MRSO prep exam 2023 with 100% correct answers

IEC DB/DBA limits for MRI 140 DB 99 DBA parameters to reduce noise in MRI -thicker slices -larger FOV -smaller matrix -parallel imaging -reducing bandwidth (increasing TE) -active noise reduction -Low SAR RF mode (increase in echo spacing)-thicker slices MRI sequence that produces the most and least noise in MRI Most noise EPI/DWI least noise spin echo sequence an increase in slew rate and gradient amplitude causes an increase in Peripheral nerve stimulation stimulation of the eyes in a patient causing an appearance of flashing lights magnetophosphenes stimulation of the vestibular system causing a vestibular ocular reflex where the eyes rapidly move side to side nystagmus what force causes the noise heard in MRI lorentz forces B1+rms the amplitude of the B1 frequency over 10 seconds--the intensity of the changing magnetic field in our patient will determine the amount of energy transferred to our patient SAR energy per patient mass measured in J/Kg SAR is measured per sequence SAR limits: whole body--receive only coil & integrated Body coil whole body measured over 6 minutes first level operating mode 4 w/kg normal operating mode 2 w/kg SAR limit for head is 3.2 w/kg in both first level and normal operating mode