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36 Cards in this Set
- Front
- Back
What is sonography?
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a noninvasive medical imaging technique that uses high frequency sound waves (ultrasound) to visualize internal body structures
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What is sonography used for?
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Diagnosis, Treatment planning, Biopsy, Operating Room for tumor localization
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What are the advantages of Sonography?
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noninvasive, no radiation, no iV injection, portable, painless, relatively inexpensive
most commonly used imaging technique in the world today |
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What are the disadvantages of sonography?
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operator dependence, bone/air/gas, obesity
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What two types of transducers are there?
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linear, with a rectangular screen and sector with a pie shaped screen
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What are the uses of the linear transducers?
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superficial structures: thyroid, parathyroid, breast, testes
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What are the uses of the sector transducers?
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deeper structures: liver, pancreas, uterus, ovary
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What are the frequencies of the transducer?
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2.25 MHz to 15 MHZ
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How does the frequency correspond to resolution?
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the higher the frequency the higher the resolution, the lower the frequency the lower the resolution
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How does frequency corespond to the depth of penetration?
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the higher the frequency the shallower the penetration, the lower the frequency the deeper the penetration
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What are the three types of anatomic scanning planes?
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sagittal- longitudinal (head L feet R)
transverse- coronal |
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What is sonography excellent for detecting?
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mass characterization: cyst (benign), solid (malignant), complex
detection of stones |
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how does one characterize a cyst?
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echo free center, smooth back wall, acoustic enhancement
(if have all three of these things, 93% cyst) |
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how does one characterize a solid mass?
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multiple echoes, back wall not smooth, no acoustic enhancement
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what are some examples of cystic masses?
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liver cyst, renal cyst
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What are some examples of solid masses?
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liver metastasis, renal cell carcinoma, seminoma
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How would a lymphoma characterize on an ultrasound?
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hypoechogenic, sheet of cells, not fibrous tissue, does not resolve thin walls,
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What are some examples of complex masses?
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hemorrhagic cyst, infected cyst, necrotic tumor, abscess
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What are some characteristics of a complex mass?
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features of both solid and cystic masses, 1/2 water
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how can the nature of a complex mass be characterized?
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determine how did it start off, was it a cyst or a mass
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What can happen to tumors to create a complex mass?
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tumor mass can undergo necrosis and create irregular borders
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What are the clinical indications for sonography?
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pregnancy/fetal evaluation, ovarian mass, RUQ/Urinary tract, Parathyroid Gland, Aneurysm/Carotid Artery, DVT-Other
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How can the transmission of sound waves be enhanced?
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improve contact with gel
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When and where does fertilization happen?
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Happens backwall of uterus, fundus, 6 days or a week before the patient misses their period
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When can an embryo be visulaized by sonography?
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when the embryo implants in the endometrium
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what in the intradecidual sign?
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when you can see the endometrial canal, 3 weeks after ovulation
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What is the double bleb sign?
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when you can see the heart beat, 6-7 weeks
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What is the prognosis for a fetal heart beat that is less than 100< ?
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The fetus is unlikely to survive
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What is the double sac sign?
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5-9 weeks/ pseudogestational sac of ectopic pregnancy
visualize a large balloon endometrial ccavity with a pseudogestational tract |
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What can happen at 11 week of pregnancy?
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crown rump length can be used to estimate aproximate gestational age and estimate the date of delivery
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Where are possible sites of ectopic pregnancies?
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abdomin, interstial, angular, tubal, ovarian
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What does an ectopic pregnancy look like on ultrasound?
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empty uterus and bagel donut sign
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What is anecephaly?
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neural tube defect, can diagnose at 14 weeks
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How do kidney stones visualize on ultrasound?
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acoustic shadow
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How do neuroendocrine tumors visualize on ultrasound?
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hypoechoic
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How do aneurysms visualize on ultrasound?
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get a abnormal dilation of an artery, color of blood flow changes
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