Transcript File - BINZHOU MEDICAL UNIVERSITY

Foundations
of Sonography (2)
Chuan Lu 卢 川
Department of
Diagnostic Medical Imaging
School of Radiology
Taishan Medical University
Topics
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Introduction to Scanning Techniques
Orientation to Labeling and Patient Position
Sonographic Terminology
Ultrasound Criteria For Cyst/Complex/Solid
Patient Preparation
Clinical Applications of Ultrasound
Introduction
to Scanning Techniques
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The state of the art ultrasound demands a
high degree of manual dexterity and handeye-coordination and ability to conceptualize
two-dimensional information into a three –
dimensional format.
In addition, the sonographer must possess a
thorough understanding of anatomy ,
physiology, instrumentation, artifact
production, and transducer characteristics.
Sectional Anatomy
The sonographer must have a solid knowledge
of both gross anatomy and sectional anatomy ,
and the normal anatomical variations that may
occur in the body.
The sonographer should carefully evaluate
organ and vascular relationships to the
neighboring structures rather than memorizing
where in the abdomen a particular structure”
should “ be ( i.e., it is better to recall the location
of the gallbladder as anterior to the right kidney
and medial to the liver than to remember it is
found 6 cm above the umbilicus)
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Ultrasound equipment today is so
sophisticated that it demands a much greater
understanding of the physical principles of
sonography to produce quality images.
The addition of Doppler techniques , color
flow mapping, and three-dimensional imaging
has enhanced the understanding of anatomy
and physiology as it relates to blood-flow
dynamics and reconstruction
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The student will soon learn that the “art of
scanning” cannot be acquired from reading a
textbook; the one-on-one, individual “hand –on”
training in a clinical atmosphere is a critical and
integral part of the sonographer’s experience in
producing high-quality scans.
The sonographer must be aware of the special
scanning techniques , artifacts encountered , and
equipment malfunctions to be able to produce
consistently high-quality scans .
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Ultrasound can distinguish interfaces among
soft tissue structures of different acoustic
densities . The strength of the echoes
reflected depends on the acoustic interface
and the angle at which the sound beam
strikes the interface.
The sonographer must determine
which ”window “ on the patient is the best to
record optimal ultrasound images and which
transducer will best fit into that window.
Orientation
to Labeling and Patient Position
Terms Relating to Orientation
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Anterior or Ventral : Structure lying toward
the front of the patient
Posterior or Dorsal: Structure lying toward
the back of the patient
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Lateral : Structure lying away from the
midline
Medical :Structure lying toward the midline
Proximal :Near
Distal : Away from the origin
Prone : The patient lies on his or her
stomach
Supine: The patient lies on his or her back
Terms Relating to Orientation
Proximal :Near
Anterior or Ventral : Structure lying
toward the front of the patient
Superior ,Cranial ,Cephalad
:Interchangeable terms
denoting a structure closer to
the patient’s head
Inferior or Caudal :
Terms denoting a
structure closer to the
patient’s feet
Distal : Away from the origin
Posterior or Dorsal: Structure lying
toward the back of the patient
Terms Relating to Labeling
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The American Institute of Ultrasound in
Medicine( AIUM) has established standards
for labeling studies so that a sonogram done
in Columbus , Ohio, can be interpreted with
no misunderstanding in Baltimore, Maryland.
These standards are occasionally revised
and are available on request from the ( AIUM)
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One of the great features of real-time
ultrasound is that structures can be visualized
in their long axis, which may be oblique and
not fall neatly into a sagittal or transverse
plane
However, the basic principle of examining
everything in at least two plane is a sound
one, so suggestions for labeling an abdomen
in longitudinal and transverse plane will be
discussed here
Longitudinal (Sagittal )Scans
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In the abdomen, the aorta and the inferior
vena cava(IVC) may not follow an exact
longitudinal plane, but should be imaged in
their long axis if possible . Since these
images also include other anatomy of
interest-left lobe of liver, superior mesenteric
artery, pancreas, and so forth-it suffices to
label them ”ML” (midline) unless you wish to
draw the sonologist’s attention to something
in particular.
Longitudinal scans present the patient’s
head to the left of the screen and feet to
the right of the screen and use the
xiphoid , umbilicus , or symphysis to
denote the midline of the scan plane.
longitudinal scans (Sagital Scan)
The longitudinal scans for the abdomen and pelvis are oriented
with the patient’s head toward the left of the screen and feet
toward the right of the screen. This means the sonographer would
be viewing the body from the right side of the patient.
Longitudinal scan
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The longitudinal scans for the abdomen and pelvis are
oriented with the patient’s head toward the left of the screen
and feet toward the right of the screen.
The longitudinal scans for the abdomen and pelvis
are oriented with the patient’s head toward the left of
the screen and feet toward the right of the screen.
This means the sonographer would be viewing the
body from the right side of the patient.
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Ultrasound of spleen and left kidney—Patient lying on back head to left.
a. spleen
b. left kidney
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All transverse supine scans are oriented
with the liver on the left of the screen ;this
means the sonographer would be viewing
the body from the feet up to the head
(“optimistic view”)
Transverse Scan
All transverse supine scans are oriented as looking
up from the feet, with the liver on the left side of the
screen( right side of the patient is on the left of the
screen)
Transverse Scan
All transverse supine scans are oriented as looking up from
the feet, with the liver on the left side of the screen( right
side of the patient is on the left side of the screen)
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Normal pancreas seen on sonogram. Looking up from
abdomen toward the head of the patient. The liver is in
front of the pancreas. A vein draining the spleen is
behind the pancreas.
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Transverse Scans
Transversely ,whether you are angling
cephalad or not, on inspiration or not ,”trans
left,” ”trans right,””trans left obl,” “trans right
obl” will cover most of the labeling needed in
the abdomen.
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All scans should be appropriately labeled for future reference.
This include the patient’s name, date, and anatomic position.
Body position markers are available on many ultrasound
machines and may be used in the place of written labels
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Decubitus
These are scans taken with the patient lying
on either side; following the traditional
radiology standard, the label is for the side
down. So an image of the left kidney , taken
with the patient on her right side, is labeled
“right lateral decubitus.”
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The position of the patient should be
described in relation to the scanning
table( e.g., a right decubitus would mean the
right side down; a left deculitus would
indicate the left side down).
If the scanning plane is oblique ,the
sonographer should merely state that it is an
oblique view without specifying the exact
degree of obliquity
Oblique Scan
Coronary scan
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Real-time scans are labeled as transverse
or longitudinal for a specific organ, such as
the liver , gallbladder, pancreas , spleen ,
or uterus.
The smaller organs that can be imaged on
a single plane, such as the kidney , are
labeled as long-middle, -lateral ,or medial ;
whereas the transverse scans are labeled
as transverse –low,-middle , and high.
Sonographic Terminology
Sonographic Terminology
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One of the primary responsibilities of the
sonagrapher is the identification and
description of normal and abnormal anatomy.
The following descriptive list of key
terminology will help the sonagrapher
summarize the results obstained from the
Ultrasound examination
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Anechoic or sonolucent-(black on screen )
(opposite of echogenic) well-defined
echgenic walls without internal echoes;
this structure is fluid-filled and transmits
sound easily
Anechoic or sonolucent (black-water):
Example: vascular structure (blood),
distended urinary bladder,
gallbladder (bile),
amniotic cavity,
simple cyst
Anechoic or sonolucent:
Example: vascular structure,
distended urinary bladder,
gallbladder,
amniotic cavity,
simple cyst
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Ultrasound of the gallbladder. The wall or lining of
the gallbladder is white, the bile within the
gallbladder is mostly made of water and it appears
as a clear black space within the walls of the
gallbladder.
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Echogenic or hyperechoic-(opposite of
anechoic) echo-producing structure:
reflects sound with a brighter intensity
Example: gallstone, renal calyx, bone, fat,
fissures, ligaments
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Hypoechoic: low –level echoes within a
structure
Example: liver, renal parenchyma, spleen,
pancreas, lymph nodes
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Hypoechoic: low –level echoes within a
structure
Example: liver, renal parenchyma, spleen,
pancreas, lymph nodes
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Isechoic- very close to the normal
parenchyma echogenicity pattern
Example: metastatic disease
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Enhancement, increased through
transmission-sound that travels through an
anechoic (fluid-filled) substance and is not
attenuated
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Homogenerous(opposite of heterogenerous) completely
uinform in texture or composition
Example: the text of the liver, thyroid,
scrotum, and myometrium are
homogenerous
Homogenerous
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Example: the texture of the liver, thyroid, scrotum,
and myometrium are homogenerous
Homogenerous
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Ultrasound of the liver. This image demonstrates
the (homogenerous.) liver tissue
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Inhomogenerous( hysterogeneous)-not
uniform in texture or composition
Example: many tumors have characteristics
of both” cystic” and solid types of patterns
Inhomogenerous( hysterogeneous)-not
uniform in texture or composition
Example: many tumors have characteristics
of both” cystic” and solid types of patterns
Inhomogenerous( hysterogeneous)-not uniform
in texture or composition
Example: many tumors have characteristics of
both” cystic” and solid types of patterns
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homegenous
Inhomegenous
Acoustic Shadowing
Shadowing-the sound beam is attenuated
by a solid or calcified object.
 This reflection or absorption may be partial or
complete .
 A stone would cause a sharp shadow
posterior to its border
 Air bubbles in the duodenum may cause a
“dirty shadow” to occur secondary to
reflection.
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Acoustic Shadowing
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A stone would cause a sharp shadow
posterior to its border
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Fluid level-interface between fluids with
different acoustic characteristics. This level
will change with patient position
Example: dermoid with fluid level
Ultrasound Criteria
For Cyst/Complex/Solid
Ultrasound Criteria For
Cyst/Solid/Complex
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The through transmission of the sound is either
increased, unchanged ,or decreased .An anechoic
mass will show increased transmission of
sound ,whereas a dermoid tumor will show
decreased transmission
The characteristic of an organ or mass is said to be
either anechoic , hypoechoic, isoechoic ,
hyperechoic ,or echogenic
Transmission is altered by whether a structure is
cyst, complex ,or solid
Ultrasound Criteria For Cyst/Solid/Complex
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Cyst : Anechoic, smooth, well-defined border,
increased transmission
Solid : Internal echoes , irregular /regular
borders , decreased transmission
Complex: Has characteristics of both cyst
and solid
Cyst :
Anechoic, smooth, well-defined border,
increased transmission
Cyst :
Anechoic, smooth, well-defined border,
increased transmission
Solid : Internal echoes , irregular /regular
borders , decreased transmission
Solid : Internal echoes , irregular
/regular borders , decreased
transmission
Solid : Internal echoes , irregular /regular
borders , decreased transmission
Solid : Internal echoes , irregular
/regular borders , decreased
transmission
Complex: Has characteristics of both
cyst and solid
Complex:
Has characteristics of both cyst and solid
Complex:
Has characteristics of both cyst and solid
Ultrasound Criteria For
Cyst/Complex/Solid
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After the sonographer has delineated the
normal landmarks and anatomic structures,
careful evaluation is made for the presence of
pathology. The abnormality is evaluatated by
several criteria which include:
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The border of the structure may be smooth and
well-defined, or irregular
The texture(or parenchyma) of the structure is
either homogeneous or heterogeneous;if a mass is
present, it may be hypoechoic, echogenic, or
isoechoic to the rest of the parenchyma
The through transmission of the sound is either
increased , unchanged, or decreased, whereas a
dermoid tumor will show decreased transmission
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The characteristic of an organ or mass is
said to be either anechoic, hypoechoic,
isechoic, hyperechoic, or echogenic
Transmission is altered by whether a
structure is a cyst, complex, or solid
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Cyst: Smooth ,well-defined borders, anechoic,
increased transmission
Complex: Has characteristics of both cyst
and solid(abscess)
Solid:Irregular borders, internal echoes,
decreased transmission
Patient Preparation
Patient Preparation
Gallbladder and Pancreas Scans
 Patients scheduled for upper abdominal scans
should ingest nothing that will make the gallbladder
contract for at least 8 hours preceding the sonogram.
 Water is acceptable, but often the patient is
scheduled for an upper gastrointestinal series the
same day.
 This can be a problem if good visualization of the
pancreas is required , since water in the stomach is
often crucial to the ultrasound exam. In those cases
requiring the ingestion of water , the GI series
should be scheduled for the following day.
Patient Preparation
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Pelvic Scans
The bladder should be distended to provide an
acoustic window to the pelvic structure in patient
undergoing a transabdominal pelvic scan.
Outpatients should be instructed to drink enough
fluid –at least 16 ounces –to make their bladder
slightly uncomfortable at the time of exam.
Since an endovaginal examination is very often
used as a follow-up, we now recommended not
emptying the bladder 2 hours before an exam rather
than drinking water if a transvaginal exam is likely
to be performed .
Obstetric Scans
 For early transabdominal obstetric scans, the
bladder should be distended enough to
visualize the lower uterine segments .
 After 20 weeks , the bladder should be empty
to evaluate properly the cervix and
relationship to the placenta
Clinical Applications of Ultrasound
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Abdominal ultrasound
Gynecology
Obstetrics
Echocardiography
Small parts: thyroid, breast, Scrotum.
Vessels
Musculoskeletal ultrasound
Clinical Applications of Ultrasound
Abdominal ultrasound
 Digestive System:
The Liver, Gallbladder, Biliary System,
Pancreas, Spleen
 Urinary System:
Kidney, Bladder,Prostate
Clinical Applications of Ultrasound
Gynecology
 Infertility: For Ovulation Induction
 Intrauterine Conceptive Device
 Uterine anomalies
 Ovarian anomalies
 Rule out Pelvic Mass:
Ovarian masses (cystic , solid, complex)
Uterine Masses
Clinical Applications of Ultrasound
Obstetrics
 First Trimester Pregnancy
 Second and Third Semesters Pregnancy
 Obstetric Measurement and Gestational Age
 Fetal Growth Assessment
 Prenatal Diagnosis of Congenital Anomolies
 Fetal Well-Being and Fetal Death
Clinical Applications of Ultrasound
Vessels
 Extracranial Cerebrovascular Evaluation
 Intracranial Cerebrovascular Evaluation
 Peripheral Arterial Evaluation
 Peripheral Venous Evaluation
Thank You