laugevin invented a hydrophone – what the World Congress Ultrasound in
Medical Education refers to as the “first transducer”.
1920s-
1940s
Sonography was used to treat members of European soccer teams as a form of
physical therapy, to appease arthritic pain and eczema and to sterilize vaccines,
states Joan Baker who holds several ARDMS ultrasound certifications.
1942
Neurologist Karl Dussik is credited with being the first to use sonography for
medical diagnoses. He transmitted an ultrasound beam through the human
skull in attempts of detecting brain tumors.
1948
George D. Ludwig, M.D., an Internist at the Naval Medical Research Institute,
developed A-mode ultrasound equipment to detect gallstones.

27. 1949-
1951
Douglas Howry and Joseph Holmes, from the University of Colorado, were some
of the leading pioneers of B-mode ultrasound equipment, including the 2D B-
mode linear compound scanner. John Reid and John Wild invented a handheld B-
mode device to detect breast tumors.
1953
Physician Inge Edler and Engineer C. Hellmuth Hertz performed the first
successful echocardiogram by employing an echo test control device from a
Siemens shipyard.
1958 Dr. Ian Donald incorporated ultrasound into the OB/GYN field of medicine.
1966
Don Baker, Dennis Watkins, and John Reid designed pulsed Doppler ultrasound
technology; their developments led to imaging blood flow in various layers of the
heart.
1970s
The 1970s saw many developments including the continuous wave Doppler,
spectral wave Doppler and color Doppler ultrasound instruments.
1980s
Kazunori Baba of the University of Tokyo developed 3D ultrasound
technology and captured three-dimensional images of a fetus in 1986.
1989
Professor Daniel Lichtenstein began incorporating lung and general sonography
in intensive care units.
1990s
Starting in the 1980s, ultrasound technology became more sophisticated with
improved image quality and 3D imaging capabilities. These improvements
continued into the 1990s with the adoption of 4D (real time) capabilities.
Ultrasound guided biopsies (endoscopic ultrasounds) also began in the 1990s.

28. Ultrasound is now being used in interventional procedures generally
dominated by computed tomography (CT) and magnetic resonance
imaging (MRI). And although many interventional physicians still rely
on CT and MRI for lung procedures, it has become common for
interventionists to use ultrasound instead of CT for image-guided
biopsies and ablations.
Advancements in Volumetric Ultrasound
Ultrasound was previously only able to capture a single imaging plane,
but today it can acquire volumes.
Development of New Technologies
Recent development is the use of ultrasound contrast agents. Contrast-
enhanced ultrasound (CEUS) grants much more sensitivity for the
detection of tumors, allowing ultrasound use to expand into many of the
functions currently performed by CT and MRI.

31.  An X-ray imaging method used to image the
breast for the early detection of cancer and
other breast diseases.
 It is used as both a diagnostic and screening
tool.
 Mammography is specialized medical imaging
that uses a low-dose x-ray system to see inside
the breasts.

32. Eighteen years after the discovery of x-rays in 1895, a
German surgeon began a study of 3,000
mastectomies and wondered if by using these newly
discovered rays, he could correlate known cancerous
tissue of breast specimens to radiographs taken of the
same breast. He discovered micro-calcifications on the
images associated with those specimens with known
breast cancer pathology. In 1913 he wrote, “Roentgen
photographs (x-rays) of excised breast specimens give a
demonstrable overview of the form and spread of
cancerous tumors.” In 1949, Raul Leborgne, a
radiologist in Uruguay, introduced the medical
community to the compression technique in breast
imaging, ushering in the modern mammogram. In the
late 1950s, a physician in Houston, Texas detailed a
new technique using fine-grain intensifying screens
that produced even clearer images of the breast.
Finally, in 1969, dedicated mammography units
became available for use around the world.

33. Three recent advances in mammography include digital mammography,
computer-aided detection and breast tomosynthesis.
Digital mammography, also called full-field digital mammography
(FFDM), is a mammography system in which the x-ray film is replaced by
electronics that convert x-rays into mammographic pictures of the breast.
Computer-aided detection (CAD) systems search digitized
mammographic images for abnormal areas of density, mass,
or calcification that may indicate the presence of cancer.
Breast tomosynthesis, also called three-dimensional (3-D) mammography
and digital breast tomosynthesis (DBT), is an advanced form of breast
imaging where multiple images of the breast from different angles are
captured and reconstructed ("synthesized") into a three-dimensional
image set.

36.  Fluoroscopy is a type of medical imaging that
shows a continuous X-ray image on a monitor,
much like an X-ray movie.
 During a fluoroscopy procedure, an X-ray
beam is passed through the body.
 The image is transmitted to a monitor so the
movement of a body part or of an instrument
or contrast agent (“X-ray dye”) through the
body can be seen in detail.

37. The beginning of Fluoroscopy was on November 8,
1895 when a German physicist named Wilhelm
Rontgen noticed a platinocyanide screen flourishing as
a result of X-rays. The first fluoroscopes were created
after several months of this discovery. Early
fluoroscopes were cardboard funnels with an open at
the narrow end for the observers’ eyes while the wide
end was closed with a thin cardboard piece that had
been covered on the inside layer of fluorescent metal
salt. This procedure had to be done in a dark room due
to limited light produced from the fluorescent screens.
As a result, there were radiation doses to the radiologist
looking through the screen. To prevent this, red
adaption goggles were developed by Wilhelm Rontgen
in 1919, so that the radiologist can function normally
during the procedure.

38.  The inventions of the X-ray intensifier and the television
camera in the 1950’s enhanced the technology of
fluoroscopy. The red adaption goggles allowed the light
produced by fluorescent screen to allow it to be seen in a
lighted room. The camera made radiologists view the
image on a monitor in a room away from the risk of
radiation exposure. Modern improvements were made
later on in screen phosphors, image intensifiers and even
flat panel detectors which allowed an increase in image
quality while decreasing the radiation dose to the patient.
 Modern fluoroscopes use CSL screens and produce
images with less radiation. Now, modern image
intensifiers use cesium iodide phosphor which is put
directly on the photocathode of the intensifier tube. The
output image is 105 times brighter than the input image.

39. In modern systems, the fluorescent screen is coupled to an
electronic device that amplifies and transforms the
glowing light into a video signal suitable for presentation
on an electronic display. One benefit of the modern
system compared to the earlier approach is that the
fluoroscopist need not stand in close proximity to the
fluorescent screen in order to observe the live image. This
results in a substantial reduction in radiation dose to the
fluoroscopist. Patients receive less radiation dose as well,
because of the amplification and overall efficiency of the
imaging system.

42.  Dental radiographs are commonly called X-
rays. Dentists use radiographs for many reasons: to find
hidden dental structures, malignant or benign masses, bone
loss, and cavities.
 A radiographic image is formed by a controlled burst of X-
ray radiation which penetrates oral structures at different
levels, depending on varying anatomical densities, before
striking the film or sensor.
 Teeth appear lighter because less radiation penetrates them
to reach the film.
 Dental caries, infections and other changes in the bone
density, and the periodontal ligament, appear darker
because X-rays readily penetrate these less dense structures.
 Dental restorations (fillings, crowns) may appear lighter or
darker, depending on the density of the material.

43.  Dentists were also quick to use the new (X-Ray)
technology. Prominent New Orleans dentist C.
Edmund Kells took the first dental x-ray of a
living person in the U.S. in 1896.
 Technological advancements, such as faster
film speed, improved image quality, and
patient comfort. The influence of institutions,
such as the American Dental Association and
Victor X-Ray Company, helped establish x-ray
technology as an accepted and necessary tool in
dentistry.
 Dentists began to use x-rays regularly in the
1950s. Today, x-rays are often a normal part of
a routine dental exam.

44. There are currently three types of digital radiography
systems available for the use in dental imaging: 1) CCD -
Charge-Coupled Device (direct system), 2) CMOS –
Complementary Metal Oxide Semiconductor (direct
system), and 3) PSP - photostimulable phosphor (indirect
system). The manufacturers of digital dental imaging are
dynamic and continuously changing as the dental
profession has been slow to accept this technology.

47.  A positron emission tomography (PET) scan is an imaging test
that can help reveal the metabolic or biochemical function of your
tissues and organs.
 The PET scan uses a radioactive drug (tracer) to show both normal
and abnormal metabolic activity.
 A PET scan can often detect the abnormal metabolism of the tracer
in diseases before the disease shows up on other imaging tests,
such as computerized tomography (CT) and magnetic resonance
imaging (MRI).
 The tracer is most often injected into a vein within your hand or
arm.
 The tracer will then collect into areas of your body that have
higher levels of metabolic or biochemical activity, which often
pinpoints the location of the disease.
 The PET images are typically combined with CT or MRI and are
called PET-CT or PET-MRI scans.

48. In 1953 William H. Sweet and Gordon L.
Brownell at Massachusetts General Hospital,
Boston, described the first positron imaging
device, and the first attempt to record three
dimensional data in positron detection in their
paper entitled "Localization of brain tumors with
positron emitters”.. This was the beginning
of positron emission tomography (PET).

49. New Radiotracers
While the FDG radiotracer agent is still the gold standard, researchers are
working on new tracers that would allow PET scans for different uses.
Hybrid PET/MR Machines
The great advantage of MR/PET will be simultaneous functional imaging
which you don’t have from PET/CT, which is sequential
PET for Monitoring
PET scanning is helping monitor the therapy of patients with tuberculosis
and able to quantify the extent of the disease with a number. It will be
monitoring patients more frequently to determine how well the treatment
is working.