Chapter 21: Ultrasonography Flashcards
What are the types of US?
A-mode B-mode M-mode Doppler Duplex US
What is an A-mode US?
The simplest
Spikes along a line represent the signal amplitude at a certain depth
Used mainly in ophthalmology
What is a B-mode US?
Mode most often used in diagnostic imaging
Each echo is depicted as a dot, and teh sonogram is made up of thousands of these dots
Can depict real time motion
What is M-mode US?
Used to show moving structures such as blood flow or motion of the heart valves
What is a Doppler US?
Uses the Doppler effect to assess blood flow
Used for vascular US
Pulsed Doppler devices emit short bursts of energy that allow for an accurate localization of the echo source
What is a duplex ultrasonography?
Used in vascular studies
Refers to the simultaneous use of both grayscale or color Doppler to visualize the structure of and flow within a vessel and spectral Doppler to quantitate flow
What are the advantages of US?
No ionizing radiation
No known long term side effects
“Real time” images
Produces little to no patient discomfort
Small, portable, inexpensive, and ubiquitous
What are the disadvantages of US?
Difficulty penetrating through bone
Gas-filled Structures reduce its utility
Penetration may be difficult in obese patients
Dependent on the skills of the operator doing the scanning
What are the uses of US for pregnancy?
Fetal presence and gestational age Fetal abnormalities and viability The presence of multiple pregnancies Placental localization Amniotic fluid volume Intrauterine growth retardation Helping to guide invasive studies such as amniocentesis, chorionic villus sampling, and intrauterine transfusions
What are CNS abnormalities diagnosable using US?
Hydrocephalus Abnormalities of prosencephalon A genesis of the corpus callous Intrauterine infections Cysts Meningomyelocele Anencephaly
What skeletal abnormalities can be diagnosed on US?
Dwarfism Skeletal dysphasia Achondroplasia Osteogenesis imperfecta Asphyxiating thoracic dysplasia Limb anomalies
What GI abnormalities can be diagnosed using US?
Esophageal atresia Tracheoesophageal fistula Duodenal atresia Small and large bowel obstruction Abdominal wall defects Congenital diaphragmatic hernias Choledochal cyst
What Genitourinary tract abnormalities can be diagnosed using US?
Renal agenesis Congenital ureteropelvic junction and ureterovesical junction obstruction Bladder outlet obstruction Multicystic dysplastic Kidney Poly cystic kidney disease
What cardiac anomalies can be diagnosed with US?
Hypoplastic left heart syndrome Tricuspid atresia Endocardium cushion defects Ebstein anomaly Tetralogy of Fallot Transposition of the great vessels Coarctation of the aorta Cardiac arrhythmias
What three components are there of a sonogram?
Production of a high frequency sound wave
Reception of a reflected wave or echo
Conversion of the echo into the actual image
