Welcome to your MRI - A Name [On a TI weighted image of the brain, white matter appears ______ to grey matter.] Hyperintense Hypointense Isointense None . [The precessional frequency of hydrogen at .5 tesla is ______.] 42.6MHz 63.86MHz 25.48 MHz 21.28MHz None . [Which of the following logical gradients is known as the frequency encoding gradient?] X gradient Y gradient Z gradient None . [To exist, magnets must have two poles, therefore they are commonly called_______.] Vectors Dipoles Axis Both A and C None . [The image parameter that primarily affects T2 weighting is ______.] Echo time Inversion time Repetition time None of the above None . [During the sampling of signal, the sampling rate is directly proportional to the ______.] Sampling time Receive bandwidth Transmit bandwidth None of the above None . [The ratio that describes the constant at which any magnetic nucleus will precess in a 1 tesla magnet is known as _______.] Precessional ratio Magnetogyric ratio Gyromagnetic ratio Both B and C None . [Which of the following is the equation that is used to determine precessional frequencies?] Wo=yBo Bo=yWo F= yBo Both A and C None . [The precessional frequency of hydrogen at 1.0 tesla is ______.] 42.6MHz 63.86MHz 25.48 MHz 21.28 KHz None . [The process during the prescan that determines the amount of signal that is received is known as _____.] Center frequency adjustment Transmit gain adjustment Receive attenuation adjustment Impedance matching None . [Phase mismapping artifact always occurs in which direction of the MR image?] Frequency direction Phase direction Slice selection direction Readout direction None . [Which of the following people developed the most effective way to generate and transmit alternating current and has a magnetic unit of measurement named after him?] Michael Faraday Nikola Tesla Niels Bohr Jean Baptiste Joseph Fourier None . [Metal implants within the body, depending on the location, can pose what type of problems during the MRI exam?] Torque Heating Artifacts All of the above None . [The magnitude of the phase shifts between two points within a patient is determined by which factor?] Slope of the frequency encoding gradient Slope of the phase encoding gradient Strength of the RF pulse None of the above None . [When image matrix is increased, spacial resolution _______.] Increases Decreases Stays the same None . [The method of acquiring more than one echo that are multiples of each other to reduce intra-voxel dephasing is known as ______.] Gradient moment nulling Pre-saturation RF pulse Even echo rephasing None of the above None . [Within a perfect magnetic field all protons rotate at _______.] Different frequencies The same frequency Undetermined frequencies None of the above None . [Which of the following is the median lethal dose of Gadopentetate dimeglumine?] .5 mmol/kg 5 mmol/kg 1 mmol/kg 10-20 mmol/kg None . [Which of the following is the formula that is used to calculate blood flow velocity?] Velocity = Flow volume / Vessel area Velocity = Vessel area / Flow volume Velocity = Flow volume + vessel area Velocity = Vessel area - Flow volume None . [A saturation pulse is a technique used to reduce what type of motion artifact?] Blood flow motion Respiratory motion Swallowing motion All of the above None . Time's up
