Modalities (Chapter 9-Ultrasound) Review Questions with Verified Answers Already Passed

Modalities (Chapter 9-Ultrasound) Review Questions with Verified Answers Already Passed What are the ideal parameters for using ultrasound to treat a pressure ulcer? - Answers 3MHz, 0.5-1.0 W/cm^2, pulsed 20% -Overall, the studies published so far indicate that pulsed ultrasound may facilitate wound healing, but good evidence of this effect is lacking. -The treatment parameters that have been found to be effective for this application are 20% duty cycle, 0.8-1.0 W/cm^2 intensity, 3 MHz frequency, for 5-10 minutes What are the ideal treatment parameters for using ultrasound to treat pain via stimulation of cutaneous thermal receptors? - Answers 3 MHz, 0.5 W/cm^2, continuous -Only continuous ultrasound provides significant thermal effects to activate thermoreceptors, The treatment parameters that have been found to be most effective for control of pain are continuous ultrasound at 0.5-2.0 W/cm^2 intensity and 1.5 MHz freequency Which of the following accurately describes the cause and effect relationship of ultrasound? - Answers Increased frequency: decreased depth of penetration -The correct answer is increased frequency: decreased depth of penetration because higher freqeucny sound waves penetrate less deeply Attenuation of ultrasound is caused by all of the following EXCEPT: - Answers Repulsion -Attenuation is the result of absorption, reflection, and refraction with absorption accounting for about 50% of attenuation. -Attenuation is greatest in tissues with high collagen content and with the use of high ultrasound frequencies. -Repulsiton is not a cause of ultrasound attenuation What is the most common adverse effect of ultrasound? - Answers Burns Although adverse effects are rare, the most common adverse effect is a burn. -To minimize the risk of burning a patient, always move the ultrasound head and do not apply thermal-level ultrasound to areas with impaired circulation or sensation. -Reduce the ultrasound intensity in ares with superficial bone or if the patient complains of any increase in discomfort Which of the following statements is true given the same ultrasound intensity in all cases? - Answers 1 MHz will penetrate deeper than 3 MHz although temperature will be less -With 3 MHz ultrasound, as compared to 1 MHz ultrasound, and in tissues with higher collagen content, the depth of penetration is lower, although the maximum temperature achieved is higher. -1 MHz frequency ultrasound is considered best for heating tissues up to 5 cm deep -3 MHz frequency is considered best for heating tissues only 1-2 cm deep What are the ideal treatment parameters for using ultrasound to modulate inflammation? - Answers 1-3 MHz, 0.5-1.0 W/cm^2, pulsed 20% -It is recommended that ultrasound be applied in a pulsed mode at a low intensity (0.5-1.0 W/cm^2) during the acute phase of tendon inflammation to optimized healing and minimize the risk of aggravating the condition What are the treatment parameters for using ultrasound before stretching shortened soft tissue? - Answers 1-2 W/cm^2, coninuous -Of the options listed, coninous ultrasound is the only one that generates thermal effects such as increased tissue extensibility -Pulsed ultrasound has primarily non-thermal effects When using ultrasound for its thermal effects, what is the range of tissue temperature you should try to achieve? - Answers 40-45 degrees C -the minimal theraputic level is 40 degrees C and should not exceed 45 degrees C All of the following are desired outcomes of ultrasound EXCEPT: - Answers Blood cell stasis -Blood cell stasis is an adverse effect of ultrasound, as is infection or cross-contamination between patients The effective radiating area of the sound head is: - Answers Always smaller than the size of the sound head -The effective radiating area is always smaller than the area of the treatment head because the crystal does not vibrate uniformly and must be smaller than the size of the outside of the sound head Which of the following is the LEAST effective method for determining if continuous ultrasound is reaching therapeutic levels? - Answers Check to be sure that the setting are on the appropriate frequency and at the highest intensity recommended for the tissue being treated -Use of appropriate setting does not prove effectiveness. -The best way to determine if ultrasound is reaching therapeutic levels is to have a baseline for desired outcome and measure it objectively following treatment