What is this sequence called?
This sequence, with multiple parallel lines across it, is referred to by different names, including "hatch" or "grid." Sometimes two sets of lines are orthogonal to each other, creating a true grid.
How is it created?
To create the grid, signal is nulled in straight lines prior to acquisition of the cine sequence. This process has been termed "myocardial tagging."
What is the purpose of this sequence?
One purpose is to aid your eye in assessing myocardial motion. Contraction or relaxation of the geometric shape superimposed on the myocardium allows one to more confidently assess areas of hypokinesis or dyskinesis.
What is the sequence showing in this case?
Normally, the pericardium should slide past the myocardium. When this happens, the line across the ventricular pericardium and myocardium in diastole should become discontinuous. In this situation, the intersection of the line between the pericardium and myocardium never "breaks" or "slides." This indicates that the pericardium is stuck to the myocardial surface.
In this cine grid sequence, the pericardium is not sliding past the myocardium as expected. This is shown by the lines extending through the pericardium and myocardium. They do not break at any point in the cardiac cycle.
(A septal bounce can also be seen)