EDELMANS SPI EXAM QUESTIONS ANSWERED CORRECTLY LATEST UPDATE 2026

EDELMANS SPI EXAM QUESTIONS ANSWERED CORRECTLY LATEST UPDATE 2026 Depth of view increases - Answers PRF decreases Refraction if only two conditions are satisfied - Answers oblique incidence different propagation speeds of two media refraction - Answers change in direction of wave propagation when traveling from one medium to another transmission with a bend small diameter - Answers high frequency crystals higher frequency - Answers creates deeper focus deep focus - Answers -Larger diameter PZT -Higher frequency shallow focus - Answers -Smaller diameter PZT -Lower frequency focal depth and xducer diameter - Answers transducer diameter goes up focal depth goes up directly related focal zone - Answers half located in near zone half located in far field far zone - Answers -Far field -Fraunhofer zone starts at focus and extends deeper focal length - Answers focal depth near zone length distance from transducer to the focus transmitted intensity - Answers intensity of the portion of the incident beam that after striking a boundary continues forward reflected intensity - Answers the intensity of the proportion of the incident sound beam that after striking a boundary returns back incident intensity - Answers sound waves intensity immediately before it strikes a boundary near zone - Answers near zone fresnel zone region from the xducer to the focus oblique incidence - Answers occurs when the incident sound beam strikes the boundary at any angle other than 90 degrees oblique incidence synonyms - Answers -Not right angle -Non-perpendicular normal incidence - Answers the incident sound beam strikes the boundary at exactly 90 degrees normal incidence synonyms - Answers perpendicular, orthogonal, right angle, 90 degrees oblique angles - Answers angles with a measure other than 90 degrees obtuse angle - Answers more than 90 degrees right angle - Answers 90 degree angle acute - Answers less than 90 degrees incidence - Answers the angle at which the wave strikes the boundary impedance - Answers the acoustic resistance to sound traveling in a medium reflection of an us wave depends on the differences in acoustic impedances of two media at a boundary Impedance equation - Answers impedance (rayls) = density (kg/m^3) x propagation speed (m/s) thick half value - Answers -Low frequency sound -Media with low attenuation rate thin half value - Answers -High frequency sound -Media with high attenuation rate half value layer thickness - Answers distance sound travels in a tissue that reduces the intensity of a sound to 1/2 its original value depends on medium and frequency of sound half value layer thickness synonyms - Answers penetration depth, depth of penetration, and half-boundary layer attenuation coefficient in soft tissue - Answers in soft tissue the attenuation coefficient (dB/cm) and the frequency (mHz) are directly related the attenuation coefficient is 1/2 the frequency attenuation coefficient - Answers the number of decibels of attenuation that occurs when sound travels one centimeter absorption - Answers occurs when ultrasonic energy is converted into another energy (heat) Rayleigh scattering - Answers organized and omnidirectional (all directions) proportional to frequency^4 lower frequency beams - Answers scatter less higher frequency beams - Answers scatter more scattering - Answers random redirection of sound in many directions is disorganized and chaotic directly related to frequency disadvantage of diffuse reflection - Answers backscattered reflections have a lower strength advantage of diffuse reflections - Answers interfaces at suboptimal angels to the sound beam can still produce reflections that will return to the transducer consequences of using backing material - Answers decreased sensitivity wide bandwidth low quality factor limitations of specular reflectors - Answers when wave is slightly off axis, the reflection does not return to the transducer digital numbers - Answers computer world, limited choices, discrete values spatial resolution - Answers image detail advantages of digital scan converter - Answers uniformity- consistent grey scale quality throughout the image stability- does to fade/drift durability- not affected by age/ heavy use speed- nearly instant processing accuracy- error free two important elements of digital scan converter - Answers pixel and bit pixel density - Answers the number of picture elements per inch low pixel density - Answers few pixels per inch larger pixels less detailed image lower spatial resolution high pixel density - Answers many pixels per inch smaller pixels more detailed image higher spatial resolution pixel - Answers from term picture element smallest building block of digital picture Bit - Answers binary digit smallest amount of computer memory binary number - Answers a group of bits and is simply a series of zeroes and ones ex: Byte - Answers a group of 8 bits of computer memory word - Answers consists of two bytes or 16 bits fewer bits per pixel - Answers fewer shades of gray, degraded contrast resolution more bits per pixel - Answers more shades of gray, improved contrast resolution digital-to-analog converter (D-to-A) - Answers digital scans cannot be directly displayed on analog display devices the digital signals must be translated back into analog form through D-to-A preprocessing - Answers manipulation of image data before storage -tgc -log compression -write mag -persistence -spatial compounding -edge enhancement -fill in interpolation postprocessing - Answers manipulation of image data after storage -any change after freeze frame - b/w inversion -read magnification -contrast variation -3D rendering Read magnification - Answers Occurs after the image data is stored in the scan converter 1. us system sans anatomy 2. image converted from analog digital form and stored in scan converter 3. sonographer identifies region of interest and the system reads and displays the original data only write magnification - Answers applied during data acquisition before storage in scan converter 1. us sys scans anatomy creates image 2. image converted from analog to digital from and is stored in scan converter 3. sonographer identifies region of interest 4. us sys rescans region of interest only read magnification - Answers (read zoom) uses old data post processing (after freezing) larger pixel size same number of pixels in original region of interest unchanged spatial resolution unchanged temporal resolution cannot reverse write magnification - Answers (write zoom) acquires new data preprocessing identical pixel size more pixels than the original region of interest improved spatial resolution may improve temporal resolution reversed coded excitation - Answers creates very long sound pulses containing a wide range of frequencies. this specially designed long pulse distributes energy over a broad frequency range improved penetration results *occurs in pulser* coded excitation provides - Answers -higher signal-to-noise ratio -improved axial resolution -improved spatial resolution -improved contrast resolution -deeper penetration spatial compounding - Answers method of using sonographic information from several different imaging angles to produce a single image frequency compounding - Answers an advanced technique that reduces speckle artifact and noise in ultrasound images. all reflected sound pulses contain a large range of frequencies edge enhancement - Answers image processing method that makes pictures look sharper, works by increasing image contrast in area immediately around the edge temporal compounding - Answers (time averaging, persistence, temporal averaging) continues to display info from older images produces a smoother image with reduced noise, higher signal to noise ratio and improved image quality is produced limitation of temporal compounding (persistence) - Answers reduction in displayed frame rate, which reduces temporal resolution. most effective with slowly moving structures, less useful with rapidly moving structures fill in interpolation - Answers interpolation is a method of constructing new simulated data pints to fill in the gaps goal is to fill in gaps of missing data form of preprocessing line density increases improving spatial resolution energy technology - Answers based on differing stiffness and differentiates the layers more effectively PACS - Answers picture archiving and communication system virtually instant access to archived studies no degradation of data store and fwd telemedicine the ability to electronically transmit images and reports to remote sites how are info/images stored in PACS - Answers computer hard drives are the primary digital storage devices DICOM - Answers digital imaging an computers in medicine set of rules/protocols that allows imaging systems to share info on a network Dynamic Range (dB) - Answers method of reporting the extent to which a signal can vary and still be accurately measured "number of available choices" dynamic range of components - Answers transducer:120Db Receiver: 100-120dB Scan converter: 40-50dB Display: 20-30dB Archive: 10-30dB dynamic range of info decreases the more its processed number of choices - Answers alternative description of dynamic range the dynamic range of display can be reported as the number of possible gray shades narrow dynamic range - Answers fewer gray shades - high contrast bistable image- contains only b/w has narrowest dynamic range wide dynamic range - Answers many shades of gray- low contrast gray scale image - many shades of gray harmonic imaging - Answers creation of an image from sound reflections at twice the frequency of the transmitted sound fundamental frequency - Answers the frequency of sound created by the transducer and transmitted into the body harmonic frequency - Answers twice the fundamental frequency (also called second harmonic frequency). fundamental image - Answers image created by processing reflections that have the same frequency as the transmitted sound harmonic image - Answers image created by processing reflections that are twice the fundamental frequency linear behavior - Answers proportional or symmetrical. Linear systems respond in an even manner. nonlinear behavior - Answers irregular or disproportionate. A system is nonlinear when it behaves unevenly. Harmonic frequency sound arises from nonlinear behavior tissue harmonics - Answers energy converted from the fundamental frequency to the harmonic frequency the strength of the harmonic wave grow as sound travels in tissue What nonlinear behavior creates tissue harmonics? - Answers uneven speeds what is significant the only strong sound beams create harmonic signals - Answers beams that are most likely to create harmonics are least likely to create artifacts summary of tissue harmonics - Answers not present as sound leaves transducer, created deeper in tissues. created during transmission created by nonlinear behavior. Primarily created along the main axis of the beam. minimizes side lobes pulse inversion harmonics - Answers imaging technique specifically designed to utilize harmonic reflections, which are distortion free, while eliminating distorted fundamental reflections contrast agents - Answers Substances ingested, injected, or in some way instilled into the body to improve visibility of specific organs, structures, or pathology contrast agents must - Answers be safe be metabolically inert long lasting strong reflectors of us small enough to pass through capillaries contrast harmonics - Answers created during reflection as energy is converted from fundamental frequency to the harmonic frequency what non linear behavior of a micro bubble creates contrast harmonics - Answers nonlinear changes in bubble size called resonance when exposed to low pressure component of a sound beam bubble expands bubbles expand to a greater extent than they shrink what is mechanical index (MI) - Answers the amount of contrast harmonics produced estimated by a number depends on frequency of transmitted sound Lower MI - Answers -small pressure variation -higher frequency Higher MI - Answers large pressure variation, lower frequency hemodynamics - Answers the study of blood moving through the circulatory system flow - Answers also called volume flow rate indicates the volume of blood moving during a particular time flow equation - Answers volume/time Velocity - Answers speed or swiftness of a fluid moving from one location to another velocity equation - Answers distance/time 3 forms of velocity - Answers pulsatile phasic steady pulsatile flow - Answers -occurs when blood moves with a variable velocity -blood accelerates and decelerates as a result of cardiac contraction -commonly appears in arterial circulation phasic flow - Answers Occurs when blood moves with variable velocity. Blood accelerates and decelerates from respiration often appears in venous circulation steady flow - Answers smooth/ no change in speed occurs when a fluid moves at a constant speed/velocity steady flow is present in venous circulation when individuals stop treating for a brief moment laminar flow - Answers NORMAL flow streamlines are aligned and parallel characterized by layers of blood that travel at individual speeds plug flow - Answers occurs when all the layers and blood cells travel at the same velocity form of laminar flow parabolic flow - Answers -bullet shaped profile -velocity is highest in the center of the lumen and gradually decreases to its minimum at the vessel wall form of laminar flow turbulent flow - Answers associated with pathology characterized by chaotic flow patterns in many different directions and at many speeds streamlines = obliterated small hurricane like pattern this is called eddy current/vortex murmur (bruit) - Answers turbulent flow converts flow energy into forms such as sound/ vibration tissue vibration associated with turbulence is called thrill (can feel with fingertips) Reynolds number - Answers predicts whether flow is laminar or turbulent laminar less than 1500 turbulent greater than 2000 energy gradient - Answers blood moves from regions of higher energy to lower energy forms of energy - Answers kinetic, pressure, gravitational kinetic energy - Answers associated with a moving object determined by objects mass and speed at which it moves pressure energy - Answers form of stored energy/potential energy has ability to perform work creates flow by overcoming resistance gravitational energy - Answers form of stored/ potential energy associated with any elevated object energy losses in the circulation - Answers viscous loss, frictional loss, inertial loss viscous energy loss - Answers viscosity describes the thickness of a fluid; more energy is lost the thicker the fluid is associated with blood overcoming its internal stickiness units: poise hematocrit - Answers % of blood made up of red blood cells normal value approx 45% viscous energy loss is determined by this frictional energy loss - Answers occurs when flow energy is converted to heat as one object rubs against another ex blood sliding against vessel walls inertial energy loss - Answers energy is lost when the speed of a fluid changes, regardless of whether the fluid speeds up or slows down inertia relates to the tendency of a fluid to resist changes in its velocity inertial energy loss occurs during - Answers -pulsatile flow (arterial circulation) -phasic flow (venous circulation) -velocity changes at a stenosis velocity increases as the vessel narrows velocity decreases as blood flows out of stenosis into a vessel segment of normal diameter stenosis - Answers narrowing in the lumen of a vessel effects of a stenosis - Answers change in flow direction increased velocity as vessel narrows turbulence downstream from the stenosis pressure gradient across the stenosis loss of pulsatility Bernoulli's Principle - Answers describes the relationship between velocity and pressure in a moving fluid pressure gradient increases when - Answers flow increases or resistance increases flow increases when - Answers pressure gradient increases or resistance decreases Ohms - Answers electrical resistance is reported in these units resistance vessels - Answers arterioles hydrostatic pressure (mmHg) - Answers pressure related to the weight of blood pressing on a vessel measured at a height above or below heart level supine - Answers lying on the back hydrostatic pressure is zero hydrostatic pressure in the supine patient with a bp of 140 mmHg - Answers at heart level ankle, knee, midcoast, top of head = 140 mmHg inspiration - Answers diaphragm moves downward, chest cavity expands, creating negative pressure in the chest venous flow from head, arms and vena cava increase abdominal compression increases venous blood in legs decreases expiration - Answers diaphragm moves upward increase in thoracic pressure reduces venous return to heart venous flow from head, arms, and vena cava decrease Doppler Shift (Doppler frequency) - Answers Difference between received and transmitted frequencies demodulation - Answers process of extracting the low doppler frequency from the transducers carrier frequency doppler shift - Answers doppler shift (Hz)= reflected frequency - transmitted frequency creation of frequency shift - Answers transmitted sound waves strike moving red blood cells positive doppler shifts - Answers - when blood cells move toward the transducer - reflected frequency is higher than the transmitted frequency negative doppler shifts - Answers - when blood cells move away from the transducer - reflected frequency is lower than the transmitted frequency speed - Answers purely magnitude indicates the distance that a red blood cell moves in 1 sec units- cm/s velocity - Answers defines by magnitude and direction doppler equation - Answers doppler shift = 2 x velocity of blood x transducer frequency x cos0 / propagation speed *60 is best* relationship between the transmitted frequency and doppler shift - Answers doppler shift is directly related to the frequency of transmitted sound, transducer frequency is doubled, measured dopp shift will also be doubled doppler shift measured in hertz - Answers -directly related to velocity -directly related to transducer frequency what is the relationship between cosine and doppler shift - Answers dopp shift is directly related to the cosine of the angel between the direction of flow and direction of sound they are directly related relationship between actual and measured velocities when blood moves perpendicular to sound beam - Answers dopp shifts and velocities cannot be measured with perpendicular incidence cosine of angles - Answers 0 - 1.0 30 - 0.87 60 - 0.5 90 - 0 120 - -0.5 150- -0.87 180 - -1.0 at angels other than 0 and 180 only a portion of the true velocity is measured bidirectional doppler - Answers positive dopp shift indicates flow toward xducer negative dopp shift indicates flow away from xducer flow toward xducer - Answers displayed above baseline flow away from xducer - Answers displayed below baseline phase quadrature - Answers (quadrature detection) commonly used to signal processing technique for bi directional doppler cont wave doppler - Answers requires 2 crystals in the xducer 1 crystal constantly transmits 2nd crystal constantly receives reflections from blood cells advantage and disadvantage of CW dopp - Answers adv- ability to accurately measure very high velocities disadv- exact loc of moving blood cells can't be determines, lacks tgc range ambiguity - Answers doppler signals arise from all blood cells in the region of overlap between transit and receive beams cont wave xducers - Answers dedicated cw xducers are relatively simple because it does not create anatomic images contains 2 elements each shaped like a semi circle duplex imaging - Answers simultaneous anatomic imaging and doppler result of cw xducer not using backing material - Answers undampened transmitted signal narrow bandwidth higher quality factor higher sensitivity pulsed wave doppler - Answers only one PZT crystal necessary crystal alternates between sending and receiving sound pulses PWD Advantages - Answers being able to select the exact location where velocities are measured -range resolution -raange specificity -freedom from range ambiguity artifact sample volume (gate) - Answers sonographer postions a small marker on a two dimensional image. US sys then calculates the time-of-flight for a sound pulse traveling to and from gate - echo created at the gate PWD transducers - Answers contain backing material -low quality factor -lower sensitivity -wide bandwidth pulses