MRI In practice chapter 1 Final Exam With Correct Detailed Answers 100% Verified.

Atomic Number - correct answer Sum of protons in the nucleus Mass number - correct answer Sum of protons and neutrons in the nucleus Isotopes - correct answer Atoms of elements with the same number protons but different number of neutrons Angular Momentum - correct answer Where the number of neutrons is slightly more or less then the number of protons, so spin directions are not equal and opposite, so the nucleus itself has a net spin MR Active Nuclei - correct answer Nuclei that have a net spin or angular momentum Magnetic Moment - correct answer When MR active nuclei have a net charge and are spinning, they automatically acquire this (motion + charge) Law of Electromagnetism - correct answer A magnetic field is created when a charged particle moves Classical Theory of Alignment - correct answer Some of the hydrogen nuclei align parallel with the magnetic field, while a smaller number of nuclei align anti-parallel Quantum Theory of Alignment - correct answer Low-energy nuclei align parallel with B0 and are termed spin-up nuclei, while high energy nuclei align anti-parallel to B0 and are termed spin-down nuclei Precession - correct answer Hydrogen nuclei spin on their own access, and B0 adds an additional spin Precessional Path - correct answer The circular path that the magnetic moments follow around B0 Precessional Frequency - correct answer The speed at which the magnetic moments precess around B0 The Larmor Equation - correct answer Precessional frequency = Magnetic Field Strength X Gyromagnetic ratio Gyromagnetic Ratio - correct answer Expresses the relationship between angular momentum and magnetic moment of each MR active nucleus Gyromagnetic Ratio of Hydrogen - correct answer 42.57 MHz/Tesla Resonance - correct answer Phenomenon that occurs when an object is exposed to an oscillating perturbation that has a frequency close to its own natural frequency of oscillation What must happen for resonance to occur? - correct answer An RF pulse of energy at exactly the Larmor/precessional frequency of hydrogen must be applied Excitation - correct answer The application of an RF pulse that causes resonance to occur Net Magnetization Vector (NMV) - correct answer The Magnetic Vector produced as a result of the alignment of excess hydrogen nuclei with B0 Flip Angle - correct answer The angle to which the NMV moves out of alignment Phase - correct answer The position of each magnetic moment on the precessional path around B0 In phase - correct answer When magnetic moments are in the same place on the precessional path around B0 Out of phase - correct answer When magnetic moments are not in the same place on the precessional path around B0 Faraday's Law of Electromagnetic Inuduction - correct answer If a receiver coil (conductor) is placed in the area of a moving magnetic field (the magnetization precessing in the transverse plane), a voltage is induced in this receiver coil Relaxation - correct answer The process by which hydrogen loses its energy Recovery - correct answer When the amount of magnetization in the longitudinally plane increases