Download diagnostic ultrasonography

DIAGNOSTIC
ULTRASONOGRAPHY
CHAPTER 23
PRINCIPLES OF ULTRASOUND
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1)
2)
The use of sound waves beyond the
audible frequency ( > 20,000 Hz) for
diagnostic purposes.
Can be used for therapeutic purposes by
using larger and continuous dosages –
as in:
Generation of heat- treatment of low
back pain, muscle strains, promote
tissue regereration, kill malignant cells.
To pulverize kidney stones, gallstones.
PRINCIPLES OF ULTRASOUND
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Sound waves are generated by the
TRANSDUCER- the gizmo holding a
piezoelectric crystal that changes
electrical current into sound waves and
vice versa.
Sound waves are generated, reflected off
of tissues and “echo” back, and are
picked up by the transducer
(piezoelectric crystal) and converted to
electrical activity.
PRINCIPLES OF ULTRASOUND
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The image that is generated is
dependent upon the time it takes
the sound waves to return to the
transducer.
The return time is a reflection of the
distance the tissue is from the
transducer and the degree to which
the sound waves are reflected by
that tissue (organ vs. bone vs. fat
vs. fluid).
HAZARDS OF DIAGNOSTIC
ULTRASOUND
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In short, for diagnostic ultrasound,
there are none.
Ultrasound for longer periods of
time than are used in diagnostic
ultrasound can generate sufficient
heat as to be harmful.
And in higher frequencies
(>100,000 Hz) can cause
cavitation.
METHODS OF UULTRASOUND
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1) PULSE-ECHO
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2) DOPPLER
PULSE-ECHO METHOD
2 TYPES:
1)
2)
A MODE - amplitude modulation – echoes
are displayed in graphic form, such as in an
echocardiogram.
B MODE - brightness modulation – echoes
are displayed as different intensities of
brightness, giving a 2-dimensional crosssectional image (“picture”, if you will). Can be
static or dynamic (“real-time”).
DOPPLER METHOD
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Sound waves bounced off of different
objects have different frequencies.
With doppler ultrasound, these different
frequencies are transformed into audible
sounds, of different frequency.
The different frequencies can also be
mapped to give a visual representation as
well as an audible one.
DOPPLER METHOD
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USES
Flow through arteries and veins- to assess
patency of arterial grafts, obstruction to
flow by thrombi, atherosclerosis, etc.arterial flow can often be heard in cases
where it can not be palpated.
Opening and closing of cardiac valves
and flow through them- valvular stenosis,
regurg.
DOPPLER METHOD
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OBSTETRICAL USES
Doppler stethoscope- to detect a fetal
heart beat episodically, or continuously as
in labor.
Assessment of placental function / fetal
growth – evaluates flow through the
umbilical artery and vein, looks for
differentials in flow
DOPPLER METHOD
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COLOR FLOW IMAGING
A type of doppler study.
Asseses whether blood flow is laminar (the
usual way) or turbulent (the abnormal way).
Useful in: cardiac valvular regurgitation;
identification of a false lumen in aortic
dissection; congenital heart defects such as
patent ductus arteriosus, atrial and venticular
septal defects, which would appear as turbulent
flow.
DOPPLER METHOD
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DUPLEX SCANNING
Uses both real-time imaging and doppler
flow together.
Useful in evaluating a variety of vascular
problems: aneurysms, atheroscerotic
plaques.
APPLICATIONS OF ULTRASOUND
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CEREBRAL CIRCULATION
CAROTID ARTERY
GYNECOLOGIC / OBSTETRIC
TRANSVAGINAL / TRANSABDOMINAL
TRANSRECTAL / TRANSTHORACIC /
TRANSESOPHAGEAL
STRESS ECHOCARDIOGRAM
ECHOENCEPHALOGRAM
BREAST
BLADDER
CEREBRAL CIRCULATION
Measures blood flow in the cerebral
circulation, particularly in the:
1) Middle, anterior, and posterior cerebral
arteries.
2) Distal internal carotid.
3) Basilar artery.
 Often combined with doppler duplex
ultrasound and arteriography.
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CAROTID ARTERY SCANS
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Atherosclerosis is associated with
thickening of the intima of the artery.
Risk of cardiovascular disease and stroke
is proportional to the thickness of the
intima, which is a reflection of the degree
of atherosclerosis.
Useful for screening both symptomatic
patients who may need surgical
intervention and asymptomatic patients
who may need prevntive measures.
GYNECOLOGIC ULTRASOUND
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Uterus- size, shape (bicornuate),
presence of masses within (fibroids,
neoplasms).
Ovary- presence of masses, cysts,
neoplasms.
Tubes- hydrosalpinx, pyosalpinx in
PID, ectopic pregnancy.
RIGHT
OVARY
BENIGN CYSTIC TERATOMA
OBSTETRICAL ULTRASOUND
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Confirmation of intrauterine pregnancy,
presence of ectopic pregnancy, # of
fetuses.
Position of fetus(es), placenta (previa).
Guidance for amniocentesis.
Evaluation of fetal growth, gestational
age.
Evaluation of amniotic fluid volume.
Structural / congenital abnormalities of
the fetus.
ECTOPIC PREGNANCY
UTERUS:
SOLID MASS WITHIN
NO GESTATIONAL SAC
ECTOPIC PREGNANCY
ADNEXA:
CYSTIC MASS,
BETA HCG 17,000
COLOR DOPPLER (FLOW)STUDY
INCREASED
FLOW
ECTOPIC PREGNANCY
TWIN GESTATION
OB (FETAL) ULTRASOUND
26 WEEK FETUS:
CONGENITAL
POLYCYSTIC
KIDNEYS
23 YOF AT 20 WEEKS GESTATION
FETAL HYDROTHORAX (BILATERAL PLEURAL EFFUSIONS) AND
ASCITES, C/W HYDROPS FETALIS
23 YOF AT 20 WEEKS GESTATION
FETAL HYDROTHORAX (BILATERAL PLEURAL EFFUSIONS) AND
ASCITES, C/W HYDROPS FETALIS
OLIGOHYDRAMNIOS
OB SCAN - OMPHALOCOEL
OB SCAN - OMPHALOCOEL
PLAIN FILM - OMPHALOCOEL
TRANSVAGINAL ULTRASOUND
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Transducer placed in the vagina.
USEFUL FOR:
Evaluation of follicular development,
ovulation.
Ruling out ectopic pregnancy.
Evaluation of endometrial thickness – in
the assessment of post-menopausal
bleeding, need for biopsy.
Incompetent cervix.
BICORNUATE UTERUS
SAME BICORNUATE UTERUS
GESTATIONAL SAC
SAME BICORNUATE UTERUS
OTHER HORN
FLUID-FILLED
ONLY
TRANSVAGINAL SCAN
UTERUS:
COMPLEX, CYSTIC
MASS WITHIN THE
UTERUS
DDx
CYSTIC POLYP,
ENDOMETRIAL Ca,
ENDOMETRIAL
HYPERPLASIA
TRANSVAGINAL SCAN
On this image performed during sonohysterography,
two masses, one polypoid and another more broad-based,
extending from the endometrial lining are evident.
ULTRASOUND LEFT OVARY
HEMORRHAGIC CYST
SAME PATIENT
HEMORRHAGIC CYST RESOLVED
ABDOMINAL ULTRASOUND
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Often the 1st test used to evaluate
abdominal pathology (or 2nd, behind a
KUB).
Or complementary to other studies such
as radionuclide studies, CT, MRI, XRay/Contrast studies, etc. No radiation,
cheaper.
Needle-guided biopsies, paracentesis.
Examples: appendicitis, cholelithiasis,
aortic aneurysms, cysts / masses /
tumors / abscesses / ascites.
GALLBLADDER:
GALLSTONE,
WALL THICKENING
CHOLECYSTITIS
SAME PATIENT
COMMON BILE DUCT ENLARGED
ABDOMINAL SONOGRAM
A thickened gall bladder wall is noted, with some pericholecystic fluid
and shadowing echogenic foci likely representing stones
APPENDICITIS
TRANSRECTAL ULTRASOUND
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Primarily for evaluation of the prostatesize, shape, etc., to evaluate for BPH,
prostate cancer.
Used after evaluation by DRE (digital
rectal exam) and PSA (prostate-specific
antigen).
Used in needle-guided biopsies,
implantation of radioactive seeds for
treatment of malignancy of the prostate.
TRANSTHORACIC
ECHOCARDIOGAPHY
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USEFUL IN THE EVALUATION OF
Valvular defects, chamber size.
Structural abnormalities- patent ductus, atrial
and ventricular septal defects.
Pleural effusion, cardiac tamponade.
Color imaging can detect flow – laminar vs.
turbulent.
Some changes in coronary flow.
ECG sometimes done simultaneously.
TRANSESOPHAGEAL ULTRASOUND
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Generates an image unimpeded by the
lungs and chest-wall structures.
Especially good visualization of the left
atrium and aortic root.
Examples: infective endocarditis, aortic
dissection, cardiac origin of an arterial
embolus such as atrial fib. much better
than TTE.
RISKS: bleeding, aspiration, perforation,
arrhythmias.
ECHOENCEPHALOGRAM
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Ultrasound can not penetrate bone.
Limited use in the adult.
This modality is most useful for imaging
the newborn as the skull (sutures) have
not completely fused.
Useful for evaluating: mostly, things that
shift the midline, hydrocephalus, size of
the cerebral ventricles, intracranial
hemorrhage in the newborn.
ECHOENCEPHALOGRAM
“ANEURYSM” OF THE VEIN OF GALEN,
WHICH IS REALLY AN A-V FISTULA
SAME PATIENT - ANGIOGRAM
1 DAY OLD INFANT W/ HEART
FAILURE
1 DAY OLD INFANT W/ HEART
FAILURE
Head ultrasound shows a cystic mass, posterior to the
third ventricle. The mass is continuous with the dilated straight sinus.
1 DAY OLD INFANT W/ HEART
FAILURE
Doppler examination shows pulsatile high flow in the cystic mass.
THORACIC SONOGRAMS
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Limited utility due to the lack of
penetration of ultrasound by air.
Can detect pleural fluid, abscess,
malposition of the diaphragm.
ULTRASOUND OF THE BREAST
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Usually done adjunctively with or as a follow-up
to mammography.
Differentiates between solid and cystic lesions.
Helpful in women w/ dense breasts as glandular
tissue and malignancy both show up white on
mammogram. On ultrasound, malignancy
appears black.
Used to guide needle biopsy and to place a
surgical clip to mark the area for future
treatment.
MAMMOGRAM
PALPABLE MASS
BREAST ULTRASOUND
PALPABLE MASS,
CYSTIC ON
ULTRASOUND
BONE SONOGRAMS
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Primary use is as a screening tool
for osteoporosis, looking at the
heel, as healthy bone echoes sound
waves faster than does osteoporotic
bone.
Also used for congenital hip
dysplasia (dislocation).
BLADDER ULTRASOUND
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Used to determine volume of urine.
Main purpose is to determine urine
volume without having to
catheterize the bladder, avoiding the
risk of infection.
Image of the bladder is matched to
an image on the screen
corresponding to a pre-calculated
volume.
Compression U/S - LLE: Noncompressibility of common femoral vein with
echogenic thrombus within the vein lumen consistent with chronic DVT.
POLYCYSTIC KIDNEY DISEASE
18 YOM W/ TESTICULAR MASS
18 YOM W/ TESTICULAR MASS
EPIDERMOID CYST OF THE TESTICLE
ULTRASOUND-GUIDED NEEDLE
BIOPSY OF THE LIVER