MRI Parameters Chart *Need to Memorize*

SNR increases

If you increase TR, what will happen to SNR?

Scan time increases

If you increase TR, what will happen to scan time?

No effect

If you increase TR, what effect will that have on spatial resolution?

SAR decreases

If you increase TR, what will happen to SAR?

T1 weighting will decrease.

If you increase TR, what will happen to T1 weighting?

Number of available slices will increase.

If you increase TR, what will happen to the number of available slices?

SNR will decrease

If you increase TE, what will happen to SNR?

Scan time will increase

If you increase TE, what will happen to scan time?

No effect.

If you increase TE, what effect on detail does that have?

SAR will reamin unchanged.

If you increase TE, what will happen to SAR?

T2 weighting will increase

If you increase TE, what will happen to T2 weighting?

Number of available slices will decrease.

If you increase TE, what will happen to the number of available slices?

SNR will increase

If you increase FOV, what will happen to SNR?

Scan time will remain unchanged (unless voxel size is constant)

If you increase FOV, what effect will that have on time?

Spatial Resolution will decrease.

If you increase FOV, what will happen to spatial resolution?

Increasing FOV has no effect on SAR.

If you increase FOV, what will happen to SAR?

The amount of area covered will increase if the FOV is increased.

If you increase FOV, how does that affect the coverage area?

SNR will increase

If you increase NSA/NEX, what will happen to SNR?

scan time will increase

If you increase NSA/NEX, what will happen to scan time?

No effect on detail.

If you increase NSA/NEX, how will spatial resolution be effected?

SAR will increase

If you increase NSA/NEX, what will happen to SAR?

motion will increase?

(need to look up)

If you increase NSA/NEX, what will happen to motion?

SNR will decrease

If you increase the ETL / TSE, what will happen to SNR?

Scan time will decrease

If you increase the ETL / TSE, what will happen to scan time?

No effect

If you increase the ETL / TSE, what effect does that have on spatial resolution?

SAR will increase

If you increase the ETL / TSE, what happens to SAR?

Blurring will be increased

An increase in ETL/TSE has what effect on blurring?

SNR will decrease

If you increase TI (inversion time), what will happen to SNR?

scan time will increase due to an increase in TR

If you increase TI (inversion time), what will happen to scan time?

Increasing TI will not have any effect on detail (spatial resolution).

If you increase TI (inversion time), how will that effect spatial resolution?

SAR will remain unchanged.

If you increase TI, what will happen to SAR?

Tissue saturation will increase.

If you increase TI, what will happen to tissue saturation?

SNR will decrease

If you increase the phase matrix, what will happen to SNR?

scan time will increase

If you increase the phase matrix, what will happen to scan time?

Spatial resolution will increase

If you increase the phase matrix, what will happen to spatial resolution?

SAR will (indirectly) increase

If you increase the phase matrix, what will happen to SAR?

Truncation / Gibbs artifact will decrease

If you increase the phase matrix, what will happen to Truncation (Gibbs) artifact?

SNR will increase

If you increase the flip angle (FA), what will happen to SNR? (approaching 90 degrees)

scan time will remain unchanged

If you increase the flip angle (FA), what will happen to scan time?

Flip angle has no effect on spatial resolution

If you increase the flip angle (FA), what will happen to spatial resolution?

SAR will increase

If you increase the flip angle (FA), what will happen to SAR?

Susceptibility (to metal artifacts) will decrease

If you increase the flip angle (FA), what will happen to susceptibility?

SNR will decrease

If you increase the rBw, what will happen to SNR?

Scan time will decrease

If you increase the rBw, what will happen to scan time?

Spatial resolution will remain unchanged

If you increase the rBw, what will happen to spatial resolution?

SAR will decrease

If you increase the rBw, what will happen to SAR?

Both chemical shift and metal artifacts will decrease.

If you increase the rBw, what will happen to chemical shift and metal artifacts?

SNR will decrease

If you increase PI (parallel imaging) factor, what happens to SNR?

Scan time will decrease

If you increase PI (parallel imaging) factor, what happens to scan time?

spatial resolution will remain unchanged

If you increase PI (parallel imaging) factor, what happens to spatial resolution?

SAR will decrease

If you increase PI (parallel imaging) factor, what will happen to SAR?

DWI susceptibility artifacts will decrease

If you increase PI (parallel imaging) factor, what will happen to DWI susceptibility artifacts?

SNR will decrease

If you increase DWI b-value, what will happen to SNR?

scan time will increase (due to an increase in TR)

If you increase DWI b-value, what will happen to scan time?

Spatial resolution will remain unchanged

If you increase DWI b-value, what will happen to spatial resolution?

SAR will remain unchanged

If you increase DWI b-value, what will happen to SAR?

Increasing the b-value will increase the chances of detecting a stroke / neoplasm

If you increase DWI b-value, how will that effect the detection of a stroke / neoplasm?

SNR will decrease

If you increase the # of SAT bands, what will happen to SNR?

scan time will increase due to an increase in TR

If you increase the # of SAT bands, what will happen to scan time?

spatial resolution will remain unchanged

If you increase the # of SAT bands, what will happen to spatial resolution?

SAR will increase

If you increase the # of SAT bands, what will happen to SAR?

motion and flow artifacts will decrease

If you increase the # of SAT bands, what will happen to motion / flow artifact?

SNR will increase

If you increase slice thickness, what will happen to SNR?

scan time will not change

If you increase slice thickness, what will happen to scan time?

spatial resolution will decrease

If you increase slice thickness, what will happen to spatial resolution?

SAR will remain unchanged

If you increase slice thickness, what will happen to SAR?

Partial volume artifact will increase

If you increase slice thickness, what will happen to partial volume artifacts?

SNR will remain unchanged

If you increase the # of slices acquired, what will happen to SNR?

scan time will increase ( due to an increase in TR)

If you increase the # of slices acquired, what will happen to scan time?

Spatial resolution will remain unchanged

If you increase the # of slices acquired, what will happen to spatial resolution?

SAR will increase

If you increase the # of slices acquired, what will happen to SAR?

The anatomic coverage will increase

If you increase the # of slices acquired, what will happen to anatomic coverage?