Which of the following statement is false about magnetic resonance imaging? the

Question

Which of the following statement is false about magnetic resonance imaging? the MRI signal represents a time- and position-dependent magnetization function, where position dependency is based on the addition of magnetic field gradients and phase differences to the basic magnetic Held B_0. T_1, or spin-lattice relaxation, describes the recovery of a spin to its equilibrium magnetization along the z-axis. while T_2, or spin-spin relaxation, describes the gradual dephasing of any component of the magnetization in the xy-plane, towards random phase that equates with a null transverse component. the Spin-Echo pulse sequence is based on a 90-degree flip angle soon followed by a 180- degree flip angle that reverses the effect of magnetic inhomogeneity and causes the portion in the xy-plane of the magnetization to briefly rephase. Frequency encoding has no effect on the Larmor frequency of spins. None of these statements is false. Which is true of the Gaussian function? One way of computing the derivative of noisy signal is to smooth with a Gaussian before taking the derivative. Now, because differentiation and convolution arc both linear operators we can invert their order and thereby compute the derivative of the smoothed signal by simply convolving the raw signal with the derivative of a Gaussian. Gaussian filtering in 2D can be decomposed into two 1D Gaussian filtering operations. Convolution of a signal with a Gaussian filter in the spatial domain equates with multiplication of the Fourier transform of the signal with the Fourier transform of the Gaussian (which is a Gaussian also) in k-space. A Gaussian filter acts as a low-pass filter. All of the above are true.

Explanation / Answer

3. d)

4. e)

Related Questions

Navigate

• Browse (All)
• Browse W
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.