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29 Cards in this Set
- Front
- Back
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What is an ultasound?
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Ultrasound:
High Frequency Sound Waves > 20,000 Cycles/Second |
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What does frequency mean?
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Number of Wave that cross a given point in one second, expressed as Hertz (Hz).
Most Machines: 2-10 Million Hz (2-10 MHz) |
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How does image quality relate to frequency?
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Image Quality:
Improved at Higher Frequencies However, Depth Penetration is Reduced |
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What is the average frequency for transvaginal versus abdominal transudcers?
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Image Quality:
Improved at Higher Frequencies However, Depth Penetration is Reduced Abdominal Transducers: Operate at 3.5 to 5 MHz, lower frequency, higher penetration Transvaginal Transducers: Operate at 5 to 7.5 MHz |
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What are the different modes of the transducer and what are they used for?
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M (Motion) Mode:
Useful for Fetal Echocardiography B (Brightness) Mode: Generates Real Time Images 3 and 4 dimensional ultrasound Doppler Mode: Vascular Studies Cord Studies Power Mode: Like Doppler Does Not Discriminate Direction |
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What are the different ultrasound types?
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First trimester Ultrasound
Basic ultrasound Targeted Ultrasound Limited Ultrasound |
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What is noted in a first trimester ultrasound?
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Site of gestational sac
No of gestational sac No of fetuses Yolk sac, Amniotic fluid assessment Placenta location Size & position of uterus Uterine abnormalities Measurement of the cervix Evaluation of both adnexa Embryo Crown rump length Fetal cardiac activity Fetal movements Nuchal translucency |
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What is the targated ultrasound and when should it be included?
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The targeted ultrasound includes the basic ultrasound plus a fetal anatomical scan.
A targeted ultrasound should be included in the initial ultrasound done after 14 weeks. |
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What are the indications of a limited ultrasound?
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INDICATIONS include:
Assessment of amniotic fluid volume Fetal biophysical profile testing Ultrasonography- guided amniocentesis Confirmation of fetal life or death Localization of placenta in antepartum hemorrhage Confirmation of fetal presentation |
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When is serial ultrasound used?
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To rule out hydrops
Hydroneprosis Post urethral valves Ureteroceles Pleural effusion Congenital diaphrgamatic hernia CCAM Omphalocele Gastroschisis Dilated bowel hydrocephaly Cardiac defects ovarian cysts Twin twin transfusion syndrome |
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What are the causes of hydrops?
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HYDROPS:
ISOIMMUNIZATION PARVO VIRUS CYTOMEGALOVIRUS TOXOPLASMOSIS CYSTIC HYGROMA SACROCOCCYGEAL TUMOR |
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What can targated ultrasound be used to visualize?
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Cerebral ventricles
Posterior Fossa Face 4 chambered heart Outflow tracts Chest Spine Stomach Trivascular cord Cord insertion Kidneys Bladder Upper extremeties Lower extremeties Gender Doppler studies |
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What is the accuracy of gestational age indicators of ultrasound and physical exam?
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First trimester physical examination + 2 weeks
Second trimester physical examination + 4 weeks Third trimester physical examination + 6 weeks First trimester ultrasound + 5-7 days Second trimester ultrasound + 10-14 days Third trimester ultrasound + 17-21 days |
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What happens in anecephaly? what is missing? What causes anecephaly?
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Defect in anterior neural tube closure resulting in cranial vault absence
Absence of forebrain, meninges, skull, skin Folic acid antagonist Valproic acid Hyperthermia Diabetes Polyhydramnios Elevated MSAFP |
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How is ventriculomegaly defined and what causes it?
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Dilated Ventricles: atrium >10mm
Aqueductal Stenosis Communicating hydrocephaly Dandy-Walker syndrome Arnold-Chari malformation with NTD, Tumors, hemorrhage, X-linked aqueductal stenosis Infection |
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What are the inheritance trates of Dandy-Walker Syndrome? What is missing?
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Chromosomal anomalies 15-30%
Congenital infection Mendelian syndrome 35% postnatal mortality I/3 of survivors have IQ > 80 A posterior fossa cyst A defect in the cerebellar vermis Communication between cyst and 4th ventricle Hydrocephaly Dandy Walker syndrome: absent vermis, enlarged posterior fossa, dilated 4th ventricle |
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What is the inheritance of holoprosencephaly? What are the causes? And What are the symptoms?
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Trisomy 13, 18,
Mendelian inheritance Diabetes Alcohol Retnoic acid, Infections LETHAL Forebrain cleavage abnormalities resulting in fusion of cerebral hemispheres Fused thalami SINGLE VENTRICLE Facial defects (Cyclops/ proboscis Median cleft lip) |
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What is encephalocele? What are the causes? and what are the symptoms?
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Neural tube defect resulting in a mid-line mass overlying a skull defect
Meckel-Gruber syndrome Cocaine, Rubella, hyperthermia Prognosis dependent on associated malformations & amount of brain tissue involved |
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What is intraventricular hemmorage?
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Clot in frontal horn, dilated 3rd ventricle
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What are the cranial abnormalities found in spina bifida?
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Overlapping coronal bones termed lemon sign
Compressed cerebellum termed Banana sign |
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What can be seen in a normal transverse section of the spine?
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3 ossification centers arranged in a circle
Transverse scan shows spinal structures surrounding spinal cord |
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What is the definition of hydrops?
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Fluid collection in two or more body cavities, including:
Skin edema Pleural space (effusion) Pericardial space (effusion) Abomen (ascites) Polyhydramnios Placental edema |
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what is a congenital diaphragmatic hernia?
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Protusion of abdominal contents into the chest cavity through diaphragmatic defects resulting from a failure of closure.
Posterolateral =Foramen of Bochdalek Retrosternal= Foramen of Morgagni Left sided= stomach Right sided= Liver( worse prognosis) Mortality due to pulmonary hypoplasia |
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What are congenital cystadenomotid malformations?
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Commonest pulmonary congenital defect
Hamartoma or focal dysplasia of lungs Due to failure of normal lung to develop Type 1- macrocystic = cysts 2-10 cm Type II- medium-size cysts Type III- microcystic =cysts 0.3-.0.5 cm Pulmonary hypoplasia or hydrops may occur |
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What are the signs of bowel obstruction?
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Double Bubble Sign, Dilated Loops of Bowel, Duodenal atresia
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What is gastroschisis?
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Evisceration of fetal intestine through a paramedian wall defect
Usually isolated Elevated MSAFP Intestinal obstruction/atresia Stillbirths >90% newborn survival with surgery |
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What is an omphalocele?
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Herniation of abdominal viscera into umbilical ring
Associated anomaly in 50% Elevated MSAFP Viscera is covered by a membrane 80% contain liver |
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What are urinary tract defects?
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Obstructive Uropathy with normal bladder
UPJ obstruction Obstructive Uropathy with large bladder Posterior urethral valves Lethal Urinary Tract Defects Infantile polycystic kidney disease Bilateral Multicystic kidneys Bilateral Renal Agenesis |
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What is hydronephrosis?
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Distension of pelvis & calyces with urine
Ureteropelvic junction obstruction is common cause Vesicoureteric reflux is common |
