RADIOGRAPHY AND MAMMOGRAPHY.pptx

1. Radiography and mammography
Radiology chapter 2 

2. Introduction to Radiography:
 Radiography is an imaging technique using X-rays, gamma rays,
or similar ionizing radiation and non-ionizing radiation to view
the Internal form of an object.
 It is based on the principle that radiation is absorbed and scattered
as it passes through an object. If there are variations in thickness
or density (e.g. due to defects) in an object, more or less radiation
passes through and affects the film exposure.
 It is used to diagnose or treat patients by recording images of the
internal structure of the body to assess the presence or absence of
disease, foreign objects, and structural damage or anomaly.

3. Production of x-rays
 X-ray tubes produce x-ray photos by accelerating a steam of
electrons and colliding them with a heavy metal target.
 X-ray radiation with a continuous spectrum of energies is
produced with a range of few keV to a maximum of energy of
electron beam.
 When an X-ray photon with high energy knocks out an electron
from an inner shell of atom , the ejected electron s called
photoelectron and this effect is known as photoelectric effect.
 The atom will release energy by the emission of electron.

4. X-ray radiography:
 X-rays are produced by an x-ray generator system. These systems
typically include an x-ray tube head, a high voltage generator and
a control console.
 X-rays are produced by establishing a very high voltage between
two electrodes , called the anode and cathode.
 To prevent arcing, the anode and cathode are located inside a
vacuum tube, which is protected by a metal housing.
 The cathode contains a small filament much like the filament in
bulb.

5. Cont.
 Current is passed through the filament which heats it . The heat
causes energy to be stripped off.
 The high voltage causes these free electrons to be pulled towards
a target material (usually tungsten) located in the anode.
 The electrons impact against the target.
 This impact causes an energy exchange which causes x-rays to be
created.

6. Gamma rays radiography:
 Gamma rays are produced by radioisotope.
 A radioisotope has an unstable nuclei that does not have enough
binding to hold the nucleus together.
 The spontaneous breakdown of an atomic nucleus resulting in the
release of energy and matter is known as radioactive decay.
 Isotopes emit radiations in a few discrete wavelength.
 Cobalt-60 will emit 1.25MeV x-ray wavelength.
 These high energy wavelengths with make it possible to penetrate
thick materials with a relatively short exposure time.

7.  Unlike x-rays , which are produced by a machine, gamma rays
can’t be turned off. Radioisotopes used for gamma radiography
are encapsulated to prevent any kind of leakage.
 The radioactive capsule is attached to a cable to form which is
often called a pigtail.
 The pigtail has a special connector at the other end that attaches to
a drive cable.
 A device called the camera is used to store ,transport and expose
the pigtail containing the radioactive material. The camera
contains the shielding material which reduces the radiographer’s
exposure to radiation during use.

8.  A device cable is connected
to the other end of the
camera. This cable
controlled by the
radiographer , is used to
force the radioactive
material out into the guide
tube where the gamma rays
will pass through the
specimen and expose the
radioactive device.

9. Imaging modalities:
 Film or paper radiography:
 a two-dimensional latent image from the projected
radiation is produced on a sheet of film or paper that has
been exposed to the unabsorbed radiation passing
through the test piece. This technique requires
subsequent development of the exposed film or paper so
that the latent image becomes visible for viewing.

10. Cont.
 Real-time radiography:
 A two-dimensional image can be immediately displayed on a
viewing screen or television monitor. This technique doesn’t
involve the creation of a latent image instead. The unabsorbed
radiation is converted into an optical or electronic signal. Which
can be viewed immediately or can be processed in near real-time
with electronic and video equipment.
 Others are :
 Digital radiography
 Computed radiography

11. Procedure:
 During a radiographic procedure, an x-ray beam is passed through
the body. A portion of the x-rays are absorbed or scattered by the
internal structure and the remaining x-ray pattern is transmitted to
a detector so that an image may be recorded for later evaluation.
The recoding of the pattern may occur on film or through
electronic means.
 It is used to diagnose or treat patients by recording images of the
internal structure of the body to assess the presence or absence of
disease, foreign objects, and structural damage or anomaly.

12. Uses:
 Radiography is used in many types of examinations and procedures
where a record of a static image is desired. Some examples include
 Dental examination
 Verification of correct placement of surgical markers prior to invasive
procedures
 Mammography
 Orthopedic evaluations
 Spot film or static recording during fluoroscopy
 Chiropractic examinations

13. Uses: x-rays and gamma rays
 It is cheaper and simple technique.
 It has lower radiation compare to CT scan.
 X-rays are not absorbed very much by air, hence specimen need not be
in an evacuated chamber.
 It helps to diagnose tumors easily without the need of surgery.
 Uses of Gamma Rays:
 Sterilize medical equipment.
 Sterilize food (irradiated food)
 Used as tracers in medicine.
 Radio Therapy- In oncology, to kill cancerous cells.
 Gamma-Ray Astronomy.

14. Benefits:
 noninvasively and painlessly help to diagnose disease
and monitor therapy;
 support medical and surgical treatment planning; and.
 guide medical personnel as they insert catheters, stents,
or other devices inside the body, treat tumors, or remove
blood clots or other blockages.

15. Risks:
 the major risks associated with radiography are the
small possibilities of:
 developing a radiation-induced cancer or cataracts some
time later in life, and
 causing a disturbance in the growth or development of
an embryo or fetus (teratogenic defect) when performed
on a pregnant patient or one of childbearing age.

20. Contraindications:
Pregnancy
Bowel perfusion
Weight of patients

21. Mammography introduction:
 Mammography (also called mastography) is the process of using
low-energy X-rays (usually around 30 kVp) to examine the
human breast for diagnosis and screening.
 The goal of mammography is the early detection of breast cancer,
typically through detection of characteristic masses or
microcalcifications.
 As with all X-rays, mammograms use doses of ionizing radiation
to create images. These images are then analyzed for abnormal
findings

22. Types:
 Screening mammogram:
A screening mammogram is an X-ray of the breast used to detect
breast changes in women who have no signs or symptoms of breast
cancer. It usually involves 2 X-rays of each breast. Using a
mammogram, it is possible to detect a tumor that cannot be felt.
Diagnostic mammogram:
A diagnostic mammogram is an X-ray of the breast used to
diagnose unusual breast changes, such as a lump, pain, nipple
thickening or discharge, or a change in breast size or shape. A
diagnostic mammogram is also used to evaluate abnormalities
detected on a screening mammogram. It is a basic medical tool and
is appropriate in the workup of breast changes, regardless of a
woman's age.

23. Breast tomosynthesis:
 Breast tomosynthesis, also called three-dimensional (3-D)
mammography and digital breast tomosynthesis (DBT), is an
advanced form of breast imaging, or mammography, that uses a
low-dose x-ray system and computer reconstructions to create
three-dimensional images of the breasts.
 Tomosynthesis, which people may refer to as digital breast
tomosynthesis (DBT), uses the same technology as a regular
mammogram. However, while traditional mammograms are 2-D
and provide a flat image, tomosynthesis creates a 3-D image.
Standard mammograms and tomosynthesis both use X-rays.

24. Breast tomosynthesis also results in:
 Earlier detection of small breast cancers that maybe hidden on a
conventional mammogram.
 Greater accuracy in pinpointing the size, shape and location of
breast abnormalities .
 Fewer unnecessary biopsies or additional tests.
 Detecting multiple breast tumors.
 Clearer image of abnormalities.

26. Procedure:
 During mammography, a specially qualified radiologic
technologist will position your breast in the mammography unit.
Your breast will be placed on a special platform and compressed
with a clear plastic paddle. The technologist will gradually
compress your breast.
 You will be asked to change positions between images.
 You must hold very still and may need to hold your breath for a
few seconds while the technologist takes the x-ray. This helps
reduce the possibility of a blurred image. The technologist will
activate the x-ray machine.
 The examination process should take about 30 minutes.

27. Breast compression is necessary in order
to:
 Even out the breast thickness so that all of the tissue can be
visualized.
 Spread out the tissue so that small abnormalities are less
likely to be hidden by overlying breast tissue.
 Allow the use of a lower x-ray dose since a thinner amount
of breast tissue is being imaged.
 Hold the breast still in order to minimize blurring of the
image caused by motion.
 Reduce x-ray scatter to increase sharpness of picture.

28. Indication:
 Pain/tenderness
 Swelling
 Nipple discharge
 Calcification
 Benign or malignant tumor
 Lymph node enlargement

29. Contraindications:
 Breast implant
 Severe nipple discharge
 Large palpable mass
 Inflammation
 Women within reproductive age
 15-40 (benefit over risk)