Compounds of Formula I:and pharmaceutically acceptable salts and solvates thereof, wherein R1, R2, R3, R4, R5, R6, R7, R8, R9, and R10 have the meanings as indicated in the specification, are useful for treating diseases mediated by blockade of the epithelial sodium channel. The transparent main body includes a first surface and a second surface. Non-rigid registration deformation fields are calculated to register a selected image slice with corresponding slices in each phase.