New Quiz 19 Dec Welcome to your MRI - A Name [Which of the following is the pulse sequence that is used most commonly?] Inversion recovery Gradient echo Spin echo Echo planar None . [Which of the following is a disadvantage of using a permanent magnet in clinical MRI?] Low fringe field Low operating cost Low field strength Both A and B None . [Peripheral gating is a technique used to decrease what type of motion artifact?] CSF pulsation motion Cardiac motion Swallowing Respiratory motion None . [In Figure, at a TR of 200, which of the following tissues has the greatest signal intensity?] Tissue A Tissue B Tissue C None Comment . [On a T2 weighted image of the brain, grey matter appears______ to white matter.] Hyperintense Hypointense Isointense None . [Which of the following is a possible side effect of gadopentetate dimeglumine?] Mild, temporary headaches Nausea Vomiting All of the above None . [The type of RF coil configuration that uses a pair of coils perpendicular to each other to transmit and receive signal is known as a _____.] Surface coil Phased array coil Quadrature coil Shim coil None . [The inversion recovery pulse sequence that is used to suppress CSF in proton density and T2 weighted images is known as______.] FLAIR STIR SSFP FISP None . [The type of shimming that is achieved by adjusting the electrical current in specialized coils is known as _____.] Passive shimming Passive shielding Active shimming Active shielding None . [Entry slice phenomenon is most prominent in what slice of the area scanned?] First slice Middle slice Last slice Affects all the same None . [Dephasing of the net vector in the transverse plane is known as _______.] Tl relaxation Spin-Lattice relaxation Longitudinal relaxation Spin-Spin relaxation None . [Material that is weakly attracted to a magnetic field is said to be _______.] Electromagnetic Paramagnetic Ferromagnetic Diamagnetic None . [After being placed in an external magnetic field, low energy hydrogen nuclei point in which direction?] Parallel Anti-paired Anti-parallel Perpendicular None . [In clinical MRI, superconducting magnets usually operate at field strengths from _____.] .15 to .3 tesla .5 to 2.0 tesla 2.5 to 4.0 tesla Over 4 tesla None . [Specific absorption rate is dependent upon which factor(s)?] Induced electrical field and tissue density Patient size and pulse duty cycle Tissue conductivity All of the above None . [Biological effects associated with exposure to static magnetic fields above 2 tesla include which of the following?] Fatigue Headaches Hypotension All of the above None . [When pixel size increases, signal to noise ratio _______.] Increases Decreases Stays the same None . [Figure displays an example of what type of artifact?] Aliasing Truncation Chemical shift Phase mismapping None Comment . [Which method of image acquisition acquires data from an entire volume of tissue, then uses a method called slice encoding to separate the images?] Sequential 2D volumetric 3D volumetric None . [The gradient echo pulse sequence that produces true T2 image weighting is known as ______.] SSFP T2FFE PSIF All of the above None . Time's up
