dasar ultrasound

7/28/2019 Dasar Ultrasound

1/81

Introduction to Ultrasound

Scanning


2/81


3/81

Diagnostic Ultrasound

Disadvantages- Use is limited in the evaluation of dense

structures, air filled structures or thegastrointestinal tract

- Doesnt provide any information aboutorgan function

- Can not distinguish between benign andmalignant tissue


4/81

Information Provided from

Ultrasound Ultrasound provides information

concerning size, shape, echo pattern and

position of organs and other structures-The ultrasound professional must know the normalpatterns of all organs, including shape, contour,texture, internal architecture, and relative position

-Any disruption of normal patterns suggests an anomalyor abnormality


5/81

Essentials for a good

sonographic examClinical considerations include:

Patient positions for specific examsTransducer selection

Scanning techniques

Patient breathing techniques

These are the things you will learn in this class!!!


6/81

Labeling Sonographic Images

Ultrasound images are labeled as transverseor

longitudinalfor specific organs (ex: Long. Liver)

Patient position should be included (ex: Rt. Decub)

**Labeling protocols will vary slightly from office to office**


7/81

Scan Planes

2 basic scan planes are used in abdominalultrasound scanning. Sagittal / LongitudinalPatients body/organ

is divided in into unequal right and left halves TransversePatients body/organ is divided

into unequal top and bottom halves


8/81

Longitudinal/Sagittal Scan Plane

Transducer placement for longitudinal scan

plane


9/81

Long./Sagittal Monitor Correlation

In the longitudinal scan plane with patient supine:

the top of the U/S monitor corresponds to theanterior anatomy of the patient

the bottom of the U/S monitor corresponds to theposterior anatomy of the patient

the left side of the screen corresponds to theanatomy closest to the patients head

the right side of the screen corresponds to theanatomy closest to the patients feet


10/81

Transverse Scan Plane

Transducer position forthe transverse scan

plane


11/81

Transverse Monitor Correlation

In the transverse scan plane with thepatient supine:

The top of the U/S monitorcorresponds to the anterioranatomy of the patient

The bottom of the U/S monitorcorresponds to the posterioranatomy of the patient

The left side of the U/S monitorcorresponds to the patients rightside

The right side of the U/S monitorcorresponds to the patients left

side


12/81

Prone Patient

At times it is necessary to image a patient prone


13/81

Prone Patient Monitor Correlation In the longitudinal plane with the patient prone:

The top of the U/S monitor corresponds to the posterior anatomy of thepatient

The bottom of the U/S monitor corresponds to the anterior anatomy ofthe patient

The left side of the screen corresponds to anatomy closest to thepatients head

The right side of the screen corresponds to the anatomy closest to thepatients feet

Note: The only thing that

changes when imaging

in the longitudinal plane

when the patient is prone

is the anteriorand

posterioranatomy (top

and bottom of the

screen)


14/81

Prone Patient Monitor Correlation

In the transverse plane with the patientprone:

The top of the U/S monitor correlates with theposterior anatomy of the patient

The bottom of the U/S monitor correlates withthe anterior anatomy of the patient

The right side of the screen correlates withthe anatomy on the patients right side

The left side of the screen correlates with theanatomy on the patients left side


15/81

Sonographic Definitions

Echoes are the bright spots that make upan ultrasound image.

Echoes are the reflections of the sound beam

Echoes represent the anatomy beingevaluated with ultrasound

Echoes vary in brightness giving valuableinformation about the organ


16/81


If a structure has a lot of echoes within it,it is called echogenic/hyperechoic

Echogenic/hyperechoic an echoproducing structure; reflects sound

with a brighter intensity


17/81


Structures/organs that contain echoes that areexaggerated and extremely bright are referred to

as hyperechoic

This usually suggests a very solid or densestructure or echo enhancement resulting from

the sound beam passing through a fluid


18/81


The liver can bedescribed as

hyperechoic ormoderately echogenic

liver

RtKid


19/81


Hyperechoic liver lesion


20/81


Hyperechoic area posterior to gallbladder


21/81


Hypoechoic Low level echoes within a

structure


22/81


Hypoechoic liver lesion


23/81


Hypoechoic renal cyst


24/81


The terms hypoechoic and hyperechoicare also used to compare different organs

echogenicities. If one organ appears brighter or contains

more echoes than another organ then thatorgan is said to be hyperechoic or moreechogenic than the other


25/81


In this image, the livercan be described asbeing hyperechoic to the

Rt. Kidney or moreechogenic than the Rt.Kidney

The liver contains more

and brighter echoesthan the kidney


26/81


The terms hypoechoic and hyperechoicare also used to compare different organs

echogenicities. If one organ appears less bright or contains

fewer echoes than another organ that organis said to be less echogenic or hypoechoic tothe other organ.


27/81

Sonographic Definitions In this image the liver can be described as being

hypoechoic to the pancreas or less echogenic than thepancreas

Liver

panc


28/81

Sonographic Definitiosn

The term anechoic/sonolucent (withoutechoes) is used to describe anatomy or

structures that contain no echoesAnechoic structures are represented on

ultrasound as black

Usually an anechoic structure is a fluid filledstructure


29/81

Sonographic Terms

The normal gallbladder is an anechoic organ


30/81


Normal anechoicurinary bladder


31/81

Sonographic Definitions Anechoic renal cyst


32/81


Two structures that have the sameechogenicity are referred to as beingisoechoic to each other

Isoechoic is also used to describe anorgan when normal parenchymalechogenicity pattern exists


33/81


In this image the liverand the lymph nodes

present are isoechoicor isosonic


34/81


This liver can bedescribed as being

isoechoic since itexhibits a normal liver

echo pattern


35/81


The terms homogeneous andinhomogeneous/heterogeneous are usedto describe the texture of the anatomy

being evaluated with ultrasound Homogeneous describes smooth uniform

texture throughout a structure

Normal structures without pathology presentwill have a homogeneous texture


36/81


The normal liver should appear homogeneous


37/81


Heterogeneous / Inhomogeneousdescribes texture that is not uniform or

smooth throughoutAn organ or anatomy with a heterogeneous

texture would indicate pathology orabnormality


38/81


This diseased liver would be described as

inhomogeneous or heterogeneous


39/81


Once you become familiar with normalanatomy you will easily be able to spot

abnormalities

You may not know immediately what thespecific pathology is, but you will knowthat something is wrong!

Your mission in this class is to get to knownormal sonographic anatomy!!!


40/81

Introduction to Scanning

Transducer Formats:

The format of an image is determined by thetype of transducer being used

There are three primary image shapes:

Sector

Linear Array

Curved Linear


41/81

Introduction to Scanning Sector

Displayed as a pie shaped wedge.

Advantage : the sector transducerhas a smaller face, or footprint,

which allows for scanning in small ortight spaces (i.e. between ribs orunder xiphoid)

Disadvantage : skin contact area is

small and the image produced has alimited field of view of structuresnear the skin surface


42/81


Image produced witha sector transducer


43/81


Linear Array

Rectangular format

Advantage : allows for imaging awider field of view

Disadvantage : large footprint noteasily used in small areas


44/81


Image produced with a lineararray transducer


45/81


Curved Linear Array

Also referred to as Convex Array

Displayed as a blunted pie shaped wedge

The curved linear array is a good compromisebetween the sector and linear transducers

The footprint is smaller than the linear transducerand the curve allows for better contact in small

spaces It still allows for a wider field of imaging


46/81


Curved Linear Array

Also referred to asConvex Array


47/81


Image produced with acurved linear array

transducer


48/81

Introduction to ScanningAcoustic Window

Any medium or structure which transmits soundwell

During an upper abdomen ultrasound exam the livermakes and excellent window for imaging the otherabdominal structures

The sonographer can take several images by simply

sweeping the sound through the window, changingonly the tilt or angle of the transducer


49/81


Transducer Manipulation

Sliding

Rocking Tilting

Rotating

Compression


50/81


Sliding refers to grossmovement of the transducerfrom one location to another

and can be from or to anydirection


51/81


Rocking the transducer towards a point ofreference or away from it enables thesonographer to center the point on

interest or extend the field of view in onedirection or another.

Also called In-plane motion because it

allows for visualization of more anatomy inthe original plane slice


52/81


Rocking


53/81


Illustration showing the change in the soundbeam along the same plane when rocking


54/81

Introduction to Scanning Tilting involves angling the transducer from side to

side

Also called cross-plane motion because it allows for

visualization in other planes in the same axis


55/81


Illustration showing thechange in planes of the

sound beam when tilting


56/81

Artifacts

In most imaging fields artifacts usuallydegrade an image and are considered

undesirable.

In ultrasound artifacts can be useful in

identifying anatomy and pathology.


57/81


58/81


59/81

Artifacts

Posterior enhancement

seen behind the twocysts located in the

testicle


60/81

Artifacts Shadowing opposite of posterior

enhancement. Area behind the structureis hypoechoic or may even be anechoic.

Produced when the sound beam iscompletely reflected or absorbed by thestructure being imaged.

Usually indicates a solid structure.


61/81

Artifacts

Shadow producedby gallstones


62/81


63/81

Artifacts

Gas or air-filled structures can reflectsounds and produce shadows.

Shadowing produced by an air-filledstructure is described as a dirty shadow.

The shadow behind a stone or a rib

is sharply defined or described as a cleanshadow.


64/81

Artifacts

Dirty shadow produced by air in bowel


65/81

Artifacts

Refraction Shadowing resulting frombending of the sound beam.

If an echo is not received by thetransducer because of refraction, it isnot displayed on the image.

This often occurs at the edge of cysts. This is also referred to as edge shadowing


66/81


67/81

Artifacts

Reverberation result due to the soundsignal bouncing off a strong reflectiveinterface.

Frequently seen when a fluid-filled structureis in close proximity to the transducer(anterior region of the bladder during a

pelvic scan)

Appear as soft specular echoes in theanterior portion of the fluid structure.


68/81

Artifacts

Reverberation seen

anterior bladder


69/81


70/81

Artifacts

Ring down artifact seen in this transverseview of the thyroid. It occurs due to the air

within the trachea.


71/81

Artifacts

Mirror artifact Occurs when the soundbeam hits a curved structure, which

focuses the sound beam like a mirror.

A mirror image is seen immediately behindthe original reflector.

Occurs frequently when scanning thediaphragm.


72/81

Artifacts

Mirror image artifact

due to the diaphragm

There appears to beliver tissue in the lungs


73/81

Artifacts

Mirror image artifactdue to the diaphragm

The liver cyst isduplicated superior

to diaphragm


74/81

Artifacts

Mirror image artifactdue to the bladder wall

The bladder tumor and partof the bladder is duplicatedoutside of the bladder wall


75/81

Artifacts

Mirror image artifactdue to the bladder wall

The bladder is duplicatedoutside of the bladder wall


76/81

Artifacts

Propogation Velocity Artifact Causes amisregistration of information resultingfrom the change in sound velocity as itpasses through different densities.

If the sound is delayed, it is recorded

as being positioned deeper than it actuallyis.


77/81

Artifacts

Propogation velocityartifact causes this

diaphragm to lookfractured

The sound travels slower through the livertumor so the echoes posterior to the tumorare misplaced to appear deeper than they

actually are


78/81


79/81

Artifacts

Movement artifactseen due to patient

inspiration andexpiration

The diaphragm is distorted


80/81

Assignments

There will be a quiz over todays materialnext Wednesday

Read Chapter 5 on the Vascular System.Pg 101-122


81/81

References

Textbook of Diagnostic Ultrasonogaphy 6thedition Hagen-Ansert

dasar ultrasound

Documents