1.  Probe Selection 

The phased-array probe is most suitable for pericardial effusion imaging. 

be

The curvilinear probe can, also, image the effusion as well particularly for the subcostal window due to the distance from the pericardial space.  However, recall the curvilinear probe is not designed for temporal resolution, so cardiac motion will not be smoothly captured.

All standard cardiac sonographic windows can image different regions of the pericardial space.

The subcostal 4 chamber view, in general, is the first view that most users utilize to interrogate for a pericardial effusion.  The reason is this sonographic window is easier to obtain than the parasternal or apical 4 windows.  In addition, it allows one to image the majority of the pericardial space in one view and, also, the most dependent regions of the heart (adjacent to the right atrium and right ventricle) where a non-loculated effusion tend to gravitates towards.

Once you obtain the subcostal 4 chamber view, sweep through the entire pericardium to interrogate the space thoroughly.  If you do see a what appears to be pericardial fluid, verify it from another angle (another sonographic window) to ensure that it is not an artifact, or a mimic.