The quality of a surface mesh can be checked in Patran by using the following commands:
Elements -> Verify -> Element -> Jacobian Ratio -> Apply
The surface mesh should have a maximum of near 1.00.
If the model exhibits elements with values in the hundred or thousands these are bad elements.
A value of 1.4 may be acceptable, however a value below 2 maximum may be allowable. (the upper limit requires verification by the user to establish a best practice).
An excerpt from an MSC help section:
Jacobian Ratio The ratio of the maximum determinant of the Jacobian to the minimum determinant of the Jacobian is calculated for each element in the current group in the active viewport. This element shape test can be used to identify elements with interior corner angles far from 90 degrees or high order elements with misplaced midside nodes. A ratio close or equal to 1.0 is desired.