practice test 1 armrit Questions and Answers(A+ Solution guide)

different tissues that have signals that appear similar on a mr image are described as: - Answerisointense In a large main magnetic field such as those employed in MRI, the motion of a hydrogen proton has been described as wobbling like a spinning top. This motion is called: - Answer-Prescession Magnetic resonance imaging is derived from the process known as: - Answer-Nuclear magnetic resonance Once the net magnetization vector (nmv) has moved away from equilibrium, the following will occur: - Answer-The transverse component will increase In MRI, substances respond to a specific radio frequency which is known as: - Answer-Resonance Frequency The introduction of gadolinum based contrast enhancement agents by intra-venous injection can involve passing through as abnormal blood brain barrier. The tissue compartments involved are the: - Answer-intravascular to interstitial T2 is the measurement of time for the transverse compnent of the nmv to decrease what percentage of its maximum value after application of a 90* radio-frequency pluse? - Answer-37% In the USA the MRI systems main magnet field and the vector that represents it is symbolized - Answer-B0 the resonance frequency of any substance in a magnetic field can be calculated by employing the - Answer-Larmor equation in a pulse sequence transmitting a initial 90-degree radio frequency pulse will cause the nmv to: - Answer-shift in both size and direction which type of electromagnetic coils are designed to stimulate and detect an MRI signal - Answerradio frequency coilstissues that are less efficient at spin-spin interactions because they contain more free water such as cerebral spinal fluid should have - Answer-High T2 values and produce hyper-intense signals magnetism can be defined as the ability of certain substances to attract - Answer-iron Cobalt and nickel the purpose of magnetic resonance angiography is to image the - Answer-blood flow the strength of very large magnetic fields like those employed and MRI systems the SI unit most commonly used is - Answer-Tesla