New Quiz 19 Dec Welcome to your MRI - A Name [The depth of a volume element is determined by what parameter?] Matrix NEX Repetition time Slice thickness None . [In conventional spin echo sequences, how many phase encoding steps must be selected to fill 128 lines of K space?] 64 128 192 256 None . [As slice thickness increases, the effects of time of flight phenomenon ______. ] Increase Decrease Stay the same None . [Isolating the RF transmitter from the RF receiver is known as _____.] Deisolation Isolation Coupling Decoupling None . [An example of phase mismapping artifact is ______. ] Cardiac motion Flow motion Respiratory motion All of the above None . [When the direction of blood flow is opposite the direction in which slices are acquired, the effects of entry slice phenomenon ______.] Increase Decrease Stay the same None . [When field of view is increased, signal to noise ratio _______.] Increases Decreases Stays the same None . [Figure is a diagram showing what type of pulse sequence?] Partial saturation Spin echo Inversion recovery Gradient echo None Comment . [The type of RF coil configuration that is used to image anatomical structures close to the surface of the patient is known as a _____.] Surface coil Quadrature coil Phased array coil Shim coil None . [When the phase encoding gradient is activated, medium slopes produce what type of signal amplitudes?] High Low Medium None of the above None . [The X gradient alters the magnetic field strength along which axis?] Horizontal axis Vertical axis Long axis Short axis None . [Typical peak velocities of the proximal carotid, brachial and superficial femoral arteries are usually within what range?] 150 - 175 cm/sec 100 - 160 cm/sec 80 - 120 cm/sec 40 -70 cm/sec None . [Gradient echo pulse sequences that preserve left over transverse magnetization are said to be ______. ] Incoherent Coherent Consistent Inconsistent None . [Figure displays an example of what type of artifact?] Magnetic Susceptibility Phase wrap RF zipper Both A and C None Comment . [The gradient echo pulse sequence that is characterized by an echo time that is longer than its repetition time is known as ______.] Echo planar Steady state free precession Spin echo Fast spin echo None . [In a gradient echo pulse sequence, the process of eliminating residual transverse magnetization is known as ______.] Warping Spoiling Rewinding None of the above None . [At a field strength of 1.0 tesla, the approximate Tl relaxation time for water is ______.] 800ms 1000 ms 2000 ms 2500ms None . [The liquids used to cool the wire in the main magnetic field of a superconducting magnet are known as _____.] Neon gases Plasma Cryogens None of the above None . [Hydrogen nuclei begin to precess in phase when which of the following occurs?] The proper RF is turned off The patient is placed into the external magnet The proper RF is turned on None of the above None . [Which of the following is a contraindication for the use of gadolinium?] Patients with history of metastatic cancer Patients with history of asthma Patients with history of metal implants No known contraindications None . Time's up
