Hi and welcome to HCM.
It shouldnt cocnern you. this is common finding even in healthy peope. ELevated diaphragm can be caused by your previous surgery but if there are no symptoms then you shouldnt be worried. Linear fibrosis
can be sign of previous healed infection or cronic bronchitis/emphysema
.Also some vascular and lymph
nodes enlargements can be detected as linear fibrosis but as I said it doenst mean much if your lung capacity is undisturbed. Wish you good health.