Edelman Book Questions

312. A PZT crystal in the shape of a disc produces continuous ultrasound wave. T/F? If the diameter of the acoustic beam produced by a crystal is 8mm at a depth of twice the near zone length, then the PZT crystal has a diameter of 8mm.

True.

316. A PZT crystal in the shape of a disc produces continuous ultrasound wave. T/F? The greater the diameter of a transducer's PZT crystal, the longer the near zone length is.

True.

346. True or False? In comparison to the other locations along the length of an ultrasound beam, focusing is generally ineffective in the far zone.

True.

367. True or False? All phased array transducer systems direct ultrasound pulses in many directions to create a two-dimensional image.

True.

376. True or False? Annular phased array transducers focus sound beams in all planes and at all depths.

True.

333. True or False? When using standard ultrasonic imaging instrumentation, the lateral resolution has a higher numerical value than the axial resolution.

True. A sound pulse is usually wider than half its length. Meaning lateral resolution will have a higher number.

310.A PZT crystal in the shape of a disc produces continuous ultrasound wave. T/F? The far zone is the only region where the beam diameter exceeds the transducer diameter

True. Beam diameter exceeds transducer diameter only in the far zone.

337. True or False? When using an instrument typical of today's diagnostic imaging devices, a higher frequency transducer is likely to improve the axial resolution.

True. Higher frequency = shorter pulse lengths. Good axial res = short pulses

402. True or False? With sector scanning, images with greater detail (spatial resolution) are created when the number of acoustic pulses per degree of sector is increased.

True. More pulses the better

331. True or False? The pulse duration does not profoundly influence the lateral resolution.

True. The main determinant of lateral res is beam diameter.

361. T/F? With regard to mechanical transducers, the ultrasound beam is not electronically focused.

True. Usually an acoustic lens or curved PZT crystal

336. True or False? When using an instrument typical of today's imaging devices, a higher frequency transducer is likely to mildly improve the system's lateral resolution.

True. With all other variables equal, pulses made with higher frequency sound are somewhat narrower than low frequency pulses.

370. True or False? The "curved pattern" of delays in the electrical spikes used in a linear phase array transducer focuses the beam during transmission.

True. focusing using time delays of the electrical spikes is a form of focusing.

372. True or False? Both linear and phased array technologies have the ability to variable focus an ultrasound beam to different depths.

True. it's all about the phased array

398. True or False? An ultrasound system with a shorter pulse repetition period (PRP) will have better temporal resolution than a system with a longer PRP.

True. shorter PRP = more pulses per second.

394. True or False? The length of a pulse does not directly influence the temporal resolution.

True. temporal resolution is determined by depth, sector, line density and number of foci

362 T/F? With regard to mechanical transducers, there is communication between the pulser of the ultrasound system and the PZT crystal of the transducer.

True. the PZT must be directly connected to the pulser by a wire.

313. A PZT crystal in the shape of a disc produces continuous ultrasound wave. T/F? The near zone is the only region where the diameter of the sound beam decreases as depth increases.

True

360. T/F? With regard to mechanical transducers, the ultrasound beam is directed in many different directions to create an imaging plane.

True

381. Which transducer steers the beam with a motor and focuses with an acousic lens or curved PZT element?

mechanical

344. All of the following occur with focusing except: A. lower intensity at the focus B. shorter near zone length C. more compact focal zone D. smaller diameter beam diameter at the end of the near zone

A. Focusing does not lower beam intensity

329. The lateral resolution of an ultrasound system is primarily determined by the _____. A. width of the sound pulse B. length of the ultrasound pulse C. duration of the sound pulse D. none of the above

A

341. Which of the following techniques is external focusing? A. lens B. curved crystal C. electronic

A.

369. The pattern of electrical signals exciting the piezoelectric crystals of a linear phased array transducer _____. A. typically changes from one acoustic pulse to the next B. changes every fourth or fifth acoustic pulse C. changes only when the maximum imaging depth changes D. none of the above

A.

396. Which two factors determine temporal resolution? A. speed of sound and depth of view B. pixel size and sector size C. focal zones and sector depth D. propagation speed and frame rate

A.

352. Which imaging technique usually displays a single jagged line of varying heights? A. A-mode B. B-mode C. C-mode D. I-mode

A. A-mode has echo amplitude on the y-axis and reflector depth on x-axis

326: Which of the following explains the difference in sound beam shape created by a disc-shaped crystal from that of a small chip of PZT? A. Huygens' Principle B. Snell-s Law C. Bernoulli's Law D. Murphy's Law

A. Huygens' explains the difference between beam shape from tiny chips of PZT and disc crystals of a larger dimension.

390. What is the use of a greater number of channels to receive echoes from ever increasing depths called? A. dynamic aperture B. apodization C. dynamic frequency tuning D. subdicing

A. `

388. What is the advantage of using a 1 1/2 dimensional array transducer? A. improved elevational resolution B. improved lateral resolution C. improved axial resolution D. improved temporal resolution

A. creates a thinner imaging plane, which gives superior elevational resolution

356. To which of the following do the x-axis of a B-mode, the y-axis of an M-mode and the x-axis of an A-mode all relate? A. depth of view B. go time C. echo amplitude D. time of flight

A. depth

328. The focus of an ultrasound beam is the location where the _____. A. beam is the broadest B. optimum transverse resolution is C. frequency is the highest D. finest depth resolution is obtained

B

364. Which two of the following terms are associated with phased array transducers? A. lens B. multi-focus C. mirror D. adjustable E. external

B and D.

349. The diameter of a disc-shaped, unfocused piezoelectric crystal is 1.2 cm. The near zone length is 8 cm. What is the best estimate for the lateral resolution at a depth of 16 cm? A. 0.6 cm B. 1.2 cm C. 8 cm D. 16 cm

B.

366. Which best describes the elements in a linear phased array transducer? A. rectangular, 1/4 wavelength thick B. rectangular, 1/2 to 1/4 wavelength wide C. circular D. squares, 1/2 wavelength thick

B.

399. What is the primary disadvantage of multiple focal zones along each scan line of a two-dimensional image? A. improved temporal resolution B. decreased temporal resolution C. improved lateral resolution D. improved longitudinal resolution

B.

401. Which choice will result in increased frame rate and temporal resolution? A. decreased propagation speed B. decreased sector size C. decreased lateral resolution D. decreased pulse repetition frequency

B.

365. The minimum number of active elements in a mechanical transducer is: A. 0 B. 1 C. 2 D. none of the above

B. 1.

348. The diameter of a disc-shaped, unfocused piezoelectric crystal is 1 cm. What is the best estimate for the minimum lateral resolution of the ultrasound system? A. 1 mm B. 5 mm C. 1 cm D. 5 cm

B. 5mm Beam still has hourglass shape, being more narrow at focus. Approx 1/2 the beam diameter

319. For a disc-shaped PZT crystal producing continuous sound, which design will create a beam with the deepest focus? A. large diameter, low frequency B. large diameter, high frequency C. small diameter, low frequency D. small diameter, high frequency

B. A CW transducer producing the longest near zone (deepest focus) will have a large diameter and a high frequency.

345. In which region of a sound beam is focusing most effective? A. the very shallow near zone B. the end of the near zone C. very deep in the far zone D. throughout its entire length

B. End of near zone is the focal zone.

340. Which of the following techniques is internal focusing? A. lens B. curved crystal C. electronic

B. Focusing with a curved PZT crystal is internal focusing.

321. Two systems are identical except for the frequency of the emitted pulse. Which system will have the deeper focus? A. the lower frequency system B. the higher frequency system C. both foci will be at the same depth

B. Frequency and focal depth are directly related.

322. As sound travels deeply into the far zone, the beam diverges, or spreads out. Which of the following will result in a minimum beam divergence deep in the far zone? A. small diameter, high frequency B. high frequency, large diameter C. large diameter, low frequency D. low frequency, small diameter

B. Large diameter crystals produce less beam divergence in far zone. Waves from small diameter, low frequency crystals are more divergent.

355. The mode that produces lines related to the changing position of reflectors in the body with respect to time is called _____. A. A-mode B. M-mode C. B-mode D. a la mode

B. M-mode (motion)

332. Two ultrasound systems have near zone lengths of 8 cm. At the focus, System G's lateral resolution is 3.0 mm, whereas System P's is 5.0 mm. Which system will produce higher quality pictures at their foci? A. System P B. System G C. both will be of similar quality

B. System G has a narrower beam.

320. Two ultrasound systems are identical except for the diameter of the transducer's piezoelectric crystal. Which system has the deepest focus? A. the system with the smaller crystal diameter B. the one with the larger diameter crystal C. their foci will be at the same depth

B. The larger the crystal diameter, the deeper the focus.

334. Two ultrasound systems have near zone lengths of 8 cm. At their foci, System Q's lateral resolution is 3.0 mm and System H's is 5.0 mm. Which system will correctly display two small structures at a depth of 8 cm? The objects are side by side and are 0.4 cm apart. A. System H B. System Q C. both produce similar quality pictures

B. The two objects side by side are .4cm OR 4.0 mm apart. So the lateral resolution of 3mm will be able to distinguish between the two echoes and the 5mm lateral res would make it appear as one single echo.

374. All of the following describe dynamic receive focusing except: A. delay pattern changes continuously throughout reception B. may be used by single crystal transducers C. focusing occurs at many depths D. automatically performed by system

B. only used with systems with array transducers

387. When looking at images produced by these transducer systems, which one can be distinguished from all the others? A. linear phased array B. linear switched array C. annular phased array D. mechanical transducer

B. switched (or sequential) make a rectangle, all the others make a sector shape

405. Of the following, which imaging modality has the poorest temporal resolution? A. two-dimensional, real-time B. A-mode C. color flow imaging D. M-mode

C

379. Which best describes the ELEMENTS in a linear sequential array transducer? A. rectangular, 1/4 wavelength thick B. rectangular, 1/4 to 1/2 wavelength wide C. rectangular, 1 wavelength wide D. squares, 1 wavelength thick

C.

380. What image is created with a two-dimensional array transducer? A. two-dimensional static image B. two-dimensional real-time image C. three-dimensional real-time image D. B-mode

C.

389. Which transducer possesses the best slice thickness resolution? A. linear phased arrays B. 2-D arrays C. 1 1/2 dimensional arrays D. linear sequential arrays

C.

400. what is the primary advantage of multiple focal zones along each scan line of a two-dimensional image? A. improved temporal resolution B. decreased temporal resolution C. improved lateral resolution D. improved longitudinal resolution

C.

408. A sonographer reduced the sector size from 90 degrees to 30 degrees. Frame rate, however, did not change. What else happened? A. imaging depth decreased B. pulse duration increased C. multi-focus was turned on D. PRF was increased

C.

318. For a disc-shaped PZT crystal producing continuous sound, which design will create a beam with the shallowest focus? A. large diameter, low frequency B. large diameter, high frequency C. small diameter, low frequency D. small diameter, high frequency

C. A CW transducer producing the shortest near zone (the most shallow focus) will have a small diameter and low emitted frequency.

354. Which imaging modality places dots of dissimilar gray scale on the display? A. A-mode B. I-mode C. B-mode D. M-mode

C. Brightness mode displays reflected echoes as spots of varying brightness. Stronger reflection=brighter dot

324. Two ultrasound systems are identical except for the pulse repetition period (PRP) of the emitted pulse. Which system will have the deeper focus? A. the system with the lower PRP B. the system with the higher PRP C. their foci will be at the same depth

C. Changes in PRP do not affect depth.

404. which of the following sector imaging systems will have the best image detail if all other parameters are identical? A. a 90 deg. sector with 100 pulses/image B. an 80 deg sector with 40 pulses/image C. a 70 deg. sector with 84 pulses/image D. a 60 deg. sector with 60 pulses/image

C. Divide 84/70= 1.2

343. Which of these techniques is consistent with variable or multi-focusing? A. lens B. curved crystal C. electronic

C. Electronic focusing is achieved with phasing of electronic signals.

392. which of the following will improve a system's temporal resolution? A. increased sector angle B. increased line density C. increased PRF D. increased frequency

C. Increase the number of images produced each second by increasing PRF

335. The lateral resolution of an ultrasound system is 4 mm. Two structures are separated by 3 mm and lie side by side in relation to the sound beam's main axis. What will most likely appear on the system's display? A. two weak echoes, 4 mm apart B. two bright echoes, 3 mm apart C. one echo D. two bright echoes, 7 mm apart

C. One echo. Both structures would appear in between the 4mm lateral beams. So it would appear as one echo.

378. How are the piezoelectric crystals excited when using an ultrasound system with a sequential linear array transducer? A. singly and in order: the first crystal, second, then the third, etc. B. in pairs: the first two crystals, the 3rd and 4th, the 5th and 6th, etc. C. in a specific order D. in a random sequence

C. Order of firing determined by manufacturer to produce highest quality image.

403. An ultrasound system with a 4.0 MHz transducer is used to image structures as deep as 15 cm. Twenty images are produced each second, each requiring 100 acoustic pulses. What is the PRF of the system? A. 1,500 Hz B. 300 Hz C. 2,000 Hz D. 4 MHz

C. PRF is # of pulses produced by a system in one second. 100 pulses construct one single image, and 30 images are displayed each second. so 2,000 pulses are used each second

353. With B-mode, on which axis is the strength of the reflection input? A. x-axis B. y-axis C. z-axis

C. reflection strength is z-axis

368. How are the piezoelectric crystals of a linear phased array transducer fired? A. in a single specific pattern B. in order, from top to bottom C. at exactly the same time D. at almost exactly the same time

D.

391. The excitation of array elements with dissimilar voltages is called _____ and is used to _______. A. dynamic aperture, reduce refraction B. subdicing, eliminate lobes C. apodization, remove flash artifact D. apodization, reduce lobe artifact

D.

395. Two imaging systems produce acoustic pulses; one pulse is 0.4 µsec long and the other is 0.2 µsec long. Which is most likely to provide the best temporal resolution? A. 0.4 µsec system B. 0.2 µsec system C. they are the same D. cannot be determined

D.

397. Which two controls determine a system's temporal resolution? A. frame rate and sector size B. focal zones and sector depth C. propagation speed and frame rate D. depth of view and pulses per image

D.

406. Which ultrasound imaging modality has the best temporal resolution? A. B-scanning B. duplex imaging C. color flow imaging D. M-mode

D.

351. Which imaging mode accurately displays reflector depth? A. I-mode B. L-mode C. C-mode D. A-mode

D. A-mode displays depth accurately, which is why it's used in Opthalmology.

350. Which imaging modality places time-of-flight information on the x-axis and echo amplitude on the y-axis? A. M-mode B. L-mode C. J-mode D. A-mode

D. A-mode. Depth on x-axis is determined by a pulse's time of flight. Strength of reflection on y-axis

342. Which of these terms means adjustable focusing or multi-focusing? A. dynamic aperture B. harmonics C. frequency agility D. phased array

D. All phased array transducers share one of these two features: 1.multi-focus capabilities 2. focal depth can be changed by sonographer

330. Two ultrasound systems produce acoustic pulses. One pulse is 0.4 µsec in duration and the other is 0.2 µsec. Which pulse will most likely provide the best lateral resolution? A. 0.4 µsec pulse B. 0.2 µsec pulse C. they are the same D. cannot be determined

D. Duration of pulse is unrelated to the lateral resolution.

377. What is true of the electrical pulses that excite the active elements of an annular phased array transducer? A. they arrive at each piezoelectric crystal at exactly the same time B. they vary in amplitude based on the direction of the steering and focusing C. they excite the crystals at different times, nanoseconds apart D. they arrive at each PZT crystal at different times, microseconds apart

D. Fires in a particular sequence to produce focused beam.

347. Two ultrasound systems have near zone lengths of 8 cm. At the focus, System S's lateral resolution is 3.0 mm, whereas System C's is 5.0 mm. Which system is most likely to appropriately display two small body structures that lie, one in front of the other, at depths of 8.6 and 9.0 mm? A. System C B. System S C. both have comparable quality D. cannot be determined

D. Insufficient info to answer. Axial resolution is not mentioned.

327. Huygens' Principle is based on ________. A. refraction B. constructive indices C. transverse waves D. interference

D. It explains the difference between the beam shape from tiny pieces of PZT and disc crystals of a larger dimension.

407. All of the following reduce temporal resolution by increasing the number of pulses per image except: A. increasing the number of foci B. increasing line density C. increasing field of view D. increasing depth of view

D. It still reduces temporal resolution, just not by increasing number of pulses

325. All of the following terms describe the shape of a sound wave created by a tiny fragment of PZT except: A. spherical B. Huygens' wavelet C. V-shaped D. hourglass shaped

D. Pieces of PZT create V-shaped waves. Choices A and B have the same meaning as V-shaped.

323. As sound travels deeply into the far zone, the beam diverges, or spreads out. Which of the following will result in the greatest beam divergence deep in the far zone? A. small diameter, high frequency B. high frequency, large diameter C. large diameter, low frequency D. low frequency, small diameter

D. Small diameter and low frequency cause the most divergence.

338. What will lower the value of an ultrasound system's lateral resolution? A. decrease the # of cycles in the pulse B. increase the effective damping material C. increase the pulse repetition period D. use an acoustic lens

D. To lower the numerical value of lateral resolution, the diameter of the beam must be reduced. This can be done by focusing the beam with an acoustic lens.

375. What is the shape of the elements in an annular phased array transducer? A. rectangles B. squares C. wedges D. circles

D. donut shaped crystals

373. Which of the following forms of focusing is different from the others? A. lens B. mirror C. phased D. dynamic receive

D. dynamic receive is accomplished during reception to reflected sound. the other three are transmission.

409. which of the following is not considered a component of an ultrasound system? A. master synchronizer B. pulser C. receiver D. image intensifier

D. that's part of an x-ray imaging system

317. A PZT crystal in the shape of a disc produces continuous ultrasound wave. T/F? The thicker a CW transducer's PZT crystal, the longer the near zone length is.

False, increasing the thickness of a crystal does not alter the length of the near zone of a CW ultrasound beam.

371. True or False? The "curved pattern" of a delays in the electrical spikes used in a linear phase array transducer focuses the beam during reception.

False. It's a form of transmission nor reception

363. T/F? With regard to mechanical transducers, foci exist at multiple depths as an ultrasound beam propagates through the body.

False. Mechanical transducers can only focus at a single, unchangeable point.

393. True or False? An ultrasound system with a longer pulse duration will generally have better temporal resolution.

False. Temporal resolution is unaffected by pulse duration

311.A PZT crystal in the shape of a disc produces continuous ultrasound wave. T/F? IF the diameter of a sound beam is 8mm at a depth EQUAL to TWICE the near zone length, then the PZT crystal has a diameter of 16mm.

False. The beam's diameter equals the crystals diameter at a depth of twice the near zone length.

314. A PZT crystal in the shape of a disc produces continuous ultrasound wave. T/F? If the narrowest diameter of a sound beam is at a depth of 8cm, then the PZT crystal's diameter is 16 cm.

False. The depth of the focus is not determined solely by the diameter of the PZT producing it.

315. A PZT crystal in the shape of a disc produces continuous ultrasound wave. T/F? The higher the frequency of the acoustic wave, the shorter the length of the near zone.

False. The focus get deeper as the frequency of the wave increases. With low frequency sound, the focus is shallower.

309.A PZT crystal in the shape of a disc produces continuous ultrasound wave. T/F? The near zone is the only region where the diameter of the sound beam is smaller than the transducer's

False. The sound beam created by a disc shaped CW crystal is smaller than the crystal in the near zone AND the initial part of the far zone.

358. Which transducers focus the beam electronically

Linear switched array, linear phased, annular phased array, convex or curvilinear array

357. Which types of transducers would the ultrasound beam be steered by a motor, a rotating reflecting mirror or a similar device?

Mechanical or annular phased array transducers. These are both mechanical devices.