Transcript Chapter 48 - cloudfront.net

Chapter 48
Radiology & Diagnostic
Imaging
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Learning Objectives
 Define and use the terms in the
glossary
 List the four views for chest X-ray,
describing patient positioning for each
 Discuss patient positioning for back,
neck, and extremity X-ray and how to
comfort the patient in pain
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Learning Objectives
 Explain the patient preparation
necessary for mammography
 Explain the difference between filmscreen radiography and fluoroscopy
 Explain the function of contrast media
and special considerations of their use
with patients
 Describe how ultrasound waves create
images of soft tissue and internal
organs
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Radiography and the Medical
Assistant
 Radiography—diagnostic technique
using radiation to produce image of
body
 Radiology—branch of medicine using
radioactive substances for diagnosing
and treatment
 Radiograph—image produced by
radiation
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Radiography and the Medical
Assistant
 Provider explains images to patient
 Medical assistant does not interpret
images
 Medical assistant can explain
procedures to patient regarding
terminology
 X-ray positioning, preparation for the
test, follow-up care
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X ray
 Discovered by
Roentgen in 1895
 Light wave causes
ionization creating
electromagnetic
radiation
 Ionization causes
fluorescence of
certain substances
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X ray
 X-ray film blackens
on exposure to light
 Radiopaque—
impenetrable by
electromagnetic
radiation
 Radiolucent—
penetrable by
electromagnetic
radiation
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X-ray Film
 Manufactured to be sensitive to energy
from X-ray machine
 Coated with photosensitive fluid on both
sides
 Stored in clean, cool, dry area
 Film has expiration date, store with
expiration date visible
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X-ray Views
 Views are named for direction of beam
in relation to body part that beam
passes through
 Five major views
 Posteroanterior, anteroposterior, right
lateral, left lateral, oblique
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X-ray Views
 Patient’s back toward
X-ray tube on
machine produces
posteroanterior (PA)
chest film
 Extremities have
same terminology
(A) posteroanterior
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X-ray Views
(B) anteroposterior
(C) right lateral
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X-ray Views
(D) left lateral
(E) oblique
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Patient Preparation
 Medical assistant explains procedure to
patient
 Asks patient if pregnant
 Instructs patient to remove all jewelry
 Positions patient appropriately
 Four major areas to X-ray are chest,
lower back, cervical spine, and
extremities
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Chest X-ray
 Patient stands or lays down
 Patient remains still
 Patient takes in deep breath and holds
until directed to release
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Lower Back and Cervical Spine
X-ray
 Lower back
 Patient stands or
lays down
 Patient remains
still
 No need to take a
deep breath
 Cervical spine
 Patient stands
 X-ray tube at
patient’s head
and neck level
 Open or closed
mouth X-ray as
ordered
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Extremity X-ray
 Patient sits or lies on
X-ray table
 Place film under
affected body part
 Drape with lead
apron
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Extremity X-ray
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Mammography
 X-ray of breast
 First at age 40
 Patient faces
mammogram
machine
 Breast placed on flat
plate
 Machine applies
pressure
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Patient Preparation for
Mammography
 Give patient written and verbal instructions
 Patient should avoid caffeine several days
prior to test
 Do not schedule close to patient’s menstrual
cycle
 Patient should refrain from using lotions,
powders, and deodorants the day of the test
 Patient must stand for 15 minutes for test
 Explain that there may be some discomfort
 Patient’s clothing from the waist up will be
removed
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Fluoroscopy
 X-ray producing moving picture
 Requires contrast medium administered
orally, by injection, or by enema
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Fluoroscopy
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Patient Preparation
 Specific preparation for diagnostic
testing with contrast medium
 Instructions given in writing
 Some require prescription for pretest
medication
 Discuss possibility of allergies to iodine
and shellfish
 Alternative testing may be indicated
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Computer Imaging
Also called digital radiographic imaging
Uses alternative to X-ray film
Provides clearer, error-free images
Computer creates image while patient is
having test
 Tests include ultrasound, magnetic
resonance imaging, computed
tomography, nuclear medicine
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Ultrasound
 High-frequency
sound waves create
image of soft tissue
and internal organs
 Noninvasive
procedure
 Safe to view fetus
 Transducer passes
over skin with
conducting gel
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Patient Preparation
 Abdominal ultrasound—view liver,
gallbladder, kidneys, pancreas, spleen,
aorta
 NPO midnight day before test
 Pelvic ultrasound—view various
structures in pelvis
 Done transvaginally or transrectally
 Patient’s bladder must be full
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Patient Preparation
 Fetal ultrasound—view developing fetus
 Determine gestational age, sex of fetus,
measure head circumference, assess
position of placenta
 Patient in early-stage pregnancy should
have a full bladder
 Patient in later-stage pregnancy does
not need to have a full bladder
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Magnetic Resonance Imaging
 Magnetic resonance imaging (MRI)
 Strong magnetic field and radio waves
are used to view anatomical structures
 Creates three-dimensional image
 Shows blood clots, nerve damage, torn
ligaments and tendons, other soft tissue
abnormalities
 Noninvasive
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Patient Preparation
 No dietary restrictions for MRI
 Patient can continue medications
 Ask patients about medical devices with metal
in their bodies; pacemaker, surgical rods or
pins, dental bridges
 Determine if patient’s occupation involves
small particles of metal—may require orbit Xrays prior to proceeding with MRI
 Inquire if patient is pregnant or claustrophobic
 Can patient lie still for at least 30 minutes
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MRI Scanners
 Patient must lie on back for at least 30
minutes
 Patient may use earplugs
 Open or closed MRI
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MRI Scanners
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Computed Tomography
 Computed tomography (CT) or
computerized axial tomography (CAT)
 Uses X-rays to produce cross-sectional
views
 Uses two-dimensional images to create
three-dimensional image that can
rotate in many directions
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CT Scan
 May involve use of
contrast medium
introduced through
IV
 Technologist follows
path of dye on the
scan
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Nuclear Medicine
 Techniques that use radioactive
material for diagnosis and treatment
 Radiation therapy used to treat cancer
 Positron emission tomography (PET)
scanning technique used for diagnosis
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Radiation Therapy
 Delivers specific dose of radiation to
specific area of body to destroy cancer
cells
 External radiation therapy—dose is
delivered a specific distance from
tumor, given over a period of weeks or
months
 Internal radiation therapy—implanted
containers of radioactive material near
tumor, or oral radioactive substances
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Patient Preparation
 Patients may experience adverse effects
 Provide strategies for reducing symptoms
 Encourage patient to eat cool, soft foods in
small portions
 Encourage patient to eat on days he or she
does not receive radiation
 Encourage patient to plan time for sleeping
and relaxing after treatment
 Advise patient to arrange transportation to
and from treatment
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Positron Emission
Tomography
 Uses tracer (radioactive isotope that
identifies cancer cells and follows their
course in the body)
 Tracer is injected into vein
 Scanner converts signal into an image
 Images are in color and the degree of
metabolism or blood flow in indicated
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Patient Preparation
 Patient must fast for 6 hours before PET
scan
 Patient is seated in reclining chair to
receive IV injection
 After 45 minutes, the patient lies on the
scanner table for up to 2 hours
 The body excretes the medication in a
few days
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Radiation Safety
 Follow safety
procedures to
prevent exposure to
radiation
 Dosimeter (film
badge) measures
quantity of radiation
 Dosimeters are
evaluated
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Scheduling Diagnostic
Imaging Procedures
 Pretest instructions are important
 Medical assistant should explain
instructions and answer questions
 Give written instructions with
appointment card, date and time of
test, and directions to hospital or
imaging center
 Call to remind patient of appointment
24 hours prior to scheduled procedure
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Discussion
 Explain differences between ultrasound,
MRI, CT, X-ray, and PET
 Demonstrate X-ray positioning and
have classmates identify position
 List preparation for mammography
 Define contrast medium and identify
tests that use it
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Credits
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