Hi, welcome to HCM.
is circular in shape. Diffuse disc bulge means increase in its diameter in all directions. It is important only on posterior aspect where it causes effect on spinal canal
In your case disc between L3 - l4 has such bulge with effective compression of spinal canal. At its lateral aspect it is causing compression of origin of nerve
which is main reason for your symptoms.
Please consult your orthopaedician for further management.
Hope I have answered your query.