5. Assume an MRI scanner imaging 'H with the following specifications: Bo = 3.0 T. Assume that with the Z-gradient on, the magnetic field strength is B0 at location Z = Zc: a. With a bandwidth of 1500 Hz, what is the gradient strength (G2) that would allow us to image a slice with 0.75 mm thickness? b. Using the gradient calculated in (a), we need to acquire an MR slice with the same slice width and positioned at 2.5 cm above the Zc position (Z = Zc +2.5 cm). What is the required RF excitation pulse center frequency (in MHz) for the slice selection pulse?

5. Assume an MRI scanner imaging 'H with the following specifications: Bo = 3.0 T. Assume that with the Z-gradient on, the magnetic field strength is B0 at location Z = Zc: a. With a bandwidth of 1500 Hz, what is the gradient strength (G2) that would allow us to image a slice with 0.75 mm thickness? b. Using the gradient calculated in (a), we need to acquire an MR slice with the same slice width and positioned at 2.5 cm above the Zc position (Z = Zc +2.5 cm). What is the required RF excitation pulse center frequency (in MHz) for the slice selection pulse?

Inquiry into Physics

8th Edition

ISBN:9781337515863

Author:Ostdiek

Publisher:Ostdiek

Chapter9: Optics

Section: Chapter Questions

Problem 6Q

See similar textbooks

Similar questions

(Indicates a review question, which means it requires only a basic understanding of the material to answer. Questions without this designation typically involve integrating or extending the concepts presented thus far.) . Just before the Sun sets, a driver encounters sunlight reflecting off the side of a building. Will Polaroid sunglasses stop this glare? Why or why not?
Radio telescopes are telescopes used for the detection of radio emission from space. Because radio waves have much longer wavelengths than visible light, the diameter of a radio telescope must be very large to provide good resolution. For example, the radio telescope in Penticton, BC in Canada, has a diameter of 26 m and can be operated at frequencies as high as 6.6 GHz. (a) What is the wavelength corresponding to this frequency? (b) What is the angular separation of two radio sources that can be resolved by this telescope? (c) Compare the telescope’s resolution with the angular size of the moon.
(Indicates a review question, which means it requires only a basic understanding of the material to answer. Questions without this designation typically involve integrating or extending the concepts presented thus far.) . What is polarized light? How do Polaroid sunglasses exploit polanzation?
A signal from of PLDT-Fibr travels through its optic cable at the speed of (2x108 m/s).a.) How long will it take for the signal to travel from our house to LJ’s house which has a30.35 km distance b.) What length in inches of the optic cable represents 0.75 ms(millisecond)?
CT scanners do not detect details smaller than about 0.5 mm. Is this limitation due to the wavelength of x rays? Explain.
The X-rays produced in the dentist’s office typically have a wavelength of 0.30 nm. What is the frequency of theserays?
ellow light has a wavelength l = 590 nm. How many of thesewaves would span the 1.35-mm thickness of a dime?
Give two lessons that may be learned from the unfortunate N-ray affair and other more recent incidents of uncorroborated and ultimately erroneous scientific reports that have been uncovered.
Check Your Understanding For the experiment in Example 4.4, show that m=20 is also a missing order.
A telescope can be used to enlarge the diameter of a laser beam and limit diffraction spreading. The laser beam is sent through the telescope in opposite the normal direction and can then be projected onto a satellite or the moon. (a) If this is done with the Mount Wilson telescope, producing a 2.54-m-diameter beam of 633-nm light, what is the minimum angular spread of the beam? (b) Neglecting atmospheric effects, what is the size of the spot this beam would make on the moon, assuming a lunar distance of 3.84108 m?
(Indicates a review question, which means it requires only a basic understanding of the material to answer. Questions without this designation typically involve integrating or extending the concepts presented thus far.) . Describe how you could use two large, circular Polaroid filters in front of a circular window as a kind of window shade.
The 305-m-diameter Arecibo radio telescope pictured in Figure 4.20 detects radio waves with a 4.00-cm average wavelength. (a) What is the angle between two just-resolvable point sources for this telescope? (b) How close together could these point sources be at the 2 million light-year distance of the Andromeda Galaxy? Figure 4.20 A 305-m-diameter paraboloid at Arecibo in Puerto Rico is lined with reflective material, making it into a radio telescope. It is the largest curved focusing dish in the world. Although D for Arecibo is much larger than for the Hubble Telescope, it detects radiation of a much longer wavelength and its diffraction limit is significantly poorer than Hubble’s. The Arecibo telescope is still very useful, because important information is carried by radio waves that is not carried by visible light. (credit: Jeff Hitchcock)