Fov - Samenvattingen, Aantekeningen en Examens

how do you reduce beam hardening 1. Increase dose 2. Reduce collimation--Reduce slice thickness 3. Increase window width At what level does the abdominal aortal bifurcate? L4 What is the typical scan delay after injection of contrast media for studies of the liver? 30-45 seconds What window settings provide the best tissue differentiation within the liver? window width= 140, level= 60 What is the window settings that provide the best bone window for the pelvis? ...

The exposure rate of an activity of 1 millicurie (mci) measured at 1 centimeter (cm) is called - The exposure rate constant (ERC) For positron emitters, the exposure rate constant (ERC) is about 6 R/h per milli- curie at 1 cm. The exposure rate of a 10 mci dose of F-18 is approximately six times greater than that of a 10 mci dose of Tc-99 m at a distance of approximately 8 inches. Quantitative bias that refers to the underestimation of counts density which differs from what they should be ...

When doing a study on a patient's knee you notice that the image is fuzzy (TOO MUCH PARTIAL VOLUME AVERAGING). Which of the following changes would improve your image the most when repeating the sequence? correct answersDecreasing the thickness 1/2 mm If we have a voxel of .78mm x .78mm x .1mm, we would have an anisotropic voxel? correct answersTrue If you change the NEX from 2 to 4, what is the resulting scan time change? correct answers2x Which of these is NOT a consequence of decrea...

RCIS Question and answers already passed RCIS 0.5 mm lead equivalent - correct answer Provides 95 % shielding from x-ray Color badges - correct answer Give a good measure of eye exposure Catheters wt high take off - correct answer Amplatz, JL5 X- ray beam that controls amount os electrons boiled off -- effects patient dose/ pt exposure - correct answer Milliamperage (mAs) X-ray beam that controls quality of pictures - correct answer Kilovoltage potential (kVp) Attenua...

MRI Armrit { ARMRIT 2024} Practice Exam Tested Questions Correctly Answered An analogy for the decoding of the MR signal through Fourier transform is: A) Basilar membrane processing sound B) None deciphering C) Kidneys processing fluids D) Liver processing alcohol A) Basilar membrane processing sound For the following Spin-Echo protocol: Fov: 320 TE: 25 TR: 500 ST: .5m Slice Gap: 1mm Slice #: 9 Nex: 4 Matrix: 192 Decreasing the NEX will: A) Increase SNR and Resolution B) Decre...

MRSO prep exam IEC DB/DBA limits for MRI - correct answer 140 DB 99 DBA parameters to reduce noise in MRI - correct answer -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 - correct answer Most noise EPI/DWI least noise spin echo sequence an increase in slew rate and gradient amplitude ca...

Quantitative bias that refers to the underestimation of counts density which differs from what they should be is called: - ANSWER-Partial-volume effect PVE is caused by the finite spatial resolution of the imaging system which reveals how far the signal "spills out" around its actual location. The signal spreading falsely increases the object size and volume. Image sampling, where voxels in ROI include the signal from underlying tissues, also contributes to the phenomenon known as partial-vo...

4 image considerations of image quality SNR CNR SR Scan time Which extrinsic factor will have greatest affect of SNR Coil type Which type of tissue will produce lowest SNR Muscle White matter Gray matter Cortical bone Cortical bone A coarse matrix will have High # of freq/phase Low # of freq/phase Large pixels High SNR High # of freq/phases Doubling slice thickness will increase or decrease SNR? Increase SNR Increasing TR will decrease or increa...

JAVELIN WEAPON SYSTEM GENERAL INFO The Javelin is a _______ and _______, ______ _______, ______ ______ anti-tank weapon. - Fire forget man portable medium range The Javelin is capable of destroying.... - Current and projected armor and hovering helicopters What is integrated into the Javelin CLU - A day and night sight that allows for day/night operations and during limited visibility conditions What is the max effective range for the Javelin - 2,500 m What is the Min effe...

For the following spin-echo protocol: FOV: 320/ TR:500/ TE:25/ SliceThick.:5mm/ Slice Gap:1mm/ Slice.#:9/ NEX:4, Matrix:192 Decreasing TE will: a. Decrease the # of allowable slices. b. Increase the # of allowable slices. c. Increase scan time. d. Decrease scan time. - Answer-b. Increase the # of allowable slices. A linear relationship between frequency and position is superimposed on Bo by the Gp. The H protons' relative precessional frequencies determine: a. Phase coherence. b. Phas...