Phase FOV

Select a Phase FOV to reduce phase steps and thus reduce scan time. Use a small Phase FOV for scans with anatomy smaller than the FOV in the phase direction, such as extremities, spines, axial, and coronal heads. Also use a reduced Phase FOV for high resolution images in a short scan time when combined with a symmetrical matrix.

• Decrease the Phase FOV and Signal-to-Noise Ratio (SNR) is reduced by approximately: – 14% for 0.75 Phase FOV, – 30% for 0.5 Phase FOV.
• Decrease the Phase FOV in Echo Planar Imaging (EPI) acquisitions to decrease geometric distortion and increase spatial resolution.
• Phase FOV requires more precise placement of anatomy in the center of the Field Of View (FOV). This is easily accomplished with FOV center offsets.
• Phase wraparound occurs if anatomy exists outside the new, reduced FOV. SATuration Pulse (SAT) pulses placed in the phase direction can reduce the aliasing artifact.
• Typically a Phase FOV less than one is not selected on a sagittal or coronal if phase and frequency are swapped.

Table 1. PFOV image legend

Callout	Description
1	Phase
2	Frequency
A	Phase and Frequency swapped with a Phase FOV of 1
B	Phase and Frequency swapped with a Phase FOV of 0.75