MRSO: Exam 2 with complete solution 2023

MRSO: Exam 2 with complete solution 2023 What is the name of the gradient coil used to produce sagittal and coronal images? a. Transverse coil b. Golay coil c. Maxwell coil d. Receiver coil - correct answer b. Golay coil ("saddle coil") Which of the following is able to handle the most RF heating? a. elderly b. adult c. obese adult d. neonate - correct answer d. neonate Which of the following techniques can be used to increase the echo spacing? Select all that apply. a. Increase the TR b. Decrease receiving bandwidth c. Increase receiving bandwidth d. Use a receive only coil e. Increase field of view f. Increase flip angle - correct answer b, e Decreasing the receiving bandwidth will be lengthening the sample time. This may force us to increase our TE as well as the TR. Increasing the field of view will also allow for longer echo spacing. The differences in magnetic field strength as you approach the MRI unit is termed what? a. Spatial magnetic gradient b. Gauss line c. RF energy d. Gradient coils - correct answer a. Spatial magnetic gradient Measured in dB/dx Which of the following produce the greatest chance for peripheral nerve stimulation? a. Conventional spin echo b. Fast spin echo c. Gradient echo d. EPI - correct answer d. EPI A deflection of 45 degrees in a tested implant indicates that it deflects at a force equal to what? a. 0.5 gravity force b. 2 gravity force c. 0.25 gravity force d. 1 gravity force - correct answer d. 1 gravity force 4T/m is equal to what? a. 4000 G/cm b. 4G/cm c. 40 G/cm d. 400 G/cm - correct answer d. 400 G/cm 1T = 10,000 G 1m = 100 cm Therefore, 1 T/m=10,000G/100cm This means that 1 T/m=100 G/cm How do we calculate the maximal spatial gradient? a. dB/dx * B b. dB/dt * W/kg c. W/kg d. B - correct answer a. dB/dx * B What group issued the ACR white paper MRI safety? a. ACR Blue Ribbon Panel on MR safety b. FDA c. OSHA d. EPA - correct answer a. ACR Blue Ribbon Panel on MR safety Which of the following is true of a gad contrast osmolarity? a. Less than blood b. Greater than blood c. Less than water d. Equal to blood - correct answer b. Greater than blood (and greater than water) Which of the following is true if we increase the field of view from 200mm to 400mm? a. We reduce patient heating b. We use a stronger time-varying gradient magnetic field c. We use a weak time-varying gradient magnetic field d. We increase the patient heating - correct answer c. We use a weak time-varying magnetic field.