MRSO Practice Exam |Question and Answers| VERIFIED!! ||

MRSO Practice Exam |Question and Answers| VERIFIED!! || IEC DB/DBA limits for MRI *Ans* 140 DB 99 DBA parameters to reduce noise in MRI *Ans* -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 *Ans* Most noise EPI/DWI least noise spin echo sequence an increase in slew rate and gradient amplitude causes an increase in *Ans* Peripheral nerve stimulation stimulation of the eyes in a patient causing an appearance of flashing lights *Ans* magnetophosphenes stimulation of the vestibular system causing a vestibular ocular reflex where the eyes rapidly move side to side *Ans* nystagmus what force causes the noise heard in MRI *Ans* lorentz forces B1+rms *Ans* 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 *Ans* energy per patient mass measured in J/Kg SAR is measured per sequence SAR limits: whole body--receive only coil & integrated Body coil *Ans* 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 SAR limits local transmit/receive coil *Ans* local coil measured over 6 minu